Charge two 14s 18650 packs together?

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DiggsUt

Member
Joined
Oct 30, 2019
Messages
65
I've been asking around the ebike forums but seem to get no answers so I thought I would mention it here -

I have a BBHSD mid-drive ebike with a Wolf v2 (14s4p 4-port=2 ports with XT60 connector for charging and 2 ports XT90 for power) pack. I'd like to increase my range and will plug a second pack into the second XT90 connector (first XT90 goes to the controller) of the Wolf and slave a 14s5p pack to it that I built (with BMS from 2900 mah cells that can charge through its power port). I've received one recommendation to charge them separately but I'm not sure what that is based on. Capacities are almost the same so I can't see an issue with leaving it connected to the Wolf pack and charging the Wolf pack through it's charge port thus charging both packs at the same time. I'm wondering if I'm missing something here and if there might be a problem I don't recognize? Anyone have advanced knowledge in this area? The biggest problem charging separately is partial charges and getting them both to the same state of charge before reconnecting. No problem if 80, 90 or 100% charge on a Luna variable charger but that's not always possible. I could also use a Y-cord for charging but why bother if I can just leave the aux pack connected to the Wolf and charge the Wolf ending up with both charged. No response from Luna that makes the Wolf pack. Anyone been here before? Any thoughts?
 

daromer

Moderator
Joined
Oct 8, 2016
Messages
5,659
IF both have its own bms its fine.
 

jdeadman

Member
Joined
Mar 28, 2017
Messages
939
Just when connecting the 2 packs together check and verify they are at the same potential. I use a 1W 10 Ohm resistor to slow the current for any batteries that are not the same just to eliminate the big Amp draw and Spark associated, But i have not had problems doing this. I do connect my portable Power station to my home power wall to increase my capacity when the mobile one is not in use
 
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