Aluminum Camper Forum

Camping => Boondocking => Topic started by: tbrady on February 14, 2017, 02:57:29 PM

Title: 2 -(6v) batteries vs 2 (12v) batteries
Post by: tbrady on February 14, 2017, 02:57:29 PM
Hi All,

I asked my dealer about getting a trailer with 2 6 volt batteries instead of a single 12 volt battery.  They spoke to Livin Lite and apparently Livin Lite recommended going with 2 12v batteries instead, something about how hot the wires can get with 6v batteries as one battery drains down.

Does anyone know anything about this or have any recommendations?  From everything I have read online it seems going with 2 6v batteries is better...

Thoughts??
thanks
tim
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on February 14, 2017, 03:11:25 PM
That is pure BS from Livin LIte. What is the difference between one 12V battery where all cells are internally connected and two 6V batteries where one set of cells is connected to the other set with a wire.

Now certainly you have to use a big enough cable to connect the two  batteries, but #6 is good enough, but many use bigger. You can buy short 1' long interconnecting cables at any marine store.

And if you have the room and the capacity for the weight, two 6V batteries give you true deep cycle capability. Most 12V batteries are not true deep cycle and make compromises in their construction to be so called dual purpose.

And because they are used everywhere there is a golf course, 6V batteries are relatively cheap and give you the most bang for the buck.

The only reason to use a single 12V battery is tongue weight. A single Group 27 12V battery weighs about 60 lbs and a pair of 6V batteries weighs 140 lbs.

David
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: charliem on February 14, 2017, 05:53:14 PM
To second DavidM: (..pure BS from LivinLite)2. Either they misunderstood or MaryJane has come to IN. Technically two 6V batteries in series are better than two 12s because all cells are in series. Batteries like series vs parallel. Go golfers.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: pjcd on February 14, 2017, 07:14:53 PM
What are the cost differences?
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Merlin on February 14, 2017, 08:39:01 PM
Quote from: pjcd on February 14, 2017, 07:14:53 PM
What are the cost differences?

If you compare "apples to apple" there isn't a cost savings between two 6 volt batteries in series and two 12 volt batteries in parallel. However, because flooded cell 6 volt GC2 golf cart batteries are so common and readily available, you can get them relatively very inexpensively. So they win hands down in the cost contest.

For example if you stick with real deep cycle batteries in a good brand like Crown or Lifeline, buying two 6 volt batteries will set you back as much as two 12 volt batteries, assuming the same total amp-hour capacity for each pair. As David noted above, the problem is finding real, honest, deep cycle 12 volt batteries for the comparison. And, those are spendy.

A PAIR of 6 volt GC2 batteries from a warehouse store like a Sams Club will set you back only $170. A bargain for the power available.

I think a real bargain in RV batteries is the Duracell 6VDC AGM GC2 golf cart battery available at Sam's Club for $180 each. I like AGM in an RV setting because there is no venting of corrosive gases and no maintenance. Not incidentally, two of the same brand/type of battery in 12VDC cost the same at Sams Club, so price is a wash. However, in this case the 6VDC are deep cycle and the 12VDC is dual purpose, so not true deep cycle. The 12VDC will work fine, but may not last as long deeply cycled.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: pjcd on February 14, 2017, 11:12:46 PM
As they say.......................
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: gbpack on February 15, 2017, 08:20:21 AM
Our two golf cart 6-volt car batteries from Costco were $105 each (including tax). As mentioned, golf cart batteries are deep cycle and work great wired together in series. Last summer we camped for 4 nights with no hook-ups and our batteries were still at 50% state of charge. I highly recommend doing it that way!
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on February 15, 2017, 10:37:17 AM
Let me use this thread to comment on AGM (absorbed glass matt) batteries discussed above vs more conventional flooded cell batteries. AGMs are a newish type of self contained, non venting battery capable of being mounted upside down if necessary. They are made in all sizes. Flooded cell batteries are the kind that have been around for centuries and deep cycle batteries have fill caps for adding water when necessary.

AGM Pros:

Don't require checking and adding water. This is almost a non issue for me as I check a couple of times each summer and usually add water once each year to my flooded cell batteries.

Don't offgas. Well I am not sure that this is true, but in any case it is irrelevant for batteries mounted in the open air on your trailer's tongue.

AGMs have both deep cycle and starting battery properties and there is very little difference between AGMs sold for each type of use.

Some believe that AGMs can be discharged more deeply than flooded cells without harm. I haven't seen any data to support this, but it is a pervasive view on the various boater forums.

AGMs can supply huge amounts of current when necessary and can be recharged at a higher rate than flooded cell batteries. The supply advantage is irrelevant for RV use as the typical current draw is very low. The recharge advantage has some value, particularly if you only use one battery. A single Group 27 battery has 60-70 amp hours of capacity and the normal 40 amp converter can recharge a flooded cell too fast. But a pair of 6v flooded cell golf cart batteries has enough capacity to deal with the 40 amp converter.

Cons:

Cost. AGMs cost 2-3 times more than flooded cell batteries.

So if you are willing to pay more, you can forget about checking and adding water. Otherwise there is little advantage to AGMs over a pair of 6V golf cart batteries.

David
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: charliem on February 15, 2017, 11:14:33 AM
Quote from: DavidM on February 15, 2017, 10:37:17 AM

So if you are willing to pay more, you can forget about checking and adding water. Otherwise there is little advantage to AGMs over a pair of 6V golf cart batteries.

David
I totally agree with DavidM's comments. I've never really understood the attraction of AGMs for the average camper. If the batteries are conventionally mounted on the tongue and you're willing to check the water level occasionally there's absolutely no advantage to AGMs except a much lighter wallet after leaving the store. Camp on!
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: GoElectric on February 15, 2017, 11:58:21 AM
The only way it will reduce the heat in the wires with two 12 volt batteries, is connecting them in series for 24V with half of the current as is done in a bass boat, which obviously won't work on the 12 volt system.  We are using two 6 volt golf cart batteries because we like to camp at National Forest Campgrounds, which many restrict generator use, and the 6 volt's work great.  Also, for the benefit of the extra tongue weight when tanks are low or empty, because we have the rear deck option and when loaded really lightens the tongue weight too much.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: tbrady on February 15, 2017, 12:13:47 PM
Thanks for all the great information everyone!
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: tinkeringtechie on February 15, 2017, 01:33:22 PM
Another advantage of AGM's that could be useful for certain campers is their low self-discharge rate. A typical FLA battery has a self discharge rate of 5-10% per month, but an AGM battery is 1-3% per month. That could be helpful for solar charging or some storage situations.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: catmanriff on February 16, 2017, 12:48:08 AM
I'm gettin' my learnin' on with these posts!

Thanks
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: charliem on February 16, 2017, 09:39:36 AM
 It's been addressed before but it's worth repeating here: If you plan on boondocking and you have a 6 cu ft two door fridge you must disable the frame heater. The two door Dometic refrigerator has an electric frame heater the sucks 0.5 Amps from the battery 24/7. This results in an automatic 12 AH draw every day that cannot be turned off.

To put this in perspective the average daily use while boondocking has been estimated at 15-30 AH/day depending on furnace use. If you add the constant frame heater draw you bump that up to 27-42 AH/day. That significantly reduces the number of days you can stay out with no real benefit. Using 15AH/day and 110AH allowable (50% of 220AH available with two GC2 golfers) your boondocking would be reduced from 7 days to 4 days. Search the archives of this forum for "frame heater" (without quotes) for details of the simple mod. 
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: pjcd on February 16, 2017, 10:56:11 AM
How do you disable the frame heater? Is there a fuse or switch?
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: charliem on February 16, 2017, 11:03:42 AM
No switch or fuse. Dometic used to provide a switch but it was deemed too confusing for the average consumer, and with energy "free", they deleted it and saved themselves 37 cents. The mod involves disconnecting a certain blue wire at the back of the fridge. If you want the option of using or not using the frame heater you have to add a toggle switch. Search the archive for posts on the subject from me an TinkeringTechie. If you still need help I can repost the mod if I can find it.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: charliem on February 16, 2017, 11:19:24 AM
The original work on the fridge frame heater was done when LL was installing the 7 cu ft Dometic model 3762 . Currently LL advertises a 6 cu ft fridge, model and mfgr unknown. Can someone with a new CL post the current fridge info?
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on February 16, 2017, 11:34:44 AM
Quote from: catmanriff on February 16, 2017, 12:48:08 AM
I'm gettin' my learnin' on with these posts!

This has been an interesting and meaningful thread: An operational problem discussed, good solutions given and understanding improved. I doubt that you will see that on the new LL forum!

Keep it up, folks.

David
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: tbrady on February 16, 2017, 01:58:54 PM

What is the purpose of the frame heater?  And thanks for the great information!! I do a ton of boondocking and this will help a ton.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: tinkeringtechie on February 16, 2017, 02:39:54 PM
Here's a pic of the wire in question (light blue):

(http://i.imgur.com/Bu51gfh.jpg)

Not sure if it's always the same color, but you can also notice that it's "ribbed" not smooth like the others. That's because it's a giant spiral of NiCr wire. I just removed it from the post and put some heat shrink on the end. Never needed to turn it on again and never had issues with frost or condensation.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Steve and Dana on February 16, 2017, 03:57:31 PM
Here is the manual for the 6 cubic foot unit

https://www.livinlite.com/forum/index.php?action=dlattach;topic=26.0;attach=42
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: charliem on February 16, 2017, 05:41:35 PM
Quote from: Steve and Dana on February 16, 2017, 03:57:31 PM
Here is the manual for the 6 cubic foot unit

https://www.livinlite.com/forum/index.php?action=dlattach;topic=26.0;attach=42 (https://www.livinlite.com/forum/index.php?action=dlattach;topic=26.0;attach=42)
Your link requires logging into the LL forum. Not all of us are members. You'll have to post a different link so we can read it.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Steve and Dana on February 16, 2017, 08:02:20 PM
Sorry, forgot that a sign on was needed.  Still check the other forum occasionally to see what is new.  This should work better.....

https://www.campingworld.com/includes/productSpecs/Dometic%20Americana%20RM2852%202-Way%20Refrigerator,%20Double%20Door,%208.0%20Cu.%20Ft.%20users%20manual.pdf
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: charliem on February 16, 2017, 09:34:43 PM
STEVE AND DANA: Thanks for the link to the fridge manual.

Although not yet confirmed, I'm guessing the newer CLs are shipping with the Dometic RM 2662. The book indicates the Climate Control system can be disabled by a switch. If so, no mod is necessary; just turn it off. The purpose of the Climate Control system is to prevent condensation from forming on the exterior in wet climates. That's caused by poor insulation used in an attempt to wrest more inside volume from a fixed outside volume. Condensation is rarely a problem and can be easily wiped off it it forms. With an easily accessible switch the CC can be turned on when shore power is available. 
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Steve and Dana on February 17, 2017, 08:22:09 AM
No problem.  I am sure that there are others that have questions relating to items installed in or on their TT's.  I am not trying to lobby for the other forum, but Dan Miller has compiled quite an extensive listing of manuals for components that Livinlite has used in the construction of their trailers.  Some may want to have a sign on account just to gather information on these manuals.  The appliance section has, by far, the most comprehensive listing of items installed.

Steve
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Steve and Dana on February 17, 2017, 08:56:21 AM
Made the attachement too small
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Chappy133 on March 25, 2017, 08:08:34 PM
Had a 60 degree day installed our two Trojan 6 volt batteries today. Had to remove the factory battery set up. The quick box dual battery case is wider than the factory box. This meant the LP tanks had to move forward but not too far forward to impede the jack crank. Had to fabricate bar stock to support the new battery box.  First trip of the 2017 is next weekend. Happy Trails!
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: gbpack on March 25, 2017, 09:53:31 PM
Nice job Chappy. You will like that set-up and get very good performance out of it!
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Merlin on March 25, 2017, 11:35:20 PM
Great! What's the separate fused small wire running into the battery box in the front?
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Chappy133 on March 26, 2017, 12:16:22 PM
Yeah I forgot to mention that. It is connection for our 80W solar panel. 
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on March 26, 2017, 01:39:53 PM
Can you tell us about your solar panel: controller, how mounted or is it portable, how much cable if portable? How did you deal with the controller being outside presumably? Most aren't waterproof.

David
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Chappy133 on March 26, 2017, 04:26:43 PM
Our 80 watt panel, has a controller on the back of the panel, is made or better said assembled my a company that is no longer in business.  Portable with legs that allows adjusting the angle. It has a 15' cable plus a 25' extension. We bought it for our 6.0'camper a few years back.  If I were to buy now I would get a panel in the 100 -120 watt range as a minimum. The 80w panel has kept our 12v battery charged on trips lasting a week.  Lots RV solar solutions are out there. I liked ours because it was a complete package.

You will be able to see the complete set up in Maine this summer at the get together.

I do not have a good pictures of the panel.  I make a point of getting some in the future.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on March 26, 2017, 04:44:02 PM
Thanks for the info on your solar panel. Some years ago I had a solar panel laid up on top of our boat with the controller mounted underneath it, perhaps like yours. It was a Morningstar Sunsaver PWM controller. It worked fine for a year or so, but finally died possibly from rain water blowing under the panel or maybe just marine humidity.

I switched to a Morningstar Sunkeeper controller which is potted in epoxy so it is totally waterproof. I doesn't have the features of the other one, particularly the ability to switch battery types, because that would have required moisture vulnerable switches. But it has been going strong for a couple of years now.

If anyone wants to build a solar panel from components and wants to mount the controller outside, this is the waterproof controller I would use: https://www.amazon.com/Morningstar-SK-12-SunKeeper-Charge-Controller/dp/B007NYZ5VU/ref=sr_1_2?ie=UTF8&qid=1490556931&sr=8-2&keywords=morningstar+sunkeeper+charge+controller

You could mount your controller in your new battery box to protect it. That would also shorten up the leads from the controller to the battery which is critical for best performance.

David
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Chappy133 on April 15, 2017, 11:52:51 AM
 ECO-WORTHY 12 Volts 120 Watts Portable Folding Monocrystalline Solar Suitcase with Charge Controller https://www.amazon.com/dp/B01M4NH9ES/ref=cm_sw_r_cp_tai_lFI8ybNC1SJD5 

Good price.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: tbrady on April 24, 2017, 12:47:22 PM
Can someone confirm these numbers? 

Our current single 12V battery has a rating of 70 @20amps/hr or something like that.  With only half being available that gives us 35amps/hr of available battery before we need to recharge?

If I buy 2 of the Duracell GC2 batteries which are rated for 205 amps each we would have 205 amps of available power, almost 6X as much as a single 12 volt?

Is that correct??
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on April 24, 2017, 02:43:58 PM
No, when you wire two 6V batteries in series to make 12V, you do not double the amp hours. They stay the same but the voltage doubles. So you have about 110 AHs useable. about triple the single 12V battery.

David
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: tbrady on April 24, 2017, 03:14:32 PM
Doh!  Thanks for the correction David.  I knew that sounded too good to be true!
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: thedusty on June 13, 2017, 06:10:43 PM
Quote from: gbpack on February 15, 2017, 08:20:21 AM
Our two golf cart 6-volt car batteries from Costco were $105 each (including tax). As mentioned, golf cart batteries are deep cycle and work great wired together in series. Last summer we camped for 4 nights with no hook-ups and our batteries were still at 50% state of charge. I highly recommend doing it that way!
Would you mind sharing which exact model you bought?  I might be copying you.

I also have a 100w solar panel but need to figure out the charge controller situation and how it links into the Zamp exterior outlet on the side.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: gbpack on June 13, 2017, 07:06:49 PM
Dusty - Our camper is in storage right now, so I don't know the exact model, etc. right offhand. I remember that we bought them at Costco and that they are made by Interstate. They didn't have any other 6-volt golf cart batteries to choose from, so we just took those. I think they are rated for 110 amp hours, but would have to look at them to be certain. I'm sure that whatever they have at the Costco nearest you would be similar and work well for you.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on June 13, 2017, 07:15:54 PM
Batteries Plus Bulbs also sells 6V golf cart batteries at reasonable prices, about $100 ea. There are two slightly different models: GC1 and GC2. The GC2 has a slightly higher amp hour rating.

I haven't looked at a LL with the Zamp connector, but I can guess what it is:

It is a "female" connector recessed into the side of the outside wall. I say female only because it is recessed. The Zamp connector is unpolarized and has a female and a male connector that a male and female connector of the same type plugs into. AFAIK, the Zamp connector is generic and you can buy the plugs from Amazon and others for a few bucks. See https://www.amazon.com/dp/B0057ZQJ12/_encoding=UTF8?coliid=I3SWULPLORRIPP&colid=3RQ44LC06SQ2O

I also suspect that from the wall mounted connector the wiring goes to the converter and from there to the battery. So I would look behind the connector and find a place to mount your solar controller inside. Also look at the wire size. If you are just going to hook up a 100 watt panel then the wire which I would guess is 12 or 14 gauge is ok. But any more and I would upgrade the wire size, particularly from the controller to the converter.

Then buy an Amazon plug, cut it in two and wire one to your solar panel making sure that the polarity is correct with a cable as long as you need it, again noting panel size. I would use 12, 14 or 10 gauge SO cable that you can buy from the home stores. It is black and can deal with UV.

David
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: thedusty on June 19, 2017, 03:19:56 PM
Quote from: gbpack on June 13, 2017, 07:06:49 PM
Dusty - Our camper is in storage right now, so I don't know the exact model, etc. right offhand. I remember that we bought them at Costco and that they are made by Interstate. They didn't have any other 6-volt golf cart batteries to choose from, so we just took those. I think they are rated for 110 amp hours, but would have to look at them to be certain. I'm sure that whatever they have at the Costco nearest you would be similar and work well for you.

Did going to two batteries change much in the dynamics for the tongue weight?  It adds another 60lbs it seems. I'm on the verge of doing it but keep second guessing myself.

Also, did you get some solar panels for charging?
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: gbpack on June 19, 2017, 08:44:23 PM
Dusty - We don't notice any changes in towing or handling because if the weight of our two 6-volt GC batteries on the tongue. We have an automatic air suspension leveling system on our Jeep Grand Cherokee and it can handle quite a bit of tongue weight (about 750 pounds if I remember correctly). Also, we don't have a solar charging system as we don't do much boondocking and usually have electric hook-up. However, one time we camped at a State Park for 4 nights with no hook-ups and relied solely on our batteries with no problem whatsoever. After 4 days we still had over 50% state of charge lelft in our batteries. After we left, they charged up a little on the trip home and then finished charging completely when hooked up to shore power at home. I highly recommend going with the 2 GC batteries.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: thedusty on June 20, 2017, 12:36:40 AM
Quote from: gbpack on June 19, 2017, 08:44:23 PM
Dusty - We don't notice any changes in towing or handling because if the weight of our two 6-volt GC batteries on the tongue. We have an automatic air suspension leveling system on our Jeep Grand Cherokee and it can handle quite a bit of tongue weight (about 750 pounds if I remember correctly). Also, we don't have a solar charging system as we don't do much boondocking and usually have electric hook-up. However, one time we camped at a State Park for 4 nights with no hook-ups and relied solely on our batteries with no problem whatsoever. After 4 days we still had over 50% state of charge lelft in our batteries. After we left, they charged up a little on the trip home and then finished charging completely when hooked up to shore power at home. I highly recommend going with the 2 GC batteries.

Thank you.  That's very helpful.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Merlin on June 20, 2017, 10:16:45 AM
Quote from: thedusty on June 13, 2017, 06:10:43 PM
Quote from: gbpack on February 15, 2017, 08:20:21 AM
Our two golf cart 6-volt car batteries from Costco were $105 each (including tax). As mentioned, golf cart batteries are deep cycle and work great wired together in series. Last summer we camped for 4 nights with no hook-ups and our batteries were still at 50% state of charge. I highly recommend doing it that way!
Would you mind sharing which exact model you bought?  I might be copying you.

I also have a 100w solar panel but need to figure out the charge controller situation and how it links into the Zamp exterior outlet on the side.

The golf cart batteries at Costco are stock number 850284, Interstate model    9-GC2-UTL. This forum has converted me from my usual practice of 12 volt batteries in parallel to 6 volt batteries in series. In fact, I just invested a couple thousand dollars in 6 volt (GC2) batteries for the solar charging station I use for my plug-in hybrid car. Great info on this site!

Your Tundra won't notice the extra 60 lbs, if you go with 2 batteries!
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: thedusty on June 20, 2017, 10:45:52 AM
Quote from: Merlin on June 20, 2017, 10:16:45 AM
Quote from: thedusty on June 13, 2017, 06:10:43 PM
Quote from: gbpack on February 15, 2017, 08:20:21 AM
Our two golf cart 6-volt car batteries from Costco were $105 each (including tax). As mentioned, golf cart batteries are deep cycle and work great wired together in series. Last summer we camped for 4 nights with no hook-ups and our batteries were still at 50% state of charge. I highly recommend doing it that way!
Would you mind sharing which exact model you bought?  I might be copying you.

I also have a 100w solar panel but need to figure out the charge controller situation and how it links into the Zamp exterior outlet on the side.

The golf cart batteries at Costco are stock number 850284, Interstate model 9-GC2-UTL. This forum has converted me from my usual practice of 12 volt batteries in parallel to 6 volt batteries in series. In fact, I just invested a couple thousand dollars in 6 volt (GC2) batteries for the solar charging station I use for my plug-in hybrid car. Great info on this site!

Your Tundra won't notice the extra 60 lbs, if you go with 2 batteries!

Thank you! 

Those are the batteries I will be going with then when I pull the trigger.

I'd be curious to hear your thought on charge controllers. I was looking at the MPPT model as a starter model to learn with and pair to a 100w panel I already have.

ECO-WORTHY 20A 12V/24V MPPT Solar Charge Controller Solar Regulator 15-30% More Power https://www.amazon.com/dp/B00FF1KGT4/ref=cm_sw_r_cp_api_GAsszbNA4KQB0


I'm still learning about cable but I was looking at something like this so I can put the panel beyond the trees. 

solar cable 100' Black bulk #10 Copper PV wire with XLPE insulation 1000 VDC https://www.amazon.com/dp/B00IIXJF6G/ref=cm_sw_r_cp_api_4AsszbGSNN42W
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on June 20, 2017, 11:34:01 AM
That 100' roll of 10 gauge cable looks perfect for hooking up your panels.

I am not a fan of cheap Chinese made solar controllers like the one you referenced. A good MPPT controller is expensive, but you would only lose maybe 15-20% if you used a PWM controller.

Morningstar makes good PWM controllers. You will need at least a 10A one like this one for $51.00:

https://www.amazon.com/SunSaver-Charge-Controller-12V-10A/dp/B002MQW3H8/ref=sr_1_4?ie=UTF8&qid=1497969010&sr=8-4&keywords=morningstar+pwm+charge+controller

Or this one if you want to mount it outside as it is waterproof:

https://www.amazon.com/Morningstar-SK-12-SunKeeper-Charge-Controller/dp/B007NYZ5VU/ref=sr_1_12?ie=UTF8&qid=1497969010&sr=8-12&keywords=morningstar+pwm+charge+controller

David
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Merlin on June 20, 2017, 12:13:42 PM
Davidm is right on about charge controllers. The Morningstar PWM controllers he referenced are excellent; I've use one of those for years. I've also used this one (and MPPT controller) for years and have had excellent performance:

https://www.solar-electric.com/mosumpsochco.html

For even more money, you can buy a meter for that charge controller to have fun seeing what's going on:

https://www.solar-electric.com/mormredime.html






Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: thedusty on June 20, 2017, 01:05:19 PM
Quote from: DavidM on June 20, 2017, 11:34:01 AM
That 100' roll of 10 gauge cable looks perfect for hooking up your panels.

I am not a fan of cheap Chinese made solar controllers like the one you referenced. A good MPPT controller is expensive, but you would only lose maybe 15-20% if you used a PWM controller.

Morningstar makes good PWM controllers. You will need at least a 10A one like this one for $51.00:

https://www.amazon.com/SunSaver-Charge-Controller-12V-10A/dp/B002MQW3H8/ref=sr_1_4?ie=UTF8&qid=1497969010&sr=8-4&keywords=morningstar+pwm+charge+controller

Or this one if you want to mount it outside as it is waterproof:

https://www.amazon.com/Morningstar-SK-12-SunKeeper-Charge-Controller/dp/B007NYZ5VU/ref=sr_1_12?ie=UTF8&qid=1497969010&sr=8-12&keywords=morningstar+pwm+charge+controller

David

Thank you.

I'm still learning about panels...would these handle a second 100w panel if I added one?  Which is the best way to determine this when looking at a charge controller...its amp rating?

Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Pinstriper on June 20, 2017, 01:38:32 PM
My head spins whenever I look at this stuff.

Is there a single converter/charge controller that would replace what we currently have, taking AC, DC from the TV, and solar, all driving to a battery bank, and also if connected to shore power drive the AC circuits ?

Or do you have a separate solar controller hooked up directly to the batteries, side by side with the main converter/charger unit we already have ?


Sent from my iPad using Tapatalk
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on June 20, 2017, 03:56:36 PM
thedusty:

You can get close enough to the amperage rating you need for your solar controller if you take wattage and divide it by 12. So for a pair of 100 watt panels, you need a controller with at least an amperage rating of 200/12 = 17 or practically at least 20 amps.

At 200 watts you are at the point where a MPPT controller might make sense. Go to wholesalesolar.com and click on their charge controllers. These like Bluesky, Morningstar, etc are all American designed, Chinese made like most things, but American quality management.

So looking at that site you can find a Midnight Solar PWM controller for $89 or a Blue Sky MPPT controller for $200, both rated for 20A. The extra $111 produces about 30-40 watts more usable power. But if you really only need 160 watts usable, the PWM controller is much cheaper.

David

Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on June 20, 2017, 04:19:35 PM
Pinstriper:

What you describe is fairly routine for boats and some more expensive RVs. This is what it takes:

You need a fairly robust battery bank, at least a pair of golf cart batteries and preferably two pairs if you are going to draw much AC from the system.

That "house bank" as it is called in the boating world, is connected to an inverter/charger, preferably one with a built in transfer switch. Your 120V shorepower is connected to the AC in side of the inverter/charger and the AC out side is connected to your house AC main panel so it can power all of the RVs AC loads.

Then when you are hooked up to the campground's shore power, the transfer switch passes the power through to power the AC loads in your RV. It also powers the charger (just like a converter which you won't need with this system) which charges the batteries.

When you are not hooked up to shore power, the transfer switch automatically switches to inverter generated AC power which then supplies all of the RVs AC loads. You can power a microwave (for 5-10 minutes to warm something up), the TV and have AC at the outlets to plug in a hair dryer (but again not for long), etc. But don't try powering the air conditioner with the inverter. A 12,000 btu A/C requires about 15 amps at 120V which takes 175 amps DC. That will run your two pairs of GC batteries down below 50% in an hour.

To replace all of those amps that the inverter uses you need solar panels and a controller hooked up to the house battery bank. As described in the previous post, you can put a twin 100 watt panel system together for about $400 for panels, controller and wiring.

As far as I know there is not a single package solar controller, inverter and charger. It takes at least two components to do what you want.

That kind of system won't be cheap. $400 for four GC batteries and $400 for a 1,000 watt modified sine wave inverter/charger or $1,000 for a pure sine wave 2,000 watt unit. Plus some heavy wiring.

So most of us just use cigarette lighter plug in inverters that are good for 150 watts AC, or a bit more than an amp at 120V. Good for powering a TV or laptop, but not much else.

David
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Merlin on June 20, 2017, 04:48:18 PM
There are companies that pre-assemble everything needed for you with the charge controller, inverter, charger (converter), switches and generator or shore power input all in one unit. They are, however, very spendy, very large, and very heavy to provide the capacity needed. All these need is to attach the solar panel wires, the battery wires, the shorepower wires, and the house (camper/boat) fuse/breaker panel wires. They handle all the electron traffic. The one below is for a 24 volt battery bank, but can be configured 12 or 48 volt too. And, as noted above, not enough output or storage for air conditioning (don't even think about it).

https://www.solar-electric.com/midnite-mnsw2524-kid-b-schneider-electric-system.html
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Pinstriper on June 20, 2017, 05:56:20 PM
Actually I don't care about the inverter, I have no intention running AC off the batteries - those circuits would only be lit when on shore power.

I just want a single unit that can take input from AC shore power, DC from solar and TV, and both charge batteries and drive DC circuits, plus drive AC circuits while on shore power.


Sent from my iPad using Tapatalk
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: thedusty on June 21, 2017, 03:02:51 PM
Quote from: DavidM on June 20, 2017, 03:56:36 PM
thedusty:

You can get close enough to the amperage rating you need for your solar controller if you take wattage and divide it by 12. So for a pair of 100 watt panels, you need a controller with at least an amperage rating of 200/12 = 17 or practically at least 20 amps.

At 200 watts you are at the point where a MPPT controller might make sense. Go to wholesalesolar.com and click on their charge controllers. These like Bluesky, Morningstar, etc are all American designed, Chinese made like most things, but American quality management.

So looking at that site you can find a Midnight Solar PWM controller for $89 or a Blue Sky MPPT controller for $200, both rated for 20A. The extra $111 produces about 30-40 watts more usable power. But if you really only need 160 watts usable, the PWM controller is much cheaper.

David

Thank you to everyone for all the help.  I've been tied up so I need to sift through it better and read more. 

I'm leaning towards buying the "good" MPPT models mentioned with at least 20A ability with the idea of...buy one, cry once.  I'm leaning towards the MPPT model b/c for whatever reason the idea of losing 20% efficiency angry...though it's not rational...  But neither was spending gobs of money on an all-aluminum travel trailer...  ;-)

I need to look closer and see if any of these MPPT models are waterproof too and could be mounted outside if needed.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: thedusty on June 21, 2017, 04:31:43 PM
Quote from: DavidM on June 20, 2017, 03:56:36 PM
thedusty:

You can get close enough to the amperage rating you need for your solar controller if you take wattage and divide it by 12. So for a pair of 100 watt panels, you need a controller with at least an amperage rating of 200/12 = 17 or practically at least 20 amps.

At 200 watts you are at the point where a MPPT controller might make sense. Go to wholesalesolar.com and click on their charge controllers. These like Bluesky, Morningstar, etc are all American designed, Chinese made like most things, but American quality management.

So looking at that site you can find a Midnight Solar PWM controller for $89 or a Blue Sky MPPT controller for $200, both rated for 20A. The extra $111 produces about 30-40 watts more usable power. But if you really only need 160 watts usable, the PWM controller is much cheaper.

David

I just ordered the Blue Sky model.

https://www.amazon.com/gp/product/B007S1HA2K/ref=ox_sc_act_title_1?smid=A31H76PZNDKUUJ&psc=1

My wife is an exec at Amazon...so I get an earful if I don't order through them.  Ha.

Anywho, do I need an LCD monitor to go with it?  If so, is there a "cheap" version that will do the trick?



Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on June 21, 2017, 05:02:46 PM
That Blue Sky controller should work great. You could even parallel three 100 watt panels and use it with them given the 25A spec.

I wouldn't buy Blue Sky's monitor. Others have installed the Drok battery monitor that Amazon sells for about $30. it gives instantaneous voltage and amperage and cumulative watt hours consumed or added. I am going to install one the next time we go camping and will provide feedback.

David
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Merlin on June 21, 2017, 05:18:10 PM
You don't need a monitor for the controller to work fine, but they are fun. If you want a Blue Sky monitor, you can get a less expensive version than the "Pro". Here's one for $80.

https://www.solar-electric.com/iprediforimo.html

I don't want to rain on Davidm's parade and I've never used a Drok monitor and they may be absolutely fine, but all three things I have purchased under the Drok name either came defective out of the box or failed soon after installation.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on June 21, 2017, 06:42:53 PM
Merln:

It's ok as it is not really my parade. Tinkeringtechie, who now posts on the other LL forum, introduced me to it. Yes, it is Chinese and most Chinese stuff is a POS- see my comments above on Chinese solar controllers. But for $30 I decided to roll the dice. It goes beyond the Blue Sky monitor as it shows cumulative watt hour use/charging input.

David
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: thedusty on June 21, 2017, 06:53:30 PM
Quote from: DavidM on June 21, 2017, 05:02:46 PM
That Blue Sky controller should work great. You could even parallel three 100 watt panels and use it with them given the 25A spec.

I wouldn't buy Blue Sky's monitor. Others have installed the Drok battery monitor that Amazon sells for about $30. it gives instantaneous voltage and amperage and cumulative watt hours consumed or added. I am going to install one the next time we go camping and will provide feedback.

David

Is this the one you're referring to?  I'll give this a shot and if it breaks I'll have Amazon replace it.


DROK DC 0-120V 0-100A Digital Multimeter Charge-Discharge Battery Tester, Volt Meter/Ammeter/Watt Meter/Time/Capacity/Electricity Usage Monitor, LCD Color Screen with Overvoltage Protection https://www.amazon.com/dp/B01M5CWR2P/ref=cm_sw_r_cp_api_dQUszbR6F8Q8J
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on June 21, 2017, 07:22:22 PM
That is the one. I bought mine from Amazon as well and I suppose if it doesn't work I can return it. But the aggravation is more significant than the $30 ;-).

David
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: thedusty on June 21, 2017, 08:00:18 PM
Quote from: DavidM on June 21, 2017, 07:22:22 PM
That is the one. I bought mine from Amazon as well and I suppose if it doesn't work I can return it. But the aggravation is more significant than the $30 ;-).

David

Thank you. 

I now understand why you guys wanted me to get the "better" solar controllers.  But I figure since the LCD is a bonus, I'll take the risk on the cheaper stuff and see how it goes.

I ordered the 100' cable as well.

So now I have:
- Solar charge controller
- Solar panel
- Cable

I need to fill in the gaps and make sure I'm doing everything else correctly. 

This is the solar panel I already had.  I picked up a while ago while it was on a big sale.  I'm betting I'll quickly learn it's junk...so let me have it.  If it is junk, I can replace it down the line.

https://www.amazon.com/SunPower-Flexible-Connector-Charging-Compatibility/dp/B01DXYNGA0/ref=sr_1_1?ie=UTF8&qid=1498085778&sr=8-1&keywords=suaoki+flexible

In their diagram, it appears I need to add in a serious of fuses for protection.  Is this correct?  Is there a standard process for this I need to follow?

Also, my 2016 21BHS has a Zamp input on the side.  I've attached a pic.  Should I utilize this?  Or is there a better solution?

Sorry for all the newbie questions.  I'm still reading a lot online but I'm still trying to piece together the basics of how this all hooks together.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on June 21, 2017, 09:46:42 PM
Ok, this is how I would hook it all up if you have two panels:

Get a  MC4 y-adapter like this one: https://www.amazon.com/Branch-Solar-Parallel-Connector-Adapter/dp/B00V5XU74U/ref=sr_1_1?ie=UTF8&qid=1498090902&sr=8-1-spons&keywords=parallel+mc4+connector&psc=1

Plug your positive outputs of the two panels into one and the negatives into the other. Then cut off the single pos and neg branches and splice your 100' cable to it with yellow butt connectors which are suitable for 10 gauge wire.

Then on the other, RV end, buy one of these and cut it in two halves: https://www.amazon.com/dp/B0057ZQJ12/_encoding=UTF8?coliid=I3SWULPLORRIPP&colid=3RQ44LC06SQ2O

Now making sure that the male/female polarity is correct for the Zamp connector on your trailer, splice the appropriate end to the other end of your 100' cable.

Then look inside your trailer for where the Zamp connector is located. Hopefully you can find a cabinet where the back of the Zamp connector is located. Otherwise look at where the wire comes out of the back of the Zamp connector and probably drops down underneath the trailer. Then cut those wires and find a place where you can feed the Zamp end up into the bottom of a cabinet. Put your controller inside the cabinet, splice the wires to it's input then run a short length of wire to it's output and run it underneath and splice it to the wires that go to the DC controller.

The point is that you want to keep the controller dry, tucked in someplace inside in a cabinet.

I realize that the foregoing explanation might not fit your situation exactly but hopefully you can adapt and hook it up similar to my explanation.

David
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Merlin on June 22, 2017, 08:42:03 AM
That flexible solar panel is cool. Report back on how that works out.

Fuses are good. Here's a common type to splice into the + wires. One between the panel and controller and one between the controller and battery would not be a bad thing.

https://www.amazon.com/Parts-Express-Water-resistant-Fuse-Holder/dp/B0002KR88A/ref=sr_1_4?rps=1&ie=UTF8&qid=1498131290&sr=8-4&keywords=fuse+holder+10+gauge&refinements=p_85%3A2470955011
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: DavidM on June 22, 2017, 10:51:22 AM
There is no need to fuse the circuit between the panels and the controller. Solar panels are inherently self limiting in current generation and 200 watts of panels will only produce about 15 amps if the wire is completely shorted. The 10 gauge wire that you are planning to use is good for at least 40 amps continuously.

Also make sure that the wire inside the trailer from the external Zamp connector is 10 gauge. If it is smaller the solar panels won't perform well due to voltage drop in a smaller wire.

You do need a fuse to protect the wire at the battery. AFAIK there is no fuse at the battery in LL campers and this is a big safety deficiency as if the wire from the battery shorts, hundreds of amps of current can flow through it and cause a fire.

The fuse holder that Merlin referenced and a 30A fuse would provide protection at the battery. I picked 30A because that is what the battery charging wire from the TV is rated for and the 12V loads from the trailer should be much less than 30A.

So that is the only place where you need a fuse. The individual 12V circuits are fused in the converter panel as the wire used for these branches is 12 or 14 gauge.

David
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: thedusty on June 22, 2017, 11:19:07 AM
Thank you again guys. I appreciate it.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Paul on June 22, 2017, 01:30:03 PM
Quote from: Merlin on June 20, 2017, 10:16:45 AM

In fact, I just invested a couple thousand dollars in 6 volt (GC2) batteries for the solar charging station I use for my plug-in hybrid car. Great info on this site!

Your Tundra won't notice the extra 60 lbs, if you go with 2 batteries!

What kind of plug in hybrid do you have? I was looking at them a while ago and they seem really cool, I live close to work to it would work well for me. I probably won't be getting one anytime soon but in a couple of years that could be a good option for me!
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Merlin on June 22, 2017, 03:54:03 PM
Quote from: Paul on June 22, 2017, 01:30:03 PM
Quote from: Merlin on June 20, 2017, 10:16:45 AM

In fact, I just invested a couple thousand dollars in 6 volt (GC2) batteries for the solar charging station I use for my plug-in hybrid car. Great info on this site!

Your Tundra won't notice the extra 60 lbs, if you go with 2 batteries!

What kind of plug in hybrid do you have? I was looking at them a while ago and they seem really cool, I live close to work to it would work well for me. I probably won't be getting one anytime soon but in a couple of years that could be a good option for me!

We have a 2017 Ford Fusion Energi. We bought it used off a corporate lease early last spring. The dealer gave us a full tank of gas and even though we use it everyday for all our local driving, we have not purchased any gas yet; it still has 2/3s of a tank! The only time the gas engine has started was on the trip home from the dealer an hour+ away. Otherwise, it's been in all electric mode and we just charge it up each evening. It gets about 25 miles per charge in electric mode. The bonus is that it's a nice car too!
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: thedusty on June 22, 2017, 04:19:24 PM
Quote from: Merlin on June 22, 2017, 03:54:03 PM
Quote from: Paul on June 22, 2017, 01:30:03 PM
Quote from: Merlin on June 20, 2017, 10:16:45 AM

In fact, I just invested a couple thousand dollars in 6 volt (GC2) batteries for the solar charging station I use for my plug-in hybrid car. Great info on this site!

Your Tundra won't notice the extra 60 lbs, if you go with 2 batteries!

What kind of plug in hybrid do you have? I was looking at them a while ago and they seem really cool, I live close to work to it would work well for me. I probably won't be getting one anytime soon but in a couple of years that could be a good option for me!

We have a 2017 Ford Fusion Energi. We bought it used off a corporate lease early last spring. The dealer gave us a full tank of gas and even though we use it everyday for all our local driving, we have not purchased any gas yet; it still has 2/3s of a tank! The only time the gas engine has started was on the trip home from the dealer an hour+ away. Otherwise, it's been in all electric mode and we just charge it up each evening. It gets about 25 miles per charge in electric mode. The bonus is that it's a nice car too!

At some point in the next year I want to add a used Nissan Leaf as a third car. You can get them used for about $7k if you hunt. They are all electric and can do about 70-80 miles...which more than covers the vast majority of our daily local driving. We will keep the Tundra for trips and towing. Beyond new wiper blades they don't require much maintenance. The brakes apparently even last forever since it's mostly doing regenerative breaking.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Merlin on June 22, 2017, 10:03:46 PM
If only we knew someone who could talk Amazon into selling electric cars............. :o
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: thedusty on June 22, 2017, 10:37:57 PM
Quote from: Merlin on June 22, 2017, 10:03:46 PM
If only we knew someone who could talk Amazon into selling electric cars............. :o

I'll let you know what Bezos says.

They do have some rockets you can rent at Blue Origin right now though...
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: GoElectric on June 23, 2017, 04:47:54 PM
Definitely give a new or used Chevy Volt a try for those interested in electric cars. We have had ours coming up on 6 years with over 100,00 trouble free miles with no degradation of the batteries with the proactive battery management system and they drive great.
Title: Re: 2 -(6v) batteries vs 2 (12v) batteries
Post by: Powder Hounds on March 26, 2019, 04:16:32 PM
Perfect thread!

I finally got around to make this adjustment, cleaned the fridge compartment up as well. Tree needles and lots of dust and dirt.

Thank you all!

PS We installed a master kill switch for our stereo last year, now with the frame heater eliminated we have no unnecessary power draws.