Brammo Owners Forum
Brammo Enertia Discussion => Brammo Enertia Mods => Topic started by: biohazard on December 21, 2020, 12:28:05 AM
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I've noticed that the charger for these bikes is only rated for 750w.
That's about 9.7A at the batteries' 76.8v nominal voltage.
That is only .25c charge rate for the valence batteries since they are 40AH.
Has anyone tried charging with a different charger that puts out more power?
The datasheet for the valence battery packs suggests that a 20a(.5c) charging rate is standard, and that the maximum charge rate allowable (think dc quick charge on a car) is 40a(1c).
I'm going to leave it as it is for now since I just got my bike, but I will probably get a generic smart charger rated for lithium iron phosphate to charge at 25A in the future. Maybe I'll rig it up with a j1772 adapter and keep it external and just install a plug to directly connect to the batteries for when I want to charge that way, like if I wanted to go on a trip.
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I think the performance of the on-board charger is lower because Valence batteries do not have active temperature control. Therefore, their service life when charging at extreme temperatures could be significantly reduced.
I recommend not to increase the charging power. The new Valence batteries are expensive and difficult to obtain. In addition, they need to be programmed for use in Brammo Enertia. If you do not have Brammo diagnostic software and hardware for Valence batteries, no one else will be able to help you.
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I sincerely appreciate the warning, and I do take it to heart.
However, I have a lot of experience working with this sort of thing.
Im not afraid of rebuilding these packs. If I do have to, I will likely use 4 individual larger modules like user "nice" attempted to do.
That being said, the spec sheets for the Valence modules suggests 20A as a standard charge rate, so I would expect them to be able to do that without hearing up.
Excess heat can easily be solved as well by using a charger that has feedback for control to dial back the current if the batteries get got, and adding temperature controlled fans that kick on when the batteries get warm in the same fashion as the cooling fan for the charger or the motor.
Again, I appreciate your reply and on not trying to be rude or shoot your advice down. I'm plotting down uncharted territory. I just wondered if anyone else had done so.