Will it matter? Moving from 48v to 36v battery.

ColinB

100 W
Joined
Jun 29, 2011
Messages
171
Location
British Columbia, Canada
I currently run a 48v battery and use my Cycle Analyst to limit the power draw to ~ 600w. And my bike gearing limits my pedaling to 30-40km/hr. So I'm not using the maximum power and speed from my motor/battery, but that's how I'm using it.

If I move to a 36v battery, will it matter? If I was not limiting power with the Cycle Analyst, then yes, I'd loose top speed and power. But since I normally limit power and speed that is within reach of the 36v battery, I don't think I'll notice a lot of difference.

- A 36v battery will still get me to 41km/hr, faster than I can pedal (for extended periods.)
- The 36v battery is good for over 1000 watts, more than my set limit.

Will hill climbing power change? I don't think so, since I use the CA to limit power. The ebikes.ca motor simulator suggests I will have virtually the same speed and wheel torque for a given battery power draw.

If I disregard my 600w limit, then the 48v system is a good chunk faster. But I think for my riding style, moving to a 36v battery won't matter.

Thoughts? Am I missing something?

Colin
 
ColinB said:
If I disregard my 600w limit, then the 48v system is a good chunk faster. But I think for my riding style, moving to a 36v battery won't matter.

Thoughts? Am I missing something?

Colin

I think you'll accelerate half as fast once you're past the midrange of your speed due to the loss of torque in the range where the 600W cap doesn't apply. So not as quick, or less torque when climbing when your motor is operating in that (upper) range.

https://ebikes.ca/tools/simulator.html?motor=MG60_500&batt=B4816_GA&cont=cust_6_18_0.03_V&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=0&wheel=25i&mass=110&cont_b=cust_6_18_0.03_V&motor_b=MG60_500&batt_b=B3617_35E&wheel_b=25i&mass_b=110&hp_b=0&bopen=true

Move the sliders over to the range where the torque curves diverge and you can compare the acceleration in the table below. It will likely be pretty noticeable through a seat of the pants test.
 
Remember if both batteries are the same Ah then you will lose distance/range. Volts is mostly considered speed. Most would go with a motor with more turns to get the speed down, not sure this is an option for you. 48v is the most common battery, would stick with it and use the CA not limit the battery. Always want more battery not less.
 
Hope your controller will run at 36V. Since you have a CA, you must know what's going on. All of my controllers, except for the internal one in my BBS02 mod drive, will run on 10S or 13S. but some of them aren't rated for anything above 50V.
 
Back
Top