500w or 1000w Ebike Kit?
02-24-18, 10:15 AM
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500w or 1000w Ebike Kit?
I'm wanting to build an ebike from a conversion kit. I'm planning on using some 40 volt lithium batteries I already have. I'm wondering if I should go with a 500w 36v kit or 1000w 48v kit? I like the idea of having the extra power if I decide to upgrade the batteries in the future, but would my 40v batteries work with the 1000w kit?
02-24-18, 01:29 PM
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Depends on your controller. I own a couple that only work at one voltage and have others that will operate on 36V or 48V. Controllers needs to have a low voltage minimum (LVC) where it shuts off to prevent battery damage. Controllers that use LED consoles usually have a fixed LVC via the circuit design, Controllers that use LCD consoles often are able to set LVC automatically on powerup or by user input.
Voltage for the motor doesn't matter. It's the maximum current that determines its power output, although it will spin faster with more voltage.
I would select the controller on physical size, and current/voltage capability. Here are four I have, rated by seller at 800W, 500W, 250W and 500W, but it's the current that matters. The biggest one is 25A. The one in the middle is 22A, and both will take 36-52V. The little ones are rated for 36V 10A ane 48V 14A, but I found 10A too weak for acceleration. It's possible to get them in that size with 20A capability. I have one that will do that, except it's on a bike and not available for a group photo.
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Voltage for the motor doesn't matter. It's the maximum current that determines its power output, although it will spin faster with more voltage.
I would select the controller on physical size, and current/voltage capability. Here are four I have, rated by seller at 800W, 500W, 250W and 500W, but it's the current that matters. The biggest one is 25A. The one in the middle is 22A, and both will take 36-52V. The little ones are rated for 36V 10A ane 48V 14A, but I found 10A too weak for acceleration. It's possible to get them in that size with 20A capability. I have one that will do that, except it's on a bike and not available for a group photo.
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02-25-18, 08:33 AM
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A 48v controller won't work, because it'll think your battery is flat and initiate the safety cut out to preserve a low battery.
Your battery is about right for a 36v controller.
Your battery is about right for a 36v controller.
02-26-18, 01:22 PM
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Kind of doubtful your 40v batteries have the current capacity for an e-bike - unless you have some pretty heavy duty batteries.
That said - the power is a function of voltage x current. 40 volts needs 25 amps to get to 1000 watts. Can your battery do that without overheating or destroying its life span?
As for motor - it doesn't make too much difference. Power doesn't come from the motor - it comes from the battery and controller.
And yeah - controllers are made for 36 v or 48v batteries. 40 is in a nomands land, although it is going to be pretty close to a 36v. Is your battery going to be compatible with the LCV of a 36 v battery, or will that drain it too much???
That said - the power is a function of voltage x current. 40 volts needs 25 amps to get to 1000 watts. Can your battery do that without overheating or destroying its life span?
As for motor - it doesn't make too much difference. Power doesn't come from the motor - it comes from the battery and controller.
And yeah - controllers are made for 36 v or 48v batteries. 40 is in a nomands land, although it is going to be pretty close to a 36v. Is your battery going to be compatible with the LCV of a 36 v battery, or will that drain it too much???
02-27-18, 01:37 PM
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The other guys are correct. Your batteries need to be discussed,
Toolmakers often market their 10S lithium 36 volt batteries as 40 volt batteries. I have some Ryobi 40V tool batteries, The bigger one is labelled 5AH. The smaller one, they're too embarrassed to say, but maybe 2AH. They're for weedwhackers and lawn mowers. Ryobi makes a good weedwhacker, but it's pretty heavy. That's why I had them.
I can run my 500W fatbike on one, because its controller will run on 36V. If I use the throttle, it takes too much current and resets the battery circuits. These are only useable on my 36V motor bike. Six miles on the little one, if you're interested.
I've heard some of the other tool batteries are more powerful.
Toolmakers often market their 10S lithium 36 volt batteries as 40 volt batteries. I have some Ryobi 40V tool batteries, The bigger one is labelled 5AH. The smaller one, they're too embarrassed to say, but maybe 2AH. They're for weedwhackers and lawn mowers. Ryobi makes a good weedwhacker, but it's pretty heavy. That's why I had them.
I can run my 500W fatbike on one, because its controller will run on 36V. If I use the throttle, it takes too much current and resets the battery circuits. These are only useable on my 36V motor bike. Six miles on the little one, if you're interested.
I've heard some of the other tool batteries are more powerful.
