Batteries with different Ah ratings

[Copious]

Hello All,

I have two battery banks: The first 1 x 62Ah for engine start and the other 3 x 62 Ah for the domestic supply. If I add another battery to the domestic bank, does it also need to be 62Ah? Is there any imbalance in charging if the new one is larger?

For info the alternator/generator is 60A and the whole system is 12v.

Thank you in anticipation,

Copious

 

[mandlmaunder]

Depends now how serious you are in battery tech and 12v gobbledegook . many long term cruisers add battery's as and when they can afford them and seem to have no major inbalance prolems, others will have a fit if 1 battery lead is 2 inches longer than the others as this is known to throw an inbalance that could course the entire world to wobble and the end of civilization as we know it.
If you are comfortable with mixing different amps And ages of batterys then go and have a good time with your higher and more bependable battery banks .
Just be aware that the maintenance your regime will be higher as different batterys charge and hold better than others ,there by coursing different amounts evaperation in each battery.
Have you confirmed that more battry is the way forward rather than a more efficient charging system fitted to you alternator and or solar panels.

PS SHWMBO has put new aviter up ,we really do look like that,
cruising still agrees with us

 

[William_H]

There is probably more concern about old batteries with new batteries rather than different sized batteries. But the short answer is no problem.
I would suggest however that you either fit or occasionally treat the house batteries individually so you can determine their actual performance. By this I mean make sure the batteries are reasonably well charged. Then disconnect the others so that only one battery is used for the domestic load and note how well it performs. You should be able to get 50% of rated AH out if it is good. Then proceed to check the other batteries in a similar manner. ( A bad battery will drop dead PDQ.)

Another battery in paralel will improve your overall capacity and also will increase the charge rate when recharging. good luck olewill