12 Volt Solar panel for 4 6v batteries in series parallel

[magnusson]

I decided to go with 4 6v gold cart batteries wired in series parallel to increase my amp hours to run a residential fridge. Can I use a 100 watt 12v portable solar panel to help charge the battery? If so how would I wire it? Thanks

[Njmurvin]

theoldwizard1 wrote:

magnusson wrote:
Can I use a 100 watt 12v portable solar panel to help charge the battery? If so how would I wire it? Thanks

100 watts is better than nothing. Just connect the output of the solar charge controller to the output of the battery bank,

It's barely better than nothing. OP has described 400ah of battery bank. He can safely discharge about 50% or 200ah. Depending on sun, angle, wiring used, etc. he will be lucky to get 6-7 usable amps at the controller in maximum daylight with a 100 watt panel. At that rate it would take about 30 hours of maximum sun to recharge 200ah.

Just basic parasitic loads (smoke alarm, propane detector, etc.) will use about an amp. Add some (very few if not LED) lights, water pump and other necessities, it doesn't take much to rack up 20-30ah overnight when the sun's not helping. This alone would be recoverable with a 100 watt panel. Add more loads than this (residential fridge, TV, DVD player, furnace,etc.) and you better bring a generator along.

[laknox]

Lwiddis wrote:
"being charged with 8 435w commercial grade solar panels. Whole coach will be electric, except for the water heater."

That is a serious solar system!

Ya think?! :B Induction stove, residential fridge, 1, maybe 2, heat pumps OFF THE BATTERY. Cool setup and I can hardly wait to see it.

Lyle

[Lwiddis]

"being charged with 8 435w commercial grade solar panels. Whole coach will be electric, except for the water heater."

That is a serious solar system!

[theoldwizard1]

magnusson wrote:
Can I use a 100 watt 12v portable solar panel to help charge the battery? If so how would I wire it? Thanks

100 watts is better than nothing. Just connect the output of the solar charge controller to the output of the battery bank,

[laknox]

magnusson wrote:
I decided to go with 4 6v gold cart batteries wired in series parallel to increase my amp hours to run a residential fridge. Can I use a 100 watt 12v portable solar panel to help charge the battery? If so how would I wire it? Thanks

Check out my cousins' blog, www.beginningfromthismorning.com (they're on Facebook, too). They are rehabbing an old bus for a full-time RV. Juan has decided to use the battery pack from a Nissan Leaf, being charged with 8 435w commercial grade solar panels. Whole coach will be electric, except for the water heater. 🙂

Lyle

[dave17352]

Magnussan I think I bought the same kit as you. It works great. If you want us it as a portable that should be no problem. What you need to understand is wiring the controller in is nothing more than sticking the wires from the solar panels into the controller and running two more out to your batteries. It doesn't have to be set up permanently to do this. The controller will give your batteries the proper voltage from the solar panels.

[pianotuna]

Magnusson This is what is balanced and best for twin twelve volt batteries.



As it often doesn't cost a dime more to do this, I think it is worth the trouble.

If you wish to understand the "why" surf here:

correctly interconnecting multiple twelve volt batteries

Others may say it doesn't matter--but unless there is a compelling reason to not optimize charging and discharging why not do it the best possible way?

[goducks10]

http://roadslesstraveled.us/rv-solar-power-tutorial-small-upgradeable-solar-system-for-summer-weeken...

[azrving]

magnusson wrote:
Ok copy. So if I put the positive from the solar panel to the positive on one battery and the negative from the solar panel to the negative on the same battery it will charge all 4 batteries. Thanks

Being new to this stuff you may have missed the word CONTROLLER? You need a solar controller. We are trying to help you but you may be better off if you have someone do this for you so you so that it is safe. Even making connections at the batteries has it's risk of explosion if done wrong. Get someone that knows what they are doing and perhaps they can explain it as they work on it.

[sch911]

magnusson wrote:
Ok copy. So if I put the positive from the solar panel to the positive on one battery and the negative from the solar panel to the negative on the same battery it will charge all 4 batteries. Thanks

No...

The leads should be connected to the 12v series parallel posts that the TT uses. This will be the positive post on one battery and the negative post on another battery.

[Sam_Spade]

magnusson wrote:
No not disregarding at all. Just have a 3 day boondock coming up soon and don't have big cash to spend on a nice solar system yet.

So.....you are going to waste cash now because you can't afford to do it right ??

To upgrade later, you will pretty much have to replace the whole system. When you replace the panels and controller, the only thing left is a few wires.

It sounds to me like you are in over your head, budget wise and maybe you can't afford to run your fridge on a trip like that right now.
It is possible to camp for 3 days without a fridge.

But......if you insist on doing it anyway, for making the connection at the battery you find the cables LEAVING the battery bank and connect there. Under no circumstances, with 4-6 volt batteries, would you connect both charging leads to the same battery.

I don't understand why people ask for advice and then ignore what comes back. Why bother ??

P.S. Can someone provide a link to the 12 V tutorial ? I didn't save it. You NEED TO READ THAT. And get an inexpensive multi-meter.
Just because you know little to nothing about batteries now doesn't mean that it needs to stay that way.

Remaining ignorant can be disastrous.

[pianotuna]

Not using a controller may be penny wise and pound foolish.

The Grape 40 amp controller is quite inexpensive and extremely flexible for use.

For my detailed thoughts on solar, surf here: lhttps://freecampsites.net/adding-solar/

[time2roll]

Connect at 12v potential same as the RV main connection.
Disconnect at night if no controller.

[magnusson]

Ok copy. So if I put the positive from the solar panel to the positive on one battery and the negative from the solar panel to the negative on the same battery it will charge all 4 batteries. Thanks