offgriddave
Solar Enthusiast
- Joined
- Feb 14, 2020
- Messages
- 225
I was exploring some ideas and came across people building their own electronic dirt bikes
Some of the kits talk about 3000w and 5000w motors.
Here's a sort of a dump of various specs and data on motor kits, over at endless sphere
endless-sphere.com
Check out some of the requirements
----
Life Time of QS Motor & Warranty of Sample
The Life Time of motor depends on usage.
For general usage, it's about 3-5 years, and it could be 5-7 years if it work in good condition.
For testing and abusing usage, the lifetime will decrease accordingly.
E.g., For 3kW V2/V3 motor, the peak power could be 6kW (2 times of rated power).
Situation 1:
We suggest peak 70-80A battery current for general usage (72V). It's most stable configuration & longest life time.
Some EV enthusiast adjust it to be 150A, the output power is far more than 6kW peak. QS Motor could also work,
which might not as stable as former situation. For a long time in high current/power, the motor might over heat & even burnt.
We strongly suggest to install Thermic Probe (e.g. KTY 83/122), so that controller will protect motor due to the temp inside of motor.
Situation 2:
The peak speed of 1pc 3kW motor is 80KPH in 72V(for e-scooter).
Some EV enthusiast adjust it to be 96V, the max speed might be 100KPH, the continuous output power is far more than 3kW rated (maybe equal to 5-6kW).
QS Motor could also work, which might not as stable as it in 72V.
We call it over voltage/abusing usage, the life time might be shorter, and V3 will work better than V2.
----
got me thinking, how would one even go about building an e-dirt bike battery? You would need small compact and high voltage high amperage cells arranged in a very special way. I tried to research this more, but couldn't find anyone giving the details on their custom battery build
From above, 72v at 70 amps. For Lithium Ion 18650, nominal 3.7 -- 72v is about 19S. A single row of, lets say top of the line Panasonic 9w, would yield 171wh. Enough to power a 3000w motor for 2 minutes! For twenty minutes I calculate over a hundred batteries. Might be do-able, but the range would be low.
Do they even make a 19S BMS? Would you have to build a custom BMS? Is there some universal BMS system out there you could adapt?
Curious DIY'ers, How would you go about tackling this battery build?
Some of the kits talk about 3000w and 5000w motors.
Here's a sort of a dump of various specs and data on motor kits, over at endless sphere
QSMOTOR,0.5-12kW Electric Hub Motor & Mid Drive Motor Manufacture China
QS Motor Electric In Wheel Hub Motor List Official Web: http://www.cnqsmotor.com/en/ Facebook: https://www.facebook.com/cnqsmotor/ There are many store sale QS Motor and Electric Motor Kits on aliexpress, I would like to make it more clearly for better understanding. SiAECOSYS (SIA in short) is...
endless-sphere.com
Check out some of the requirements
----
Life Time of QS Motor & Warranty of Sample
The Life Time of motor depends on usage.
For general usage, it's about 3-5 years, and it could be 5-7 years if it work in good condition.
For testing and abusing usage, the lifetime will decrease accordingly.
E.g., For 3kW V2/V3 motor, the peak power could be 6kW (2 times of rated power).
Situation 1:
We suggest peak 70-80A battery current for general usage (72V). It's most stable configuration & longest life time.
Some EV enthusiast adjust it to be 150A, the output power is far more than 6kW peak. QS Motor could also work,
which might not as stable as former situation. For a long time in high current/power, the motor might over heat & even burnt.
We strongly suggest to install Thermic Probe (e.g. KTY 83/122), so that controller will protect motor due to the temp inside of motor.
Situation 2:
The peak speed of 1pc 3kW motor is 80KPH in 72V(for e-scooter).
Some EV enthusiast adjust it to be 96V, the max speed might be 100KPH, the continuous output power is far more than 3kW rated (maybe equal to 5-6kW).
QS Motor could also work, which might not as stable as it in 72V.
We call it over voltage/abusing usage, the life time might be shorter, and V3 will work better than V2.
----
got me thinking, how would one even go about building an e-dirt bike battery? You would need small compact and high voltage high amperage cells arranged in a very special way. I tried to research this more, but couldn't find anyone giving the details on their custom battery build
From above, 72v at 70 amps. For Lithium Ion 18650, nominal 3.7 -- 72v is about 19S. A single row of, lets say top of the line Panasonic 9w, would yield 171wh. Enough to power a 3000w motor for 2 minutes! For twenty minutes I calculate over a hundred batteries. Might be do-able, but the range would be low.
Do they even make a 19S BMS? Would you have to build a custom BMS? Is there some universal BMS system out there you could adapt?
Curious DIY'ers, How would you go about tackling this battery build?
