So, I managed to get nine free batteries from my homeowners association for free! They were going to get rid of them and mentioned that most of the batteries still had at least a year of life left. Six of them are US2200 and the other three are Trojan 105, all are 6 volt batteries.
I tested the trojan's and I think they are probably completly dead. Open volt test showed 5 volts. I think they sat around for over a year. The other 6 US2200's seem like they're still good. Open volt test produced over 6 volts for each.
I might try doing a gravity test on them later, just need to buy the tool and learn how to use it.
Soo, here's how I thought about wiring the batteries together (using 6 gauge battery cable's):
I also have an existing 12v marine deepcycle battery that I thought about wiring into this battery array. Here's how I thought about wiring it in:
Is this a bad idea? I've heard mixing batteries is usually a bad idea, but I think that only applies to batteries that are placed in series?? I might be wrong. Also, the six US2200's might be in different condition... could that have a bad overall effect?? I'm thinking that even though I'm mixing batteries, it's still a huge improvement from my single 12v 75amp hr battery.
This battery array would be charged using 93watts of panels (two 45 watt HF panels and a small 3 watt panel).
... thoughts?