Does bluetooth work in an aluminum camper? Victron vs. Renogy

[RV Squirrel]

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!

[DavidM]

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

[Merlin]

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. 

[RV Squirrel]

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.

[Pinstriper]

See "Cage, Farraday"

[DavidM]

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

[RV Squirrel]

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.

[Merlin]

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.

[RV Squirrel]

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.

[DavidM]

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

[Merlin]

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!

[DavidM]

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

[RV Squirrel]

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.

[DavidM]

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

[Merlin]

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.