Mixing Battery Amp Hour types

[dunworkin]

Hi All..and thank you for my newbie questions concerning Solar systems.

I presently have (1) 100w 20vdc panel charging a bank of (6) 6v GC-2 flooded batteries configured for 12v. The batteries are Golf Cart Stowaway 6V, 110mins@75 amp units. I believe to be about 200amp/hour units, giving my Bank 600AMP Hours at 12 volts the way configured (I Think this is correct). I know my panel is too little here in Maine, and do intend to add two more panels for 200w more chrging. Can I add two large 385 AMP HOUR 6V Trojan cells to my present bank to increase my storage to close to 1000AH? THe battery size and  AH is differnet , but they are all 6 volt wet cells. My Prostar controller takes care the the configuation. Can I mix sizes like this.

THanks for the help.

[wpowokal]

I do, but the purists will say no!

allan down under

[Sparky01]

Battery age and capacity is something to try to stay away from. It is often hard enough to keep all the cells equal. It really depends on what you are doing with your system and the amount of money you have in it. Where are you in Maine? I live in Unity. BTW I think it would be great if this site had a way for people in the same area to be able to meet.

[Seaspray0]

If you hook batteries in series to create a bank, they must be of the same type and rating (preferably the same age as well).  A bank of batteries can be placed in parallel with another bank of different amperage ratings (refer to the first sentence reguarding building a bank).

Reason, all the batteries in a bank (series) must be the same or their voltages will not maintain equally as they charge/discharge.  All banks in parallel will have the same total voltage but supply different amounts of current when charging/discharging.