Anyone know anything about Wiring solar panels...

[toyotapriusguy]

into a bank of deep cycle batteries? We use panels at home and they're wired into the grid, which was done by a real electrician. However, with the recent hunt for an RV and a desire to keep it as green as possible while burning fuel at an alarming rate, we'd like to put a bank of 4 to 6 deep cycle batteries and a panel or 2 to charge them during the day so that we could avoid using a generator as much as possible.

So a long post shortened, how do I decide how many amps watts and volts from a solar panel do I need to charge say 4 deep cycle 12 volt 1000 CA batteries?

Thanks in advance ladies and gentlemen

 

[wrcsixeight]

Well, first off, most true deep cycle batteries will not list Cold Cranking Amps. If they do, it is likely a sign that they are probably dual purpose batteries, and not a true deep cycle battery, like a 6 volt golf cart battery is.

Cold cranking amps are listed to determine how quickly the battery can release it's stored energy, to crank a starter motor. Generally bigger batteries have more CCA, and starting batteries will have more than deep cycle batteries, but starting batteries cannot handle many deep cycles before dying.

True 12 volt deep cycle batteries do exist, but they are difficult to find compared to the Marine/RV/Trolling/"deep cycle" batteries easily available.

Battery capacity is generally measured in amp hours(the 20 hr rate), and most larger batteries, (group27) are 100 to 115 A/h each.

It is said that batteries are happiest when the can be recharged at 5 to 13% of their a/h capacity, so a 100 a/h battery should get at least 5 amps, which is about what a 100 watt panel will likely output midday in the summer.

I have 130 watt panel and I will see about 7.4 amps from it.

Sites like rv.net and Northern Arizona wind and sun forums have lots and lots of info about setting up a system for an RV.

 

[Shannow]

No biggie at 12 volts, but remember that solar panels are "live" all the time.

 

[eljefino]

If they're permanently mounted outside the RV, make sure their wind resistance while travelling doesn't undo what good they do.

 

[toyotapriusguy]

I'd like to mount them in a way to minimize wind resistance and even make it easily removable in case we do take a longer trip and even the minimum resistance would have an effect. Usually travel with the electric scooters and bikes so the RV really just serves as a transport and hotel room to where we are going and not really something to tool around where ever we might be visiting.

 

[morris]

a friend of mine runs his whole house on solar panels. and a large bank of 12v and 6v batterys. all i know is that you need a lot of 10amp diodes. but i dont know how to hook them up.
west florida components
T10A60L 10A 10 AMP 600V Diode Axial

its hard to find diodes of that size. ill get more info and post that