Battery bank upgrade

Rhylsailer99

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Last year I upgraded to a 130ah agm expedition plus and kept one of my 130ah lead acid batteries. Each battery was on a seperate circuit ie 1 or 2 . I have since got a dedicated starter battery 75ah and kept the one 130ah agm with the intent to buy an identical one and bank them together. I can no longer buy the equivalent battery and after doing some research realise it's maybe not a good idea with the battery already 12 months old.

The question is, are agm batteries worth the extra cash?
I was thinking 2x115ah agm
Pardon our interruption...
or would it be wiser to get 1 lithium and a dc to dc?
Or the cheaper option just 2 x lead acid leisure batteries.
I never really rated the agm battery as it seemed to loose volts fast during use, maybe it was a dud.

I also have 140w of solar to keep topped up.
 
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What sort of usage do you have? In some cased LFP would be better, in others SLA will do just as well .. how do you use the boat and the power?
Fridge, laptop charge and mobile phones charging. I think I will just get lead batteries. Messing about with dc to dc seems like more drama. I have had enough of drama after doing my engine mounts, on my own whilst swinging on the mooring.
 
My experience of adding a new LA battery to one a few years old was perfectly OK. I think I got a few years out of the bank after the merger. I don't expect more than about three years on a six-month liveaboard boat.

As Vyv ... if the old on-baord battery is still able to do its job .. adding a new battery to it as parallel is fine ...

When I replace batts on my boats - I do singly ... no point wasting the remaining years of the other !! Some say that a new battery will then be 'carrying' the old and working harder ... but that's only case when old battery is barely able to do its job .. then yes - both out.
 
As Vyv ... if the old on-baord battery is still able to do its job .. adding a new battery to it as parallel is fine ...

When I replace batts on my boats - I do singly ... no point wasting the remaining years of the other !! Some say that a new battery will then be 'carrying' the old and working harder ... but that's only case when old battery is barely able to do its job .. then yes - both out.
The same battery just came into stock today so I bought one. I will take a chance as the 12 month old one has only had light use and been kept topped up by solar.
 
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