Technical battery question

[Stuart Adair]

Hi,

I've got 4 leisure batteries and a starter batteries on my boat. Three of the leisure batteries were bought together and are 130AH with 100% SOH. The fourth battery is 110AH showing 83% SOH. Which option will give me the best overall performance from my battery bank ? Run with three matches 130AH 100% SOH batteries, or run with all leisure batteries, including he 110AH 83 SOH one ?

Many thanks

Stu

 

[Sticky Fingers]

I’d not mix them in one bank. Assume this is a 12V boat not 24V?

 

[rafiki_]

Yep, SF is right. All 4 batteries in the same bank should be the same spec, and preferably installed at the same time. The one poorly battery will drag the others down.

 

[Skipper Felice]

As I had to study many battery issues last summer and replaced some of my battery / electrical system I would recomend that you keep the 3 good batteries in one bank - they should last for some time and you should have a good monitoring / charger system. The other (perhaps bad / dead) battery shoul be replaced - no big deal - and as the (starter) battery separted from the service battery bank.

 

[Refueler]

In fact you do not have to have same capacity batterys together - as long as they are same voltage and dicsharge capability ... the capacity is not a problem.

Obviously age and chargeability is and its always best to renew batts in batches and not singly .. even though many people do.

To OP ... the 4th battery will likely degrade faster and eventually drag the other three down as it does ... I would be inclined IF you are confident of the three - to replace the 4th ... getting the bank up to full capability.

I assume that you have 4 domestic batts and one separate starter battery ? Your posts wording is a bit unclear ..