mixing sla batteries with different ah

[DanSFIV]

Hi,

I have 4x12v18ah and 2x12v20ah sla lead acid batteries. Is it possible to mix them together to use on my 72v controller?

thx

 

[ZOMGVTEK]

Yep.

In series, you will only get as much capacity as the weakest cell can deliver. So, your total pack will be more like a 72V 18AH one, the 20AH batteries will just have a bit more juice left you can't use. 18 and 20AH is close enough that you will probably barely even notice, especially with lead.

1.3kWh of lead sounds very heavy. Is this going on a bike? Also, don't expect to get anywhere near 18AH out of an 18AH SLA.

 

[amberwolf]

I've used 17, 18 and 20Ah all mixed in series on CrazyBike2's old powerchair motor drivetrain, and they worked fine together. But at best I probably got half the Ah of the lowest-capacity unit in the stack. It's just the nature of SLA. Actual usage/capacity numbers on this are in various posts on my http://electricle.blogspot.com , if you need them.

Also, those batteries tend to weigh around 15lbs each...so six of them is 90lbs or so.

 

[DanSFIV]

ok thx guys, ill trying it again when another warm day comes

 

[DanSFIV]

i have 8x12v20ah and 4x12v18ah ---> 2 x escooters


right now i have it as 1 pack as 4x12v20ah+2x12v20ah and my 2nd pack 4x12v18ah+2x12v20ah


would it be better to split the 12v18ah batteries as 2x instead of a 4x pack?

so it would be

2nd way

1 pack 4x12v20ah+2x12v18ah
2 pack 4x12v20ah+2x12v18ah

i had my bike setup the first way

thx