pv/solar power bbu

[ILCML]

I need to come up with a battery backup charging system using a solar panel. The batteries will be running a 1.3HP DC motor with an FLA of about 60 amps. The battery will be a couple of car batteries in series.
Using the 20% ROT, I figure I need around a 300W charger. However, most solar panel sites I'm seeing don't offer anything that big....should I just use a much smaller one and deal with the long charge time, or do I just need to get a few 100W panels? Naturally I would like it to be as affordable as possible....Any input appreciated.....

 

[itsmoked]

Hello.

I just went thru this whole subject in detail - a complete waste of time as the OP divulged a really stupid application - but the information is spot on.

Read this thread and follow up with any questions in this thread.
thread956-188937

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[ILCML]

I hope I understood your request correctly (to reply in THIS thread )
Ok, so this guy wanted a cordless lcd picture frame? Ok...

After some looking around, I've learned that the car battery is a pretty solid dude. Lets see if I have this right:
A 225 reserve capacity provides 25A for 225 minutes, or around 3-1/2 hours, effectively giving it a AH rating of 94?

If that's the case, I can get my ~32A for 3 hours out of a pair of car batteries....at your 60% efficiency determination, we'll say a little over 2 hours. At a 10 second motor cycle, I should easily get 200 cycles without draining the battery beyond the scary level....Am I off here?
Then If I have a wimpy (not a 300W $10,000, maybe a 25W or so) smart PV charger connected, the system should work ok....

 

[itsmoked]

Yes, in here is what I meant.

Couple of points. You should not be using car batteries. They are about the worst thing you could use for this type application. Use a deep cycle battery, NOT a starting battery. The one I mentioned in that other tread is an excellent battery for not much money.

There are a lot of subtleties to doing a solar system that can result in its being effective and pain free or a cantankerous pain in the butt that eats batteries like candy.

Can you describe your system to us in far more detail, like the frequency of operation the location etc., as then we can give better advice.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com