I love EV. Drive an electric car and have several electric bicycles and skateboards, but I would love to convert a motorcycle to electric. I plan to start small to get my feet wet so I purchased an electric motorcycle with a lead acid battery and 2000w hub motor. I want to upgrade the hub motor to the QS 8000w and make my own 72v lithium battery pack. 20s12p configuration. Doing that I should be able to fit 2 identical battery packs in the battery box. My questions are 1) does each battery get its own BMS or do I wire them together in parallel? 2) I live in an area with tons of level 2 chargers with j1772 connections. Is there anyways to add the port to be able to charge the bike at these stations?
Beginner needing some helps
- Thread starter KemoH
- Start date
ZeroEm
1 MW
I'm all electric, enjoy my e-Car and e-Bikes.
Why do you want two packs?
One BMS and one battery would be better. Simple answer but nothing is never simple.
Yes you can setup a j1772 charge connection. Will need to carry your charger/s with you.
Things to think about. If you want to use Level 2 public charge stations. Need a fast charging battery with a charger to match. You did not state what cells you are planning to use. I would give this some thought. One large battery would be best with large high amp cells. You will need them with a big motor.
18650 vs prismatic
How I charge my ebike from J1772
There is more information if you need it.
Why do you want two packs?
One BMS and one battery would be better. Simple answer but nothing is never simple.
Yes you can setup a j1772 charge connection. Will need to carry your charger/s with you.
Things to think about. If you want to use Level 2 public charge stations. Need a fast charging battery with a charger to match. You did not state what cells you are planning to use. I would give this some thought. One large battery would be best with large high amp cells. You will need them with a big motor.
18650 vs prismatic
How I charge my ebike from J1772
There is more information if you need it.
Millhouse_5
1 W
- Joined
- Nov 27, 2020
- Messages
- 62
Make sure your chassis can handle a 4x increase in power first.
I have a bike that came with a 1500w motor that I swapped out to a 3000w and personally I wouldn't put any more power in it mostly due to the chassis.
if your bike is a similar quality to a typical motorcycle you shouldn't have a problem running at highway speeds.
If you specifically want two batteries for easy swapping out and charging then the way to go will be with a fully independent dual BMS system. But that's the only real case where you'd be doing that. Otherwise it's best to just make one large battery back managed on one BMS. The more parts you add in any system, the more points of failure there are. Simple really is better.
I have a bike that came with a 1500w motor that I swapped out to a 3000w and personally I wouldn't put any more power in it mostly due to the chassis.
if your bike is a similar quality to a typical motorcycle you shouldn't have a problem running at highway speeds.
If you specifically want two batteries for easy swapping out and charging then the way to go will be with a fully independent dual BMS system. But that's the only real case where you'd be doing that. Otherwise it's best to just make one large battery back managed on one BMS. The more parts you add in any system, the more points of failure there are. Simple really is better.
Thank you both for your reply’s and input. I think I didn’t explain well enough about the 2 packs. The battery box only fits a 20s12p vertically so the “second pack” was there to just help extend the range. From your replies, I can tell a single BMS is better and just wire the 2 packs together. That’s what I was thinking to do but just wanted to make sure. It is a motorcycle chassis so it should be able to handle the increased power.
My assumption that 18650 cells are created equal is flawed I see and needs further research. If I wanted to fast charge the bike, what qualities in a 18650 and charger should I be looking for?
My assumption that 18650 cells are created equal is flawed I see and needs further research. If I wanted to fast charge the bike, what qualities in a 18650 and charger should I be looking for?
ZeroEm
1 MW
Two packs then two BMS. The issue would be that the batteries would not be connected at the cell/group level.
