Battery Bank

My dad and J have been working together to get the solar system and battery bank up and running.  It has meant a lot of long nights for J and a lot of phone conversations with Dad.  I would like to include more detailed information about what they have done, just for those people who might be using this blog to figure out some of their own solar systems, but for the moment I'm going to write it how I understand it.  Always feel free to contact me if you want all of the excel spreadsheets, scientific graphs, and research articles (thanks Dad!).

So, when we bought the house, the sellers added eight new deep cycle batteries to the battery bank.  That's almost $1000 in batteries.  We thought it was great that they were willing to do that.  The thing is, they chained them into the system without removing the old batteries.  Not so great.

The problem is that when you put old, tired batteries together with new batteries, the old batteries slowly kill the new ones.  I'm sure that it isn't premeditated, but the old batteries can't help themselves.  So when we would start up the generator (or when the solar panels were charging up the system), the old batteries would take all that they could handle and then they would say STOP.  Well, the new batteries weren't getting what they needed to keep a good charge and were slowly getting weaker and weaker.  Batteries don't like to sit without a charge...so the longer that the new batteries sat without a good charge, the worse they got.

The solution?  Remove all of the old batteries and try to revive the new ones.  It seems a little counterintuitive to remove half of your battery bank.  But under these circumstances, the old batteries were holding something like a 60% charge and the new ones were doing very little, if anything.  Now that we have removed the old batteries, the new ones can give us a lot more than 60%...thus, we are actually better off with half the number of batteries in the battery bank (under these circumstances).  We will find other uses for the old batteries.  They will work fine for the fence charger or other small projects around the property.