Wiring a dual voltage battery pack

Thread Starter

reuben.hegerty

Joined Aug 2, 2022
1
Is it possible to wire two small 12v batteries with a DPDT switch to achieve both a 12 and 24v output but in the 12v mode have both batteries in parallel? I just need a yes or no but some info on this would be good aswell. I'm only 16 so keep the answers fairly simple.

Cheers.
 

Irving

Joined Jan 30, 2016
2,979
Its perfectly possible as long as these are rechargeable batteries; don't do this with non-rechargeable. I do this with my wheelchair's 24v lithium pack for outputting 12v to jump-start the car, or charge them from the car. Given the currents involved (50A or more) I don't use switches but a pair of Anderson connectors with different wiring. The important thing is to make sure the batteries are balanced when charging; ideally charge them at 12v in parallel so they are similar voltages.

The worst thing you can do is use one battery for 12v and both for 24v. If you do this the one used for 12v could get over-discharged or the other could become over-charged if you use or charge both in series for 24v.
 

MisterBill2

Joined Jan 23, 2018
12,690
Shot answer is YES. But certainly the cautions mentioed apply. Also, it can be arranged to have the two batteries either in series or in parallel, which may be an advantage in some cases.
 
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