50w Just for charging

[tjwoods1]

I am considering a solar panel setup only to keep my batteries charged when I not using the Airstream (I have two 12v hooked in parallel). It would not be a permanent mounting. Would a 50 w panel be enough to do the job?

[AWCHIEF]

50 watt panel with perfect all day angle to the sun should give you 4.2 amps. That is in a perfect world, real world will be less than 3 amps average. That might be enough to cover parasite draws but not much else.

[Al and Missy]

... depending on the condition of the batteries and shadowing of the panels. If everything in the trailer is turned off ( you may have to make wiring mods to turn off the propane detector if you have one), self discharge would only be a few hundred milliamps per battery. Good batteries would probably be around 100. So 200 mA times 12 volts is only 2.4 watts, or about 58 watt-hours per day. You'll get around 4 hours of effective charging per day best case, so a 50 watt panel could deliver as much as 200 watt-hours per day.

You'll want to be sure your charge controller won't overcharge the batteries. You can't just hook a panel up to the batteries without risking overcharging them when you have good sunlight.

Just my opinion, your mileage may vary.....

Al

[dznf0g]

I have a 15w storage panel that works just fine with disconnect switch off. With parasitic draw of about 150mA, I get 750mA of charge power. It keeps my 2 group 29 LA batteries charged up just fine per the Trimetric monitor.

[Wayne Clamp]

seeks what size solar charger is needed to maintain 2 twelve volt batteries in series, has generator thus only want to maintain batteries when stored.

[Wayne Clamp]

I am trying to determine what size solar generator is needed to maintain 2-12 volt batteries in series. Not trying to use for anything other than storage maintenance. Have generator for the other part, roughing it does include air conditioning, wife say

[Inland RV Center, In]

Originally Posted by Wayne Clamp

I am trying to determine what size solar generator is needed to maintain 2-12 volt batteries in series. Not trying to use for anything other than storage maintenance. Have generator for the other part, roughing it does include air conditioning, wife say

Are you sure you have the 12 volt batteries in series?

If so, you need a 24 volt solar charger, which basically is not around.

Put the batteries in parallel, and then get a 25 to 30 watt solar 12 volt charger.

That is more than enough to keep your 2 batteries "topped off".

Andy

[Wayne Clamp]

Thanks Andy, I got my series and parallel ass backwards

[Wayne Clamp]

Thanks again Andy, I settled on a 50 watt Renogy