Multiple Batteries in Parallel
I have several regular 12v batteries that are different sizes. Can I safely hook them up in parallel without damaging any of them?
Forum Discussion
dons2346 wrote:
Your battery pack will be as good as your smallest battery
FALSE
FactL the batteries will work it out in a perfect commune. each according to its ability (Whebn delivering power) each according to it's need.
I will use a 2 battery system as an example a 130 amp hour Group 31 with a 70 amp hour Group 24 in parallel
IF you are drawing say 10 amps. the smaller battery will be putting out 3.5 amps and the larger one 6.5 (Total 10)
If you are charging at 10 amps.. The smaller one gets 3.5 and the larger one 6.5)
No matter the courrent that 35/65 ratio will apply
Once they have cycled ONE TIME they will be in perfect lock step state of charge wise. The instant one is "FUll up" so is the other.
NOW. THe danger....
With batteries in SERIES (Does not apply here) a shorted cell in one can damage the other (over charge)
With batteries in PARALLEL and for this it matters not if they are the same size or different sizes with one minor exeception. A battery with a shorted cell may "Explode" (not that big a deal more of a pop than a boom)
The danger is greatest if the smallest battery has the shorted cell.
But it is there even if the batteries are twins.
