Mixing 'types' of AGM batts??

[John Drake]

Hello everyone

I have what is most likely a dumb question, please forgive it in advance.

I have two group 31 AGM deep cycle batts in my house bank. My energy budget is low and they have worked well for the past couple years I have had them and this year of cruising and living aboard full time. One thing though...I have noticed that when I apply a high draw item like my computer or talking on the SSB...the voltage can drop significantly, very quickly. I am given to think this is due to their slower rate of electro-chemistry. No problem with capacity, after the draw is taken off, they equilibrate pretty quickly and the voltage comes back up.

I want to add more capacity to my house bank.

SO....I wonder...aren't there "dual purpose" AGM batts??? Batts that have thinner plates and can deliver charge more quickly?? They cannot deep cycle as many times as the 'deep cycle' ones...but that is not really an issue for me. SO...could I mix these two in order to maintain voltage?????

If I mix the two would the drain then come preferentially from the dual purpose batts, draining them faster and thus ruining them? Then when they are ruined, will they in turn ruin the deep cycle AGMs??

Hopeful for any advice. I know I could simply add more deep cycle batts to the house...but they are the most expensive and I wonder if voltage drop will still be an issue.

Thanks

Best

John
s/v Invictus
FL Keys