Charging several batteries together

Brian Liddell

Just Joined
Mar 29, 2019
4
0
My Moulton TSR bike uses Oregon 36v 6Ah garden tool batteries and chargers:


I connect one battery at a time to the controller, using a DIY lead with copper contacts that go into the battery at one end, and an Anderson Powerpole connector at the other.

I'm about to convert my wife's Brompton to electric too, and I'd like to use more of the same batteries.

But, I don't want to have to charge four batteries one at a time, so would it be OK to connect all four batteries together and charge them all at once?

How should they be connected?

I'd be quite happy to get a new charger, as the Oregon charger is very bulky to take away from base.

Thanks in advance for any advice!

Brian Liddell
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,985
Basildon
No, that's not advisable. effectively, you'll be charging three of them through the discharge terminals, which bi-passes the charge safety controls.

You need multiple chargers like this:
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
19,990
8,172
60
West Sx RH
Each battery has it's own BMS inside so you can't reliably charge all at once.
RC users and I as have with lipo blocks charged several in parallel but without BMS.