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Ebike wattage

Joined
Sep 21, 2023
Messages
16
Location
Waterloo
Hello!

Okay so, this might sound odd but how much SHOULD I be using on a 48v 1500w direct drive motor?

I'm currently running a programmed 48v controller. Pulling in 45amps.
With the 48v 1500w direct drive rear motor.
On a 52v 19.2ah battery capable of pushing 45amps.

I've read that I might be pulling to many amps for the rear motor to handle.
I've opened it up and installed statorade and it helped alleviate the heat somewhat. Maybe I should install the hub sinks as well.....


But should I just drop the amps in the controller setting to lower than 45amps?

Or

Have faith in the statorade + hub sink, set up.

Any input is welcomed. Even how to make banana pancakes
 
What kind of plug do you have between the motor and the controller? Different plugs have different amp ratings.

Make sure your motor phase wires have no hard bends. Nice 90 degree sweeping elbows. The hard bends will stress the wire and heat will build up at that exact spot. Melting the insulation.

Fully charged at 58v and 45 amps, you’ll pull 2600 watts. I’d be concerned about heat, not just at the motor (which you have addressed), but all the connectors. Aside from identifying that motor plug you have, also note and share the other connections on the phase wires, if any, as well as the gauge of phase wires.

From my experience, I had heat build up on my phase wires, this was due to hard bends and 15 amp rated banana plugs. I resolved both sides and my phase wires do not get hot.

For reference, I have a 48v 25a controller feeding a 1000w rear hub Shengyi. The motor has a Z910 plug and 16AWG phase wires.

Also, I can’t help you with banana pancakes, but whatever you do, don’t use a box recipe. My kids love my plain pancakes from scratch. I use fresh eggs from our chickens. Maybe I can email you some when I make them next. :)
 
But should I just drop the amps in the controller setting to lower than 45amps?

Or

Have faith in the statorade + hub sink, set up.

Any input is welcomed. Even how to make banana pancakes
The concern is almost always heat, which statorade and sinks will help with; but it's sort of like putting gas in your car without a fuel gauge. The gas will let you driver further, but you don't know how much further. You can operate on faith, or be informed, which would be to install a temp sensor. That will allow you time to back off on the throttle, of if you have a controller that can roll back power automatically when the motor hits a certain temp, then that will help if you aren't paying attention.
Adding another wire to the bundle going through the axle may be a challenge, but once you have a way to monitor the temps, any related anxiety disappears, knowing it's all under your control.

Here's a case where I wasn't paying attention. I've done a lot of temp testing of my motor, but this day I was testing voltage sag, and forgot about watching my temps. You can see the high temp roll back happen at 1:10 of the video when the power suddenly drops by 1000W or so. I still didn't figure it out until it continued to roll back power, at which point I said "Oh crap" and pulled over to let the motor cool.
 
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What kind of plug do you have between the motor and the controller? Different plugs have different amp ratings.

Make sure your motor phase wires have no hard bends. Nice 90 degree sweeping elbows. The hard bends will stress the wire and heat will build up at that exact spot. Melting the insulation.

Fully charged at 58v and 45 amps, you’ll pull 2600 watts. I’d be concerned about heat, not just at the motor (which you have addressed), but all the connectors. Aside from identifying that motor plug you have, also note and share the other connections on the phase wires, if any, as well as the gauge of phase wires.

From my experience, I had heat build up on my phase wires, this was due to hard bends and 15 amp rated banana plugs. I resolved both sides and my phase wires do not get hot.

For reference, I have a 48v 25a controller feeding a 1000w rear hub Shengyi. The motor has a Z910 plug and 16AWG phase wires.

Also, I can’t help you with banana pancakes, but whatever you do, don’t use a box recipe. My kids love my plain pancakes from scratch. I use fresh eggs from our chickens. Maybe I can email you some when I make them next. :)


Then should I just drop the Amps in the controller settings to just pull 36amps instead?
Like what's the best setting for a 48v 1500w rear hub motor. So the motor can reach a thermal equilibrium without having to back off the throttle all the time.

And I use an XT60 connector. Plus this is how the connectors sit
 

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The concern is almost always heat, which statorade and sinks will help with; but it's sort of like putting gas in your car without a fuel gauge. The gas will let you driver further, but you don't know how much further. You can operate on faith, or be informed, which would be to install a temp sensor. That will allow you time to back off on the throttle, of if you have a controller that can roll back power automatically when the motor hits a certain temp, then that will help if you aren't paying attention.
Adding another wire to the bundle going through the axle may be a challenge, but once you have a way to monitor the temps, any related anxiety disappears, knowing it's all under your control.

Here's a case where I wasn't paying attention. I've done a lot of temp testing of my motor, but this day I was testing voltage sag, and forgot about watching my temps. You can see the high temp roll back happen at 1:10 of the video when the power suddenly drops by 1000W or so. I still didn't figure it out until it continued to roll back power, at which point I said "Oh crap" and pulled over to let the motor cool.

Should I just lower the amps on the controller and give the stator some breathing room.

Like 36amps should be good enough for a 48v 1500w motor I feel.
 
So the motor can reach a thermal equilibrium without having to back off the throttle all the time.
You will never ride your bike in a manner where the motor will reach thermal equilibrium so you really need a better idea on how your motor builds and sheds heat. The motor can quickly get to 100C under the right/wrong conditions, and the motor case may only feel lukewarm, and it could be cooling back down even before the case heats up. A 1500W motor can take a pretty huge amount of power, but efficiency of the motor will determine how fast it heats up relative to a less/more efficient motor. It all works out if you can monitor and keep the temps in check. I just went down to the taco truck and back, and just riding casually I hit 7kW somewhere along the route, but the temps stayed normal; but if I'm thrashing the bike even on flat ground for 20 minutes, it can easily get up into the high 90C's.
You can use the Grin motor simulator to get an idea of what a direct drive motor does under different conditions with respect to heat, by adjusting the hill grade and other parameters.
If you're not climbing monster hills for 20 minutes at a time, then statorade alone will likely be good enough. I ran my old 1000W ebay hub with just statorade for thousands of miles and lots of hills and it was still going strong until I upgraded it.

BTW you can still melt your motor even running 36A if you are running it an inefficient range where more energy is being dumped to heat.
 
How hot is the motor getting? Can you check it with a IR thermometer? Can you place your hand on the motor?
Uhh it gets fairly warm. When I added the statorade temps were a little better. And this is by hand touching.

And I've found the battery doesn't heat up as much.

However it did burn througg the little amount of statorade when installed it.

Now I added a little more to the magnets. But it seems to be heating up a bit more.

And im gonna reinstall the hub sinks.

I'm thinking it's a too much amps issue.
 
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