new AGM

[jaramanpotter]

I am putting in new AGM batteries replacing Wet cells. I can fit 2 x 160 AH and 2 x 225 AH in parallel. The supplier says I cant mix different AH rated batteries?I had these batteries in a previous boat, mixing AH ratings with no apparent issues. I want to keep it simple but maximise the AH. What does some one clever think?

[skipmac]

Yes you can mix batteries of different amp hour rating, as long as they are the same chemistry. Also preferable (but not essential) to be the same brand as some manufacturers specify slightly different charging regimens for the same type battery.

[jaramanpotter]

Thanks Skipmac.....just what I thought

[hellosailor]

You can mix them, but since they are different capacities they will charge and discharge differently, cycling to different depth of discharge, so placing more of a load on the smaller batteries and probably shortening their lives.

Yes it will work, and you'll probably never notice. Except you'll be getting less overall life and capacity and probably replacing the smaller ones sooner. If you figure four years is normal, you might never notice that you could have gotten six with a fully matched set.

If the unmatched set is all you can do, that's what you do.

[john61ct]

If it is an expensive large bank and you care about maximizing longevity, don't, all should match, even mfg date.

Otherwise don't worry be happy, maybe get them all in sync next time

[skipmac]

If I may ask, why are you going with AGM instead of FLA?