new batteries in old bank

palausystem

I read that you shouldn't do it, but - One cell with consistently low SG, one battery leaking electolyte at the top-to-side joint, received two free replacements under warranty in 7 year old 16 Surrette S-530's. Question: will installing the 2 new batteries help the old bank last longer, or just cause more problems?

Blackcherry04

Re: new batteries in old bank

It's always comes down to economics. The new batteries will be pulled down to the level of the old ones in short order. You have say $800 in 2 new ones that were paid for by them, on the other hand you have $5,600 in 14 old batteries. If you find they still have the required capacity to get you by, I'd put them in and roll the dice. If your capacity is shaky then you need to think it over. Two extra batteries just become a pain.

palausystem

Re: new batteries in old bank

It sounds like you're saying that installing the new batteries wouldn't cause problems, that they would simply end up prematurely "aged".
The scenario I'm dealing with is that our capacity has been OK, I'd like to get a few more years out of the bank and was concerned that the low sg cell would drag the rest of the bank down way before its time. And since I think our next set of batteries will not be Surrettes due to cost, well, there you go. I suppose I could try to "hammer" the low cell with some hostile charging to see if it comes back, caulk the leaky battery at the seam (?) leave those in and use the juicy new surrettes in the shanty in the woods.

One other question: Will a "smart" charger get confused by the slightly higher voltage in the string where the two new batteries are, while the other string is all old batteries?

Blackcherry04

Re: new batteries in old bank

It's always a tough call, All the battery bank I deal with are GC-2's, 8 - 10 batteries and they are one and done on the warranty. If the are under 4 years old, I'll replace one, over that I recommend to dump them, but they all charged with gas generators at $8- $10 a hour for fuel and that factors in.

Yep, if you have another use for them, do it and work on the others. Put the leaky one in a plastic battery box and see what you can do with the other.