Does bluetooth work in an aluminum camper? Ideally, I'd like to monitor bluetooth-enabled devices in my trailer, while I'm driving in my TV.
I've recently purchases a couple of lithium batteries for my Camplite 14DBS. I know that I need a DCDC converter to charge the battery from the TV. I also need a solar charge controller that will be compatible with the lithium batteries.
I've been considering two combinations of equipment:
1) Victron Smart Orion DCDC converter (18A) + Victron Bluesolar charge controller (30A with bluetooth dongle)
2) Renogy 20A DCDC converter (no bluetooth) + Renogy Rover charge controller (40A with bluetooth dongle).
The Victron equipment is considerably more expensive, but there are a few things that are making me consider it nonetheless. My concern is that, unlike the Renogy Rover (which has a built-in display), the Victron relies entirely on bluetooth for configuration and monitoring. I know that the Victron Bluesolar has an optional display module, but I'll likely be using that port for a bluetooth dongle... I like the idea of bluetooth dongles, because it allows me to "turn off" bluetooth when I am not using it.
It would be a real bummer to spend additional money for equipment that depends on bluetooth, only to realize that it will only work if I'm holding my cellphone next to it!
General comments about Victron vs. Renogy are welcome too! Thanks!
Due to Bluetooth's inherent distance limitations as well as the effect of being inside an aluminum cage, I suspect that you will not be able to get a signal sitting in the driver's seat of your TV.
But more importantly, why are you installing a DC2DC charger? Presumably to limit current from your TV.
If you connect the DC2DC charger to the circuit that supplies power to the trailer through pin 4 of the 7 pin connector, you may not get enough current to worry about. First it is typically a 10 gauge cable protected by a 30A fuse that is connected to the TV's battery/alternator circuit, so you can never get more than 30A, you will blow the fuse. But a 20A DC2DC charger will protect from that happening.
But I don't think you will see that much current anyway due to voltage drop along that long 10 gauge wire from the TV to the TT. When I hook up my TV and start the engine with a half discharged FLA TT battery, I typically get 10-15 amps which drops as the battery gets charged up to about 5 amps. If a lithium battery tried to pull 30 amps the voltage drop would be about 1.2 volts which would bring the charging voltage down from about 14 at the alternator to 13 volts at the battery. Can a lithium battery accept 30 amps at a 13 volts charging voltage. Not sure.
I would first get a clamp on DC ammeter and test the current in that wire with the Li battery near fully discharged. But you might blow the fuse. At least you will know that won't work :).
The only way to get significant charging current is to run a separate, large gauge wire, maybe #4 back to the TT's battery. In that case you might get enough current to justify a DC2DC charger. But maybe not depending on the TV's alternator. Some can output an additional 50 amps with no harm. If the alternator were trying to push 50 amps through a #4 wire, the voltage drop would then be about a half a volt which should allow for that amperage.
If you go this route, before installing a DC2DC charger, see what the alternator case temperature rises to at idle (that is the riskiest situation) when the Li battery is pulling 50+ amps. If it stays below 200 F, you are ok.
David
I agree with David there is no possibility of BT making its way out of the camper and into the TV. Too much metal!
I think the DC-DC converter's main job in this setting will be to provide the charging profile needed by lithium batteries. The bulk-absorb-float times and voltages are different than those needed by lead-acid batteries and a programmable DC-DC converter solves that problem to take the best care of the lithium batteries. Because of this, you should install the DC-DC converter at the battery to handle all the charging needs, both from the TV and from shore power. The DC-DC converter will also handle the current limiting chore covered by David. That certainly is potentially an issue with lithium battery charging because they can accept extremely high currents.
I have and like Victron equipment and find the VictronConnect app user-friendly (and free). I use an old iPad hooked up to the Victron equipment via BT to monitor the charge controller and batteries. Victron also makes the BMV 702 monitor as a dedicated readout. I did a separate monitor (iPad) simply because I find my iPhone is pretty busy on trips and I didn't want to add yet another thing I had to use it for.
The only Renogy equipment I have is one of their flexible, portable 100W solar panels. Works great, but I have no experience with Renogy electronics.
So, I think you'll be happy with your setup if you manage expectations and don't try to monitory things from the TV. ;)
Thank for both for replying... I've included responses for the DC2DC converter and Bluetooth testing below.
DC2DC Converter:
Lithium likes to be charged at 14.2V to 14.6V... so a 10AWG wire might have enough voltage drop to present a significantly lower voltage at the battery. It is my understanding that they would still get charged, but not necessarily a full charge. The data sheet for the batteries says that they will have a voltage of 13V when they have been depleted to 30%. Lithium batteries have a low internal resistance. Apparently they have the ability to sink current faster than lead acid batteries. I understand that the 10AWG may limit current due to voltage drops, but I'm not sure I would want to depend on this. I've read that there is a danger of burning out your alternator, although I guess that the 30A fuse might keep that from happening. The DC2DC converter would address both issues... it would consume more current so that it could generate 14.2-14.6V to the battery, while still limiting the current (20A on the output, probably higher current (25A?) on the input). The Renogy has a feature to cut this in half, if need be. I would plan to put the DC2DC in the TT next to the lithium battery. I'll be sure to check the alternator case temperature. I've been wondering if I should get a clamp ammeter, and I think that you have just convinced me. However, I'm a bit squeamish to try to get 50A of charging current. I'd rather have slower charging times and a little more peace of mind. Of course, in the future I might wish that my piece of mind was larger!
Question... If I use a DC2DC converter, is it really necessary to attach a separate wire to the alternator? If so, should I run this to the 7-pin connector directly? If so, wouldn't that bypass the 30AMP fuse? Or would it be best to use a separate connector (like an Anderson plug)? Either way, should I disconnect the existing (fused) wire to the 7-pin connector?
Bluetooth Test:
Today I used a high-tech approach to testing bluetooth reception... it included my iPhone and my wife's fit-bit wristwatch. I used the fit-bit as a bluetooth source. I downloaded a free app called "Bluetooth BLE Device Finder" on my iPhone. It's supposed to help you find lost BT devices. The hard part was finding out which device was my wife's fit-bit... I had to put it in an empty aluminum cat-food can (with another can on top) to see which signal went away.
I laid in on the counter in my trailer, put my cellphone next to it, and looked at the "signal strength" associated with the fit-bit. It was around 72. I then put the fit-bit on the aluminum floor of the TT, where I planned to mount the DC2DC. The aluminum floor may have interfered with the BT signal, because I got a signal strength around 53. I then went outside the TT (closing the door and leaving the fit-bit on the floor of the TT) and stood right next to where I thought the fit-bit might be... the strength was around 35. I walked around to the other side of the TT (driver's side of the TV) and the signal strength was 19. I got inside the truck and the signal strength was between 0 and 5. (The second time I tried the test, the fit-bit strength was 0, and it dropped off the list of observed devices). I'm inclined to think that both distance and metal are attenuating the signal. When I stepped inside the house (which has a brick front), the signal dropped significantly, so I think that the BT signal might have problems getting through other materials as well.
I gather that I would not be using a Victron device while driving in my TV to monitor charge status of my batteries in my TT... not reliably, anyway. This was a feature that I was hoping would help justify the much higher cost.
AC2DC Converter and Solar
I know that I need to be concerned about shore power. I've purchased a Progressive Dynamics PD4045 power center for lithium, but it is only single stage (14.6V). I plan to check the batteries 2-3 hours after they have been charging, and switch them off 1/2 hour after they reach 14.4V so the cells have time for self-balancing. I could buy a two-stage PD9145 that is deck mounted, but am not sure how I'd wire this into the existing power center.
As mentioned in my initial post, I'm also looking into solar controllers... the catch is that all of the "charge" devices operate at slightly different voltages between between 14.2V and 14.6V. I may or may not be able to tweak them. I'm thinking of having them all on 275A cutoff switches, so that I could keep sources from interfering with each other. If my AC2DC operates at 14.6V (not configurable), then will it see my solar controller as a current sink, if it is only operating at 14.2V? Granted, they probably would not both be functioning at the same time, but I do wonder about this.
See "Cage, Farraday"
RV Squirrel:
Wow, that was an excellent summary of Merlin and my thoughts on the subject. Not sure you really need our help anymore, but since you asked:
If you want to use the 7 pin connector and the TV's 30A circuit to pin 4, then install your 20A DC2DC right at the TT's battery. That is probably the easiest solution as it will give you a steady 20A to the batteries, appropriately regulated to 14.2-14.4V.
If you want more, then run a totally separate circuit from the TV's battery/alternator output with #4 or6 gauge wire, protected by a 100A fuse or smaller back to the bumper of your TV then with Andersen connectors to near the TT's battery where you install a bigger, maybe 40A DC2DC to the TT battery. Blank off the existing 10 gauge wire. Lots of work for not much gain.
You might want to look into Redarc's (or is it Renogy?) combined MPPT solar controller and DC2DC charger. Apparently it has separate inputs for each source and manages them together. If you use their 20A version, you will be limited to about 250 watts of solar. Although I don't see any problem with separate sources and a DC2DC and a MPPT controller in parallel. It happens all of the time in the boating world with separate solar, propulsion engine alternator and generator powered shore power chargers running all at once with all outputs in parallel.
Keep us informed as you move along with this project. I have been members of several RV sites, and have never seen the results of a DC2DC charger install reported.
David
I very much appreciate the opportunity to pick the brains of folks with understanding and experience. My wife is getting tired of hearing me mutter to myself about this.
From what you've said, it sounds like I could use the 7 pin connector output for a 20A DC2DC. I'm glad to hear that, because I'm trying to avoid going too far down a rabbit-hole. If this isn't optimal, then I'll deal consider a separate/heavier gauge later.
Still wondering which approach to use.... yesterday I was thinking Renogy, but today I'm thinking Victron. The crazy thing is that the DC2DC Orion always broadcasts BT, and when I need it most (in my TV) I may not have sufficient signal to make use of it.
If I go with Victron, then I will need to decide between the 30A and 50A controller. I have three solar panels, but am planning a design that will accommodate 4. This will require a controller that does 30Amps, which is the high end of what the 30A Victron will do. I'm wondering if I should spend $100 more for the 50A Victron. I am considering the Bluesolar with the BT dongle, because there is no easy way to turn off BT in the Smartsolar. Victron claims that you can upgrade firmware over BT from your cellphone, but I'm wondering if anyone has actually done this.
Thanks for the insight about running sources in parallel. Renogy does market a "Dual Input DC-DC On-Board Battery Charger with MPPT" (30A and 50A models). However, it has a few limitations in my opinion:
1) Solar voltage is limited to 25V, which means that you would always need to connect panels in parallel. I plan to do this anyway, but it would be nice to have the option to connect them in series if you wanted to.
2) The interface uses the BT-2 with "Renogy DC Home App", which seems to require you to walk through a lot of unnecessary info in order to do basic stuff. From what I've read, the BT-1 with the old BT App seems to be more straightforward.
3) From what I've read, the dedicated DCDC charger (in 20A and 40A models) are real workhorses. However, the performance of this hybrid device is questionable for DC to DC conversion. I've seen reviews that claim that the device does not actually generate the rated charge current when the input voltage drops... which is precisely one of the reasons why you would want a DC2DC!
4) The device will charge your TV battery once it is finished with the TT battery. Some consider that a feature... to me it sounds a little creepy.
5) From a redundancy perspective, it's nice to have two different chargers... if you are away from shore power, then you can switch between DC2DC and solar if one of the devices does out.
A couple random followups......
I have a simple 30A circuit breaker on the connection between the solar charge controller and the batteries. I use it as an on/off switch for the solar. I find I never need multiple charging sources going into the batteries so whenever I'm hooked up to shore power or TV power, the solar is off.
https://www.amazon.com/Blue-Sea-Systems-Circuit-Breakers/dp/B000KOVBXQ/ref=sr_1_8?crid=QXQ1VWTL4TEY&keywords=30a+dc+circuit+breaker&qid=1648430723&sprefix=30A+dc+c%2Caps%2C95&sr=8-8
Regarding your number 4 in the list.....there is a relay in the TV to trailer wiring that prevents power from going from the trailer to the TV. Your TV battery will never be charged with the setup you're considering.
One of the other members on here is planning to use the TV as a generator for the batteries by running a separate external wire via an Andersen connector from the TV battery to a DC-DC charger at the trailer battery. It's to be used only at a campsite while stationary, so it's not meant for going down the road. Have you considered that option for battery charging?
I agree with David that running a separate wire from the TV to the trailer for charging while driving would be a lot of work for not much gain. Skip that.
Don't worry about running a 30A Victron CC at close to capacity. They are overbuilt and can handle the current so long as you provide space for adequate cooling. The worst that will happen is a bit of amperage clipping.
I'm not surprised at your BT signal tests. Metal, brick, low-E windows, and distance all attenuate the typically weak BT signal significantly (and attenuate Wifi too).
What would you like to be able to monitor while sitting in the TV? I ask because I've found that voltage is not very useful for lithium battery monitoring. Their voltage has a fairly flat curve while discharging and then a fairly steep decline at the end of their capacity. Use of a shunt-based state of charge monitor designed for lithium is an excellent alternative to voltage. As I mentioned previously, Victron makes the BMV-702 and one of those mounted in the battery box would tell you everything you normally need.
Muttering to yourself is a good sign. The problem comes when you start to argue with yourself and lose the arguments.
I've used my TV to charge my TT in a pinch, but I'd rather not depend on this. With a DC2DC charger I can do this, although with an 18A or 20A unit it might take awhile, but it's still doable. I must admit that with my Silverado it seems that I need to do some strange things to get current flowing out the 7-pin connector... I need to turn on "tow mode" and turn on the headlights (sometimes it helps to stand on one leg ;-)
Glad to hear that my TV battery is protected from current from the TT.
At first, I was thinking that it would be nice to use BT to monitor the voltage to see when it reached 14.4V, so that I knew when the lithium battery charge was "ending" the absorption stage and should be put into float (so as to not overcharge the battery). However, I now realize that this is moot... the Victron is two-stage and would automatically go into float (without me monitoring it), and the Renogy (which is one-stage) does not support BT so there wouldn't be any BT signal to monitor. The BMV-702 sounds neat... but right now I have an AiLi battery meter/shunt that I hope to reprogram for the lithium batteries.
Your thoughts tend to touch upon things that I've been wondering. I've attached a block diagram, including all of the components including switches and fuses. Items in yellow are especially questionable. The inverter is not there now, but may be added later.
I've included switches on power sources so that I can shut them off, just as you do with solar. Is your switch on the input or the output of the solar controller? I've included a switch on the battery so that I can keep them from being overcharged if I'm connected to shore power. Renogy recommends putting fuses on either side of the solar controller, but Victron only mentions putting them between the solar controller and the battery. Both Renogy and Victron recommend putting fuses on either side of the DC2DC, but I'm wondering... Do I need a fuse on the input if I'll be getting this from the fused 7 pin connector. Also, the Victron user manual suggests 60A fuses, which sounds excessively high.
I've wondered about using circuit breakers instead of switches/fuses. I've read a couple of things that suggest that fuses are better because breakers can wear out if you use them as switches often. Also, there if heard that in "marginal" situations, a breaker may wear out more quickly because it will be cycling often, but I'm not sure if this is a good argument. Do you recommend breakers over switches/fuses? If I were to use switches/fuses, which one should be closer to the power source? (I.e., solar controller, fuse, then switch... or solar controller, switch, then fuse)?
My space is limited... I plan to mount the equipment on a board that separates the AC/DC distribution cabinet area (with the Progressive Dynamics) with the cabinet area under the sink (with batteries on the rear wheel-well). I've attached a picture for this as well (imagine sticking your head in the bottom cabinet, and looking over your left shoulder). Victron recommends have 4" above and below their units, and this will only give me 2.5". However, I plan to cut out the back of the board so that air can circulate through the cooling fins from the other side of the board as well as the front. I still need to figure out where to put the fuses... this makes it tempting to replace the switches with circuit breakers.
(//)
My thoughts on your wiring diagram:
You sure have a lot of switches and fuses. I am a simplicity kind of guy and I would remove most of them and only put what is technically required to protect the wiring. In some cases this might mean increasing the wire size, but its only a few feet. This is what I would do:
Use nothing smaller than #8 wire- to the converter box and its DC loads, solar controller and the DC2DC charger, all except for the future inverter. Put a 75/80 amp circuit breaker near the battery to serve all of these loads/sources. #8 is good for 80 amps. Do not install any switches. If you need to diagnose or repair something, disconnect it with a screw driver not a switch. There is no need for fuses on the TV side of the DC2DC or on the input or output side of the solar panels. #8 is plenty big enough to handle the maximum current that will ever go through those wires.
BTW, the ABYC, the standards body for the boating industry (much, much better than the RVIA) says that if a source is inherently current limiting as is a solar panel, your converter or the circuit from your TV, you don't need a fuse as long as the wire is big enough to handle that current.
For your future inverter, size the wire based on the current it will draw and size the fuse to protect that wire while maintaining a decent voltage drop. You can go as high as a 1 volt drop at max power draw, but I would prefer less.
Your shunt wiring makes no sense. The shunt should be on the battery negative or if you have two batteries after the two batteries are wired together to a single negative. That way ALL of the current goes through the shunt. The shunt creates a tiny voltage drop that is proportional to the current. The meter reads that small voltage but displays the result as current. The meter also needs a positive from the battery to measure the voltage, which is the battery voltage not the voltage drop through the shunt. If the meter is a long way away, you can use #18 wire as the current is nil and put a 5 amp fuse near where the #18 ties into a #8 positive or directly to the battery terminal.
Wiring the solar panels to the controller- I would install all of the panels you ever want to at once. They are cheap enough. If you have four panels I would wire them in series/parallel assuming you have a 50V or greater controller input spec. Use #8 wire from where all four tie together to the controller and #10 from the panels to that tie point. With #8 and series/parallel the maximum current you will see is about 15 amps. The voltage drop for a 20' run from the roof where you tie them all together to the controller is about 0.4 volts which is good. I like to keep it below 0.5V. I assume that the run from the controller to the battery is much shorter, maybe 5' so the voltage drop in that wire will be .3 volts. If it is longer go up a size to keep the voltage drop near 1/4 volt.
Wow, that was a lot of stuff. Hit me again with anything else. This is fun.
David
Thanks for posting all this, by the way. It's always fun spending other folks' money.
In your diagram, you have the 3 sources of power to the batteries in parallel. That's fine, but pull the DC/DC converter out of the trailer hitch source and run all 3 sources to that converter. The sources will still be in parallel, but all going through the DC/DC converter just before the batteries. That will solve a lot of problems you might have otherwise (like your single stage AC/DC converter overcharging the batteries) and it will take good care of your lithium batteries.
The Blue Seas CB I linked to previously is on the output side the solar controller in my set up.
There is no problem with using modern CBs regularly as a switch, on either AC or DC circuits. I suggest replacing each switch/fuse combo in your diagram with a simple CB. Since you have a somewhat complex setup, you might consider centralizing your CBs and wiring into a Midnight Solar Big Baby Box with appropriate sized breakers for each circuit. And, consider using a Midnight Solar Combiner Box for the solar panel inputs to the solar controller.
I don't think you need a fuse or CB on the input side of either the TV power or the solar controller. The TV is already fused and the solar panel current is not that high.
The critical thing for over current protection, either fuses or circuit breakers, is the input(s) and output(s) of the batteries. Those have more than enough amps to do accidental welding or burn up your camper if shorted out. Size the fuses or circuit breakers for the size of the wires and size the wires to handle the maximum current expected, plus a safety factor. I always recommend not skimping on wire size.
The battery management system that's built into your lithium batteries will serve as a battery protect device, so you don't need the separate shown on your diagram.
With regard to having a CB on both sides of the DC/DC converter. Yes. That will allow you to isolate the batteries from the converter for work on the batteries and it will protect the input side from overcurrent from any of the 3 parallel power sources.
Edit: I see David posted wire sizing while I was inventing my response. Good sizing info there!
Here is some wiring mechanics advice:
Use ring terminals on all wires, crimped on with a good wire crimper. Use terminal blocks or strips to connect multiple wires. Consider using one large buss for all negatives and another for all positives. That makes it easier to use my screwdriver approach for diagnosis and maintenance.
For cables, I prefer tinned marine grade stranded cable. Genuinedealz.com used to be my preferred source, but it now seems that they are sold out of almost everything. BatteryCablesUSA.com is another good source and they seem to be stocked ok.
For long runs of + and - use red/black paired cables with a sheath. Unfortunately, BCU doesn't carry that. Maybe a Home Depot or similar will, but it won't be tinned marine grade.
You might want to check out a couple of marine books on the subject. Nigel Calder's book is good. Ancorproducts.com has articles on wiring mechanics. The 12-Volt Bible For Boats by Miner Brotherton is also good.
David
I really appreciate the potshots recommendations! I'd rather make mistakes now then later. By the way, I noticed that the "equipment placement" attachment in my earlier post did not come out quite as planned, so I have replaced it.
First... the shunt. Yes, this isn't drawn correctly. On the trailer, I have it attached to the negative terminal of the battery, with ALL of the loads and current sources going through it. I plan to do the same with the lithium batteries. In the diagram I should have had it immediately after the negative terminals of the batteries. I'll fix it.
I like the idea of putting the battery charge sources through the DC2DC, but probably will not do it for the following reasons:
1) There is no way to turn bluetooth off on the Victron DC2DC! I don't like bluetooth because I don't like to broadcast (literally) the availability of high-cost electronics in my camper. Therefore, I only plan to power the DC2DC when I need it... when I am towing/charging, or when I'm sitting in one place and in desperate need of an alternative to solar or AC2DC.
2) The Victron DC2DC is only 18A or 30A, and the Progressive Dynamics claims that it can charge much more than this (45A?). Feeding this through the DC2DC might be a problem.
3) The Victron user manual makes a scary reference to a "non-replaceable" fuse on the input to the DC2DC. I'm not sure what the advantage is to a non-replaceable fuse, unless it is to protect device downstream of the DC2DC. Whatever the case, I get the impression that this device is vulnerable.
Also, I've just purchased a 2-stage PD9145ALV deck-mounted power supply. I'm going to return the single-stage PD4045. I'll probably need to install an outlet box for the power supply plug, which will be on the same circuit as the 120V receptacles. I'm wondering if I need to make the "reverse polarity" fuses accessible, or if they are only likely to blow during installation.
I'll reconsider the other fuses/switches.
- The DC2DC user manual says to put one 60A fuse between the converter and the tow battery, and another one between the DC2DC and the house battery. I'm going to leave these in yellow (with and circuit breaker on the output side) and try to ask the Victron community about this. They may be redundant with the 80A circuit breaker that you recommend, as well as the 30A fuse at the TV. I agree that it would be good to isolate the output from the batteries (e.g., with a circuit breaker).
- The BlueSolar 100/30 user manual says to "protect" the house battery with a 35-40A fuse. In parallel, the total current for four panels would be over 21A. I'm going to leave the fuses in yellow (with and circuit breaker on the output side) and try to ask the Victron community about this. Again, it would be good to isolate the output from the batteries (e.g., with a circuit breaker).
- I'll consider the Midnight Solar box for the fuses and the solar panels... right now I'm very interested in what takes the least amount of space while still being safe.
I do plan to have a switch for the battery, so that I can switch one or both independently. I've read that you could get into trouble if one is fully charged and the other is not. I gather that the battery management can only "balance" cells when they are near the top of the charge (14.4V), and one that is fully charged can keep the one that is not fully charged from being "balanced".
The battery protect device on my batteries will keep them from being overcharged, but will also put them into "sleep mode". I'm trying to avoid this. In this mode, the batteries can't be recharged unless they are "reactivated". The Renogy DC2DC and Rover solar controller do this, but the Victron equipment does not. I'm looking for an alternative, which may be a simple 12V voltage source. I'm leaning against getting their "battery protect", because it can be easily damaged by anything charging the batteries. Trying to think of alternatives at this point, which may be to simply keep an eye on my existing battery monitor.
David talked about ring terminals, but it appears that the Victron devices do not support this. Are the ring terminals to be used for connections to the terminal blocks (buses)? What about the end that goes into the equipment? Is this where you recommend tinned marine stranded cable? If so, are such cables already tinned, or do you do the "tinning" yourself with a soldering iron?
Thanks for recommending sources of cables and books!
Updated block diagram is attached.
I will address the third from last paragraph:
First you don't want to use solid conductor wire on boats or RVs. Vibration could ultimately crack them. Use the connectors that the device has such as screws that push down on a wire that has been pushed into a hole. But for most other connections, like to the buss or switches or fuses, use ring connectors that are held down by a flat head screw. If you try to install stranded by itself like solid conductor wire, it slips out from under the screw and can ultimately fail and come out.
Tinned wire is tinned at the factory. It is particularly important for boat wire as bare copper strands can corrode and I ultimately lead to a failed connection. But it is not really necessary for RVs, so use what you can find.
Your block diagram now looks much better. Still has unnecessary fuses IMO but they aren't hurting anything. I do think the switch to the converter is necessary to isolate all DC TT loads for storage while keeping solar working to maintain your batteries.
David
This is a great thread. I think we are all learning some new stuff. Based on the latest diagram and a some experience I've had, here are yet more things to consider.
The non-user replaceable fuse in the Victron is also called other names, but if I used them in this post, the forum moderator would not be happy. The fuse is to protect bad things from happening if the input is hooked up reverse polarity. In all of the wiring you do, DO NOT EVER CONNECT ANYTHING REVERSE POLARITY.
Don't use a 1-2 switch or 2 switches on the batteries. To operate correctly in parallel, lithium batteries need to separately fully charged to exactly the same voltage, then connected in parallel and left that way permanently (until replacement). Just connect the + of both batteries to a single on-off switch and run the output of the switch to load.
It's perfectly ok to use multi-connectors like the one in this link to parallel the solar panels if you don't have space to use a standard combiner box. I assume your panels come with MC4 connectors.
https://www.solar-electric.com/multibranch-mc4-connector-pv-azs4.html
I'm glad you went with a 2 stage AC-DC converter. That gives you some options. For example:
I think you can reasonable ditch the use of a DC-DC converter. The main reason for using one (so far as I was thinking), was to standardize the input your batteries are seeing. If you are not using it in series with all the inputs, why have it? Further: 1) Now that you have a 2 stage AC-DC converter, that will work fine for shore power charging. 2) The TV won't fully charge the batteries while under way, but they will be charged and get pretty close They probably would not have fully charged anyway, given the limitations of current from the TV. I don't think it's worth the DC-DC converter complexity to go for that last bit of charge while driving. 3) The solar charger will also take good care of the batteries from the sun. 4) You don't need BT now that you can't monitor from the TV anyway and you have at least an amp meter planned. I would still advocate for a full-on batteries monitor like the BMV702, but I'm a bit off the deep end on wanting data.
It's interesting about the sleep mode thing on your batteries. That's an aggressive BMS and I really don't see why they did that, unless it's to prevent constant on-off charging cycling caused by an unregulated source. Best to regulate the source voltage. (And not incidentally, a good reason to use a DC-DC converter/charger in series with all sources).
And lastly for now, you mentioned a concern about the AC-DC converter being able to supply 45A but the DC-DC converter having a 30A output. That's technically fine. A DC-DC converter in series with that will only draw what's needed and won't be hurt. The worst that can happen is losing a few amps that could be going to the batteries.
And really lastly, I noticed the PD9145ALV has an output voltage of 14.6VDC. That would be too high for the lithium batteries I have (Battle Born and Kilovault). That ok for yours?
And truly lastly, for sure use David's advice on wires.
Merlin,
I saw your response just as I was about to respond to David. In the interest of time, I'm going to post my response and then read yours. I hope that this does not seem inappropriate, but it takes me awhile to digest the good info in these posts!
David,
Thanks for the advice on solid copper wire. BatteryCablesUSA.com seems like a good resource if I choose to by pre-made cables.
Victron recommends the use of "multi-stranded" cable (see picture(//)). I know what stranded is... but do not know if "multi-stranded" is an industry term, or if there is a better term to search for.
I've posted questions about extra fuses/circuit breakers to Victron, but I'm not quite able to understand the answers. I think that they may be in Dutch. Here are the questions and the answers. Maybe you can help me understand them...
Orion (DC2DC)
Question 1) I have a travel travel that I pull with a tow vehicle. I plan to put the Orion-Tr Smart in the trailer, and have it powered with the 12V from the 7-pin connector on the trailer hitch. Do I need a fuse on the input side of the Orion? Or would this be redundant with the fuse for the 7-pin connector in the tow vehicle (presumably 30A)?
Question 2) My batteries are already protected by a circuit breaker (placed near the batteries) that is appropriately sized for the gauge/length of the cable. Would it hurt to have an additional breaker on the output of the Orion? Should this second breaker be sized to the device (18A) or to the cable (which is already protected at 80A at the battery)?
Answer) I would fuse near the source as well. An short whether before or after the charger and batteries as well as vehicle electrical system needs to have some protection.
BlueSolar (MPPT)
Question 3) Do I need a fuse on the input side of the Bluesolar? Other vendors recommend this, but I don't see it in the Bluesolar user manual.
Answer) Solar panels need some sort of disconnect between panels and mppt as they should never be disconnected under load.
I admit that I'm confused by this last response. They have said that there should be a disconnect between the panels and the MPPT, but then they say that the panels should not be disconnected under load. Presumably, a fuse or circuit breaker would break the circuit when it is under load.
I missed what looks like a 1, 2, all switch at the battery. Merlin is exactly right- do not switch batteries. Always keep both hooked up
I know I argued earlier that you may not need it due to voltage drop, but unless you test it with the TV engine running at various rpms, I would keep the DC2DC charger as otherwise the circuit could draw more than 30 amps and blow the TV fuse.
So, when do you start buying and installing components?
David
A new commandment: "Thou shalt not connect in reverse polarity."
I guess the idea of the 1-2 switch would be to have the ability to independently measure the voltages of both batteries. This would be done to make sure that they were at the same voltage. If they are connected together, then you can't measure the voltage independently of each other unless you manually disconnect them. I was hoping to avoid that if I could.
Yes... my system has MC4 connectors, and I've been using connectors such as you have linked to gang the inputs together. I've recently learned that there is a limit to the current that can go through them, but I've even more recently forgotten what the limit actually is. I should be okay with four panels though.
The TV will also serve as another source of power in the event that I'm away from shore power and don't want to (or can't) set up solar panels. I think that I still need the DC2DC to compensate for voltage drop on the 10AWG cable from the TV, so that I know that I'm getting at least 14.4V to the lithium batteries. I don't think that they would charge much with just 13V. The DC2DC will also moderate the amount of current that is being sucked in from the alternator to the low resistance lithium batteries.
I like data too, and may ultimately move to the Victron battery monitor. Right now, I have an amp-hour/battery meter that seems to work, so I'll stick with it. Do the small buttons on the BMV-702 ever wear out?
The sleep mode is not just with Battle Borns... I think that it may be with other lithium batteries as well. I think that the idea is to prevent over-discharge. Getting back out of it is a problem, because the BMS may keep any voltage from appearing at the battery terminals. Any "auto-sensing" 12/24V charger won't see any charge and will think that it is not connected to anything. Therefore, it's sometimes necessary to present another source of 12V to dupe the charger into thinking that it is actually connected to a 12V battery.
The AC2DC supplies 45A, but the DC2DC that I'm looking at only does 18A. I think that I'll stick with a direct connection to that and get faster charging. Also, that means that my DC2DC won't be on to broadcast BT... I wish there was a way to turn BT off when I wasn't using it on this device. If it weren't for these things, I would consider routing all DC power through the DC2DC.
I wonder about the 14.6V output on the Progressive Dynamic devices. I seem to recall that the max input for Battle Born lithium battery charging is 14.7V, which seems too close for comfort. However Battle Born actually refers to Progress Dynamics products as being compatible for lithium charging. Older lithium batteries operated around 12.8V... I think that this is what the Renogy Rover has as a "default" lithium absorption voltage.
I just ordered the Orion 18A and the BlueSolar 50A. From what Merlin said, I know that the 30A would have been good enough for 4 solar panels, but decided that it would be good to have the option for more than 4 panels in the future. I also got the dongle for the BlueSolar, so that I can "plug in" bluetooth when I wanted to use it. The BMV702 (or the MPPT Control Unit) may be a good option in the future if I want to see data without using bluetooth.
The 2-stage AC2DC has been ordered, and I already have the batteries. Now I need to figure out circuit breakers/fuses, cables, crimps, switch, and undoubtedly other things that I'm missing.
Merlin had recommended this https://www.amazon.com/Blue-Sea-Systems-Circuit-Breakers/dp/B000KOVBXQ/ref=sr_1_8?crid=QXQ1VWTL4TEY&keywords=30a+dc+circuit+breaker&qid=1648430723&sprefix=30A+dc+c%2Caps%2C95&sr=8-8 (https://www.amazon.com/Blue-Sea-Systems-Circuit-Breakers/dp/B000KOVBXQ/ref=sr_1_8?crid=QXQ1VWTL4TEY&keywords=30a+dc+circuit+breaker&qid=1648430723&sprefix=30A+dc+c%2Caps%2C95&sr=8-8)
but I am wondering how it compares with this https://www.amazon.com/Blue-Sea-Systems-Circuit-Breakers/dp/B0055MV7AA/ref=sr_1_2?crid=2TF2GI8078DQP&keywords=Blue%2BSea%2BSystems%2B7035%2B187%2BSeries&qid=1648596090&sprefix=blue%2Bsea%2Bsystems%2B7035%2B187%2Bseries%2Caps%2C85&sr=8-2&th=1 (https://www.amazon.com/Blue-Sea-Systems-Circuit-Breakers/dp/B0055MV7AA/ref=sr_1_2?crid=2TF2GI8078DQP&keywords=Blue%2BSea%2BSystems%2B7035%2B187%2BSeries&qid=1648596090&sprefix=blue%2Bsea%2Bsystems%2B7035%2B187%2Bseries%2Caps%2C85&sr=8-2&th=1). Both are described as being "Blue Sea Systems 7035 187 Series", but the picture and cost are different.
I heard back again from the Victron user group. They didn't clarify on the solar panels, but did suggest that it was not necessary to have protection on the input to the DC2DC. They also said that protection on the output would not be a bad idea, and recommended that it be sized to the DC2DC (with a little buffer). They mentioned fuses though. When I asked about this in the past, they recommended MEGA fuses instead of circuit breakers... ironically, the smallest MEGA fuse that I've seen online is 40A, which seems much higher than what I'd need for the output of an 18A DC2DC.
Thanks to Pinstriper, I have an idea for how to assemble an aluminum battery tray to fit about the wheel wells, using brazing rods that I had already purchased from HFT (I forgot that I had them).
Thanks for Merilin and David as well. I'm sure that I'll still have questions though. I'll be sure to post pictures when everything is installed. This may be awhile though!
Awesome stuff. I think you're headed toward a great system. Good work. For your latest questions:
Multi-stranded cable just means the strands are made up of strands. It's very easy to work with wire and the larger gauges are ofter referred to as welding cable.
I don't think you need a fuse on the input side of the Orion DC-DC.
The important thing is have a breaker that prevents overcurrent from starting a fire if there is a device failure. Having a small capacity breaker on big wire is ok. The other way around is not.
Disconnecting panels under load with a fuse can cause a spark large enough to melt things. A DC breaker is better if you want to disconnect from the MPPT under load. In fact, this summer I'm going to replace a fuse box with a breaker box at the solar array at my cabin. I don't want someone else to pull a fuse with lots of amps running around.
I see I was wrong (first time ever) about the Battle Born batteries not liking 14.6A charging. That is their upper limit for bulk charging so you should be ok with your new PD AC-DC converter.
If you fully charge the batteries independently to exactly the same voltage and then connect them in parallel, they will work together as one battery and you never need to independently check them.
I have used both of the breakers you have linked to. Your choice!
If you use MEGA fuses, you will also need switches. I used MEGA fuses in my very first wind power installation and found they took up a lot of space and added complexity by needing switches too. The main advantage is they are cheap compared to CBs.
The Victron charge controller I use says in the specs it will wake up even 0V batteries. That may not be the case with the one you have?
I'm looking forward to learning from you about how this all works and what installation/design issues come up. Go for it!
Sorry for not responding for awhile... I've been ordering and receiving stuff. Had I known that this thread would contain this much insight on batteries and everything else, I would have chosen a different "subject" for the initial entry. We're way beyond bluetooth now....
I still have some things to consider, and am hoping that folks can provide insight. But first I'll address Merlin's question.
Quote from: Merlin on March 30, 2022, 05:20:10 PM
The Victron charge controller I use says in the specs it will wake up even 0V batteries. That may not be the case with the one you have?
The SmartSolar datasheet mentions a "Fully discharged battery recovery function". The BlueSolar datasheet does not. I've tried to verify this through the Victron user's group, but was not able to get a conclusive answer. I'd like to think that the BlueSolar supports "reactivating" a "sleeping" lithium battery, but I guess that I won't know until (heaven forbid) my batteries do actually get discharged to that point.
I'm been scratching my head with another question... if I have the a positive bus bar with different size cables connected to it, including big beefy cables to the battery, big beefy cables to the inverter, and not as beefy cables to everything else (chargers, controllers, DC loads), then how do I size the amperage of the circuit breaker that is connected to the battery? If I pick a big one that will accommodate the current to the inverter, then it may be too big for the other cables connected to the bus bar.
For example, let's say that the battery and inverter are connected to the bus bar via 4AWG cable, and the battery has a 80A circuit breaker. Cables to the chargers, controllers, DC loads are 8AWG. (See attached cables, breakers and bears... oh my!). If the cable to the solar controller shorts out somewhere between the bus and any other breakers/fuses that I may have for the controller, then this cable may overheat if the current is above the rating for 8AWG cable, but lower than the 80A necessary to trip the breaker at the battery.
I'm wondering if I should not consider attaching the inverter to the bus bar at all, and use a smaller breaker (e.g. 50A) to protect the other cables/devices. If I add an inverter in the future, then I'd have a direct connection to the batteries via 4AWG cable with its own 80A circuit breaker.
Here's another silly question... will a breaker trip if the amount of current exceeds the rated amount
in either direction? For example, if I have a 30A breaker next to a battery because I think that the loads won't exceed 30A, will the breaker switch if I get 40A of current from a charger into the controller?
Any recommendations for bus bars? I'm currently looking at https://www.amazon.com/AMRB-2126-Blue-Sea-MaxiBus-250/dp/B07BS1L8LG/ref=sr_1_18?crid=1Y1YO1M2OQB9&keywords=blue+sea+bus&qid=1648863102&sprefix=blue+sea+bus%2Caps%2C78&sr=8-18 (https://www.amazon.com/AMRB-2126-Blue-Sea-MaxiBus-250/dp/B07BS1L8LG/ref=sr_1_18?crid=1Y1YO1M2OQB9&keywords=blue+sea+bus&qid=1648863102&sprefix=blue+sea+bus%2Caps%2C78&sr=8-18) and https://www.victronenergy.com/dc-distribution-systems/busbars (https://www.victronenergy.com/dc-distribution-systems/busbars). Ideally, I'd need something that would have 6 posts, unless I could put more than one high-current connection per post.
Finally, any recommendations for test ammeters? I am using the built-in capability of my multimeter that goes to 30A, but I'm looking for something that will do at least 100A. I suspect that this will be a clamp meter. Are any made in the US?
Although I've not purchased a Renogy controller or battery, they do have a chart that comes in quite handy when considering wire gauge and fuse sizes. I've attached it as well.
Like I said in an earlier post, I would size all wires to and from the buss (except for the inverter) as 8 gauge and protect that with a single 75/80 amp breaker. That way you do not need the yellow breakers serving each individual service.
FWIW the maximum current table that you posted above is from the NEC and is for AC building wiring. Actual ampacity data is much higher and I suspect the NEC table downrates it for multiple wires packed in a conduit. If you want to follow the NEC requirements then increase the wire size to #6.
If you will PM me your email address I will send you a comprehensive wire sizing program that includes ampacity tables. It takes a bit of Windows skill to install it as it is very old and doesn't have a self installer. Download all of its files and put them in a Windows/Program/Wiresizer folder. Then set up a link to the .exe file in the Windows start page.
Wire the positive lead to the inverter directly from the + battery terminal through an appropriate sized fuse. For a 1,000 watt inverter located 10' from the batteries, #4 wire should work but go with #2 if farther, protected with a 100A fuse. You should wire the negative lead to the buss so the inverter's current will be picked up by the shunt.
Yes breakers and fuses will trip or blow no matter which direction the current is flowing.
The 6 position buss bar looks fine.
I think all DC clamp on ammeters are made in China except perhaps for the expensive Fluke's and I am not even sure about those. Chinese brands come and go on Amazon but the Klein Tools brand has been around a while. Longevity means at least people are buying them over time, right. I used a friend's Klein tools ammeter once, and I wasn't impressed by its ability to hold its zero. But you might have to pay $300 for a Fluke to do better. Make sure that the meter reads both AC and DC current. Many try to fake you out by saying AC/DC in the title but the fine print says AC current only.
David
David did his usual great job on the questions. My only addition would be to ask about the need for a bus bar. I don't know where all the equipment will be located, but if it's all in the same space as the batteries, just connect everything to their posts?
Also, I don't own a separate meter for DC amps. I get amp in/out readings from monitors in the equipment. All my stand-along electrical testing stuff is Klein which my dad (professor of EE) recommended as ok mid-quality equipment that doesn't require a second mortgage to buy.
Edit: I forgot to add that I've used the West Marine wire sizing guide for 12VDC circuitry.
https://www.westmarine.com/WestAdvisor/Marine-Wire-Size-And-Ampacity
If you connected everything to the battery posts, at least for the positives where would you put the breaker? You could use a battery post but that means removing all circuits if you want to use my screwdriver method switching them off. With the buss you can easily remove one without affecting the others.
You can't do it on the negative battery post either because you need to tie the shunt there. You could tie all of the negatives to the shunt terminal upstream of the battery though. That means you only need one buss which makes sense if room is tight.
I noticed that WM's ampacity table is the full wire ratings, not the reduced NEC ones. Their chart is great for normal use: most circuits are either voltage drop sensitive and you should use 3% for those. Others aren't so 10% is fine. My Wiresizer program calculates it exactly based on circuit length and current.
I tried attaching the Wiresizer program to this post. The .exe file is only 80 kB and the 7 data files are small-another 10 kB, but the system wouldn't accept them all.
David
Well, I got the .exe file and one of the data files attached by individually attaching and modifying the previous post, but after two files it locked me out.
David
I put the .exe and .dat files into a folder named Wiresizer within c:/programs. The exe seemed to execute, but gave me an error message "wiresz31 file not found". I suspect that it is looking additional DAT files (which appear to be simple text files).
Thanks for the suggestions, but I like the idea of connecting to a bus. Right now, everything is connected to one terminal, and it is difficult to work with. I will probably mount the equipment on a vertical board, with the components (switch, circuit breaker, solar controller, DCDC) on one side of the board, and with wires and buses on the other side. The components will be accessible from inside a kitchen cabinet (which has a door on it). The wiring will be on the opposite side, which is where the AC2DC currently sits. I suspect that I'll have problems accommodating everything on one side of the board, especially when considering the bend radius of the thicker cables. The downside with this approach is that it won't be easy to get to the buses in order to disconnect things with David's screwdriver. The upside is that it will minimize the number of exposed connections, and cable runs will be very short (less than 5' in one direction).
I'll probably use 8AWG cable, as David recommends, with a separate 4AWG cable (with its own fuse) to my 750W inverter if/when I add it. I'll be sure to connect the negative to the shunt.
For the 8AWG cable, I'm wondering if I really need 75A/80A of protection. Without an inverter, I can't imagine current draws over 50A. My AC2DC can only charge at 45A, the DC2DC can only charge at around 20A, and the solar controller (with 4 solar panels) can only charge at 30A. If only one is charging at a time, then the max would be 45A. However, the 75A would definitely be needed in the unlikely situation that I was connected to shore power and solar panels at the same time (I manually position my solar panels now, and really only do this when I'm at a primitive site that does not have shore power).
Thanks for the heads-up about AC/DC ammeters. I see now that some of them have AC/DC in the title, but that is for measuring voltage... many of the cheaper ones only measure AC amperage. I didn't notice that before.
The OP Tom and I have struggled to upload the Wiresizer program to him by email. I just tried downloading the executable .exe file I uploaded a few days ago and holy s&%$ it works. So I have uploaded the other .dat files to this post that are required to make it work. Combine the .exe file and the .dat file in the above post with these additional six files in one folder and hold your breath and double click on the .exe file. It should open.
I just tried it and IT WORKS, HURRAY!
David
It is working for me too! I copied all of the files into c:/Program Files/Wiresizer, and then put a link to the .exe file on me desktop. Although it seems like the files can be located anywhere, just as long as all of the files are in the same folder. Thanks Dave!
You might also want to spend some time looking at info on line about good cable connectors as someone suggested. A standard hand crimper for wiring sizes greater than 14 or 12 gauge may be problematic. Last time I wired a vehicle for towing I used dual 10 gauge wiring in parallel (it ended up being cheaper this way) and used a Harbor Freight hydraulic connector crimper ($40 at the time) for secure connections. I have used it since for other battery and ground connection (4 - 8 gauge wiring) and it did a good job for infrequent use.
Cable crimping tools seem to come in two size ranges: 18-10 and 8-1/0. Since it looks like all of your work will be in the larger size, get one for about $35 on Amazon. If you ever need a 2/0 or 4/0 go to an auto parts store. They can usually make one up for you.
David
Thanks. I just bought a hydraulic crimper at HFT for $70... but I haven't opened it yet. I'm debating whether I should return it.
I've been looking into breakers. There are a lot of cheap ones out there. I'm assuming that Buss breakers from Blue Seas are quality stuff.
- Any thoughts on the 187 Series versus the 285 series? Both are available in panel mount and surface mount. However, he 285 series seems to be a little smaller and less expensive.
- The 285 series is rated at 3000A at 48V (higher than the 1500A rating for the 187 series), but do not have an amperage rating for 12-14VDC. Can I still use them for 12-14VDC?
BatteryCableUsa seems to have different types of stranded cable. David... thanks for the recommendation. They have a "rubber welding cable" (https://www.batterycablesusa.com /welding-cable-rubber-battery-cable (https://www.batterycablesusa.com%20/welding-cable-rubber-battery-cable)) that is touted for "tight spaces". I have tight spaces! However, this cable type is only available for 6AWG to 2/0AWG.
- Given that I would like to use 8AWG, should I use the "Battery Cable Flexible" (https://www.batterycablesusa.com/UL-flexible-multi-rated (https://www.batterycablesusa.com/UL-flexible-multi-rated)) instead? I'm hoping to get a 1" or less bend radius if possible.
I've been looking at crimps (wire lugs?). Most of what I need will be 8AWG, with either a 5/16"or 1/4" ring.
- Should I get tinned copper or just plain copper? Since this is not a boat, I'm thinking that plain copper is fine.
- I notice that some crimps have a flare at the bottom of the collar... but these tend to be for larger wire gauges (2AWG). Is a flare important for 8AWG?
- BatteryCableUse sells tinned crimps that are flared but this is by the piece. I'm wondering if I should get an assortment of crimps that are plain copper without the flare... any thoughts?
The very flexible cable has many more fine strands which makes it flexible. Never used it except for battery jumping but it should work fine although it is not tinned.
For ring crimps, the only advice I can give is don't use the short ones with short insulation. A longer one gives more latitude as to where to crimp and the insulation extends beyond the metal for better insulation protection.
Never used a hydraulic crimper. Sounds like an extravagance. A simple jointed mechanical one that multiplies the leverage should work fine for 6 or 8 gauge. For 10 gauge and under I use a simple pliers type.
You might try searching further for cable. Maybe places like Harbor Freight sell it.
David
Although I admit I've paid premium prices by ordering wire and crimps from a solar supply company, I decided the peace of mind getting good stuff was worth it. This place sells wire that's just right for the kind of work you're doing, as well as crimps and connectors.
https://www.solar-electric.com/search/?q=Cable+%238
I have always used the 187 Blue Seas breakers because they also are easy to operate switches.
Like David, I've used jointed mechanical crimping tools for big wire up to 8 gauge and simple plier crimpers for tiny stuff up to 16 gauge. For the big wires like 00 or even 4/0 to inverters I've custom ordered the cable with lugs crimped. Note that auto supply stores sell 4 gauge lugged battery cables in a wide variety of lengths ready to go.
The flare on a crimp is irrelevant to the connection, it just makes it easier to get the lug over the wire stands.
Thanks for all of the good info. Can I purchase "bare" ring crimps and use my own shrink tubing, and make the insulation as long as I like?
I've decided to reduce the number of switches, fuses and breakers so that I can fit everything on one side of the board. I'll be using one 80A series 187 breaker, 8AWG regular "flexible" (MTW/THW/SGT) cable, 2 6-post terminals, and my existing shunt. I'll probably get the cable from Batterycablesusa.com or Solar-Electric and then get copper wire lugs (without the flare on the bottom) there or from amazon. I've checked, and Harbor Freight doesn't sell that type of cable. I'll wait until later to add the inverter, in which case I'll use separate 6AWG cable.
I discovered that I live around 1/2 hour from https://shop.pkys.com/ (https://shop.pkys.com/) . It seems that their prices are comparable to amazon, and in some cases lower. It should be fun to browse as well. Most of the inventory is for maritime applications (in Annapolis MD), so they only have tinned cable and lugs, but I think that I'll be able to save some on the bus bars. Unfortunately, the bus bars don't have covers. I'm thinking of making something using the 3D printer at the public library (another fun project for later).
Wow, I knew Peter Kennedy in Annapolis some 23 years ago. He recommended and sold me a Balmar regulator I was upgrading my new sailboat alternator with. Looks like his business is doing well.
David
Based on the good info that I got from this thread, I made some purchases for a lithium battery upgrade... including a solar controller, DC-DC converter, and other items. I recently began to install the equipment, and started a new thread at Lithium Battery Upgrade (https://aluminumcamperforum.com/index.php?topic=1628.0).
Thanks to all who helped so far!