Increasing power without changing motor

[Kaio_]

My bike has a 1200W rear hub motor (tops at ~1388W) that I'm running at 52v at probably around ~25A. All from an Ebikeling kit I want to upgrade.

I purchased a 72v 20Ah battery w/ 50A BMS. Should I just spend the money for a 3000W kit, or can I just upgrade the controller alone to 72v 30A~40A to get 2000W? Although I'm not sure how overbuilt these motors are.

 

[JackFlorey]

Should I just spend the money for a 3000W kit, or can I just upgrade the controller alone to 72v 30A~40A to get 2000W? Although I'm not sure how overbuilt these motors are.

1) If it doesn't have one now, put a thermistor in so you can monitor temperature. Then you will know for sure.
2) If you want a bit more power, consider Statorade to improve thermal performance. Most hub motors are compatible.

 

[dogman dan]

Just remember, its great fun to melt your motor. You don't have a 1200w motor, you have a 500w rated motor that is near its max, which is about 1500w. Sure, you can run double the max, briefly. Statorade will help for sure.

Then after you melt your motor, get the big heavy motor that can handle 3000-5000w. Its all part of the fun, and the progression. By then you will want moped tires and rims anyway.

 

[mxlemming]

My bike has a 1200W rear hub motor (tops at ~1388W) that I'm running at 52v at probably around ~25A. All from an Ebikeling kit I want to upgrade.

I purchased a 72v 20Ah battery w/ 50A BMS. Should I just spend the money for a 3000W kit, or can I just upgrade the controller alone to 72v 30A~40A to get 2000W? Although I'm not sure how overbuilt these motors are.

This motor looks identical to the voilamart one i bought. They can take way more power than it says. I feed mine from a FOC controller I built and it takes 60A phase without getting hot. Gets vaguely warm if i run that current flat out for several minutes. Takes me up to about 45mph on a 20s battery.

It's never going to be a qs205 50h but you can have much more fun but swapping out the piddly power big useless control box.

 

[Eastwood]

Then after you melt your motor, get the big heavy motor that can handle 3000-5000w. Its all part of the fun, and the progression. By then you will want moped tires and rims anyway.

Yep this describes many people situations :wink: Including myself except I never melted any motors.

 

[E-HP]

I purchased a 72v 20Ah battery w/ 50A BMS. Should I just spend the money for a 3000W kit, or can I just upgrade the controller alone to 72v 30A~40A to get 2000W?

Get a controller that will later support an upgrade to the 3kW motor and/or beyond. It should be programmable and have a wide voltage range. That way, no matter where you take things, the controller will be up to it. It will also allow you more flexibility with your current setup, since you can experiment with different voltage levels, and all the other options you'll have. Unless you have another use for your motor, then why waste it?

I like a controller with a 3 position switch, since it creates some discipline that my throttle hand doesn't have. I rode around all day today on low, which limits the output to 1440W continuous and 3200W peak. Still feels fun since the 3kW provides decent acceleration, while not using up battery unnecessarily. Medium level would allow about 5kW even when accelerating mildly. This is with a 1000W ebay motor with Statorade. Basically, that 20Ah battery won't last long, since little blips of the throttle will let a lot of power flow, and even though the burst of speed are fun, they use up a lot of charge. A 3 position switch and/or cycle analyst can help get more range out of the battery.