High Rate BMS from Ping, do I need it?

[Anthony King]

Planning to put eZee hub on cargo bike and ordering a 36V 15A battery from Ping. I am not sure if my needs require the high rate BMS option.

Bicycle will sometimes be heavy (as much as 440 pounds) I have one steep hill to climb (2 miles avg. 4%). I am not looking to go fast.

I've been reading lots on the wiki and forum to try to learn about all the e-bike gear but I must admit I don't exactly understand what a "high rate" BMS is and definitely don't know if I need one.

 

[chvidgov.bc.ca]

The high rate BMS lets you draw more amps from the pack on max power...probably not a good idea, as you would be around 3C on that pack which would stress the battery, if your controller was capable of higher amperages as well.. Your motor doesn't need that many amps anyway. I would get a regular BMS for that motor. Your controller wouldn't match up with a high rate BMS anyway, most likely, as you probably wouldn't have more than maybe a 20 or 25 amp controller for that motor, more likely 20.

 

[Anthony King]

Thank you.

 

[dogman dan]

No, you don't need the high rate bms unless you have a 40 amps controller. And that controller would require a bigger ping.

4% is not that big a challenge to your motor, but 440 pounds will slow you down. When climbing steep hills, try to keep going 15 mph if at all possible. Below that speed, you will be risking melting the motor if the hill is long enough.

Slow on the flats is fine, and little risk, but on the hills you melt the motor if you go too slow for to much time.