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Battery Fuse Issues

Old 10-01-15, 01:49 PM
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Question Battery Fuse Issues

I recently installed a 1000 W 48 V ebike motor. Found here: 26" Electric Bike Bicycle Motor Conversion Kit EBike Rear Wheel 48V 1000W | eBay
I used this 48 V 10 ah lithium battery: 48V 10AH Lithium ion Battery Electric Bike Bicycle E Bike Power Pack Scooter | eBay
Everything seems to be connected correctly, but as soon as I start to give it any throttle, I blow the fuse on the battery. I've gone through 3 fuses and it only happens when I am giving the bike throttle. Any ideas how big of a fuse I can use and still be safe or what else might be causing this problem?
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Old 10-01-15, 02:49 PM
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What size fuses are you blowing? The specs on that pack say max current is 15 amps (1.5C) -- and 10 Ah rating is at 12 amps. A 1000 watt motor can draw more than that (flat out maybe 25 amps?, maybe more at times?).

So..you can try a larger fuse, but risk possible BMS damage and/or shortened battery life. What's really needed is a pack that can deliver more current...or a second pack in parallel to share providing the necessary amps.
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Old 10-01-15, 06:48 PM
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I think dilkes nailed it. V power is not regarded highly. Possibly, you need another battery (look at luna cycle).
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Old 10-01-15, 07:14 PM
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Piecing stuff together off of ebay is hard.

what controller are you using, and how much current does it draw? It should say in your specs or on the controller. 15 amps isn't a lot for a motor, although that is what I use. 48V @ 1000Watts is 20 amps.

that battery is a 1C battery, which really isn't going to cut it for an ebike. Best I can tell, you need a controller that won't draw more than 15 amps (and that is pushing it on this battery).
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Old 10-07-15, 04:11 AM
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Many E-bike batteries have a fuse built-in to them that is accessible from the outside. The fuse can fail, just because, but normally if it does, there is a problem with the battery or wiring. The fuse is there to protect your battery and bike from an overload of power that can cause intense heat or fire. A simple voltmeter test can give you a general idea if the battery is holding juice and if the fuse is bad. Most batteries should read about 2-3 volts more than their ratting on the voltmeter. 24, 36, and 48 volt systems are the most common. You will need to know which you have before you proceed.

Some batteries have two wires or connectors where the reading can be taken. Some have more, and that can be the beginning of your confusion. Those extra connections are to feed info about the battery cell condition and balance to the computer, or battery temperature information. They won’t give you the readings you need. If voltmeter tests already sound like more than you understand, you are going to need some help and this post won’t be enough to guide you. So take your list of noted problems and search for a E-bike expert. If you found a bad fuse, replace it with the same exact item and try again. If it blows out again, I would suspect a shorted battery or bad wiring inside the case.
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Old 10-14-15, 04:08 AM
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1000w output motor@ maximum 90% efficiency will draw a minimum of (1000w / .90 = 1111w / 48V = 23.14A)
1000 W 48 V ebike motor can draw 48V >23.14A motor input to produce 1000w motor output.
48 V 10 ah lithium battery is rated for "≤12A", and likely fused, for a "maximum" 15A max output.
Nothing wrong or bad about the battery ...
Motor too big for the battery or battery too small for the motor.

You could up the fuse in the battery but only at the risk of its destruction and the certainty of its greatly reduced lifespan.

Last edited by DrkAngel; 11-03-15 at 04:06 AM.
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Old 10-15-15, 10:27 AM
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I would suspect improper wiring right off the bat. Check connectors and wire colors to be sure they match. A mismatch can easily be the problem but not always. After that suspect a faulty throttle. Test it with a meter if you have any specs/diagram.

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