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

It will help but a residential frig uses a lot of energy. If I was mounting a panel I would buy 160 watts or so. It takes the same number of holes in the roof as a 100 w. You wire the panel to the controller and the controller to the batteries. Fuse or use re settable breakers so you can disconnect the panel before disconnecting the battery cables. Some controllers dont want solar power coming in while the battery is disconnected.If you were sizing the solar bank to the battery you would want about 100 to 150 watts to each 100 ah of battery capacity. You have about 400 amp hours of battery. I started out with four 6 volts and 520 watts of panel. It worked well and we use a lot of power for furnace, led television etc. When I installed our residential frig I added 2 more batteries and 480 watts. So about 600 AH of battery and 1000 watts of solar. If you want to add more panels later you may want to consider that now. It is very common to add more.

Thanks. So which battery terminal would I hook up the alligator clips? I think I'm going to go with 200 watts solar and a 30a controller. it says it can handle up to 400 if we need more power. In the long run if I do a nice system like yours (1000W solar) all i would have to replace is the controller and buy more panels correct?

Magnusson, seems to me you are disregarding rjxj's sound advice...100 to 150 solar watts per 100 amps of battery. Why? "In the long run if I do a nice system like yours (1000W solar) all i would have to replace is the controller and buy more panels correct?" And the alligator clips! Do a 400 watt solar system and do it right...including no alligator clips.

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. I'm not going to mount on the roof yet, just place on top upon arrival. The renogy solar kits look to come with alligator clips or O rings to attach to battery terminals. Just wondering which terminals of the 4 batteries that I would attach too and if its ok.

The controller will have a positive and a negative from the panel and a positive and a negative to the battery. Keep the controller near the batteries but not right by them where it may be damaged. I wouldn't necessarily use alligator clips. A rubber covered connector whole be better. It would use ring terminals on the battery studs.

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

Njmurvin
Explorer
May 26, 2017
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
Nomad
May 25, 2017
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
Explorer II
May 24, 2017
"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
Explorer II
May 24, 2017
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
Nomad
May 24, 2017
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
Explorer
May 24, 2017
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
Nomad III
May 24, 2017
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
Explorer
May 24, 2017
http://roadslesstraveled.us/rv-solar-power-tutorial-small-upgradeable-solar-system-for-summer-weekends-vacations/
azrving
Explorer
May 24, 2017
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
Explorer
May 24, 2017
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.