2 -(6v) batteries vs 2 (12v) batteries

[DavidM]

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

[Chappy133]

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.

[DavidM]

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

[Chappy133]

 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.

[tbrady]

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??

[DavidM]

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

[tbrady]

Doh!  Thanks for the correction David.  I knew that sounded too good to be true!

[thedusty]

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.

[gbpack]

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.

[DavidM]

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

[thedusty]

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?

[gbpack]

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.

[thedusty]

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.

[Merlin]

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!

[thedusty]

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