Power cuts off because of cold weather?

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phytema   1 mW

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Power cuts off because of cold weather?

Post by phytema » Feb 03 2020 3:35pm

I have a 1500w e-bike with a 60v sinewave controller and a 60v/18ah battery pack. Sometimes when I am using throttle-only (no pedaling), power cuts off and the bike doesn't turn on unless I connect it to the charger. This only happen when I use the bike after I have stored it in a cold underground garage (3-10 Celsius degrees) for 8 hours or so. (e.g. when I get off work)

Is it the cold weather that is causing this or a bad connection/faulty controller?

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MadRhino   100 GW

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Re: Power cuts off because of cold weather?

Post by MadRhino » Feb 03 2020 4:00pm

You need to test methodically, every connection and components. The fault might be the throttle or its connectors, but it could be anywhere on the circuit. Only a logic elimination procedure will tell. And, after the fault is fixed, you need to waterproof all connections on your ebike every year before the winter.
Make it fool-proof, and I will make a better fool.
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phytema   1 mW

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Re: Power cuts off because of cold weather?

Post by phytema » Feb 03 2020 6:24pm

I am all thumbs when it comes to e-bikes so testing it on my own is out of the question.

Given your experience, does this sound like a normal thing for an e-bike/controller/battery pack that's been left out in the cold?

goatman   10 kW

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Re: Power cuts off because of cold weather?

Post by goatman » Feb 03 2020 6:39pm

can you take the battery inside with you where its warm?

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MadRhino   100 GW

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Re: Power cuts off because of cold weather?

Post by MadRhino » Feb 04 2020 12:04am

phytema wrote:
Feb 03 2020 6:24pm
I am all thumbs when it comes to e-bikes so testing it on my own is out of the question.

Given your experience, does this sound like a normal thing for an e-bike/controller/battery pack that's been left out in the cold?
Well, it is hard to diagnose a problem on a bike that is not at hand, and even if I did... if you are not handy enough to test, you would not be handy enough to fix it anyway.

The first thing that comes to mind is a bad contact. But, it also could be that your battery BMS cuts off for some reason: too high power demand or weak cell group, if you have the problem only when you are not pedaling.
Make it fool-proof, and I will make a better fool.
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Street: https://s20.postimg.org/ewrvugywt/Session_04_2015.jpg
Dirt: https://s20.postimg.org/lbqwr55ml/IMG_0157.jpg

phytema   1 mW

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Re: Power cuts off because of cold weather?

Post by phytema » Feb 04 2020 12:22pm

goatman wrote:
Feb 03 2020 6:39pm
can you take the battery inside with you where its warm?
Unfortunately, I can't. The battery pack is too big and too heavy to carry around. Taking it off is very difficult too.

phytema   1 mW

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Re: Power cuts off because of cold weather?

Post by phytema » Feb 04 2020 12:36pm

MadRhino wrote:
Feb 04 2020 12:04am
The first thing that comes to mind is a bad contact. But, it also could be that your battery BMS cuts off for some reason: too high power demand or weak cell group, if you have the problem only when you are not pedaling.
After the bike has been in the cold garage for 8 hours, if I raise the back wheel and give full throttle, the power doesn't seem to cut off (I tried that on/off for a few seconds at a time for 5-10 minutes). And afterwards when I am riding the bike and give it a little throttle (enough to do ~15mph), then the power doesn't cut off either. It is only when I am riding the bike and give it a good amount of throttle (enough to do +20mph) that power cuts off.

I think it might have to do with what you mentioned about "power demand". I have the KT-LCD3 screen. Perhaps there is a setting there to lower/restrict power demand?

HK12K   10 kW

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Re: Power cuts off because of cold weather?

Post by HK12K » Feb 04 2020 12:45pm

phytema wrote:
Feb 03 2020 6:24pm


Given your experience, does this sound like a normal thing for an e-bike/controller/battery pack that's been left out in the cold?
Batteries really don't like being cold so if you can find a way to keep them closer to a comfortable room temperature it would likely help greatly. If it doesn't then it sounds like your pack is in rough shape and is unable to provide the required amperage asked of it and you should find someone who can examine balance and test your pack, or simply start budgeting for its replacement.
Last edited by HK12K on Feb 05 2020 11:47am, edited 4 times in total.

goatman   10 kW

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Re: Power cuts off because of cold weather?

Post by goatman » Feb 04 2020 1:27pm

if theres a plug where you park, id try using a heating pad to keep the battery warm or tarp the bike and use a light bulb under the battery area to keep it warm, just don't burn up your bike. if that solves the problem your battery needs to be tested. look to make sure your balance leads are connected to the bms properly and the connector hasn't vibrated out.

if its cold out and the battery is cold and you crank the throttle the battery wont work good until it warms itself up. cranking throttle on a cold battery can damage the cells

if the display shows battery voltage or a battery bar/gauge if you crank the throttle and the voltage drops right off and cuts out, id say its battery but if the battery gauge or volts only move a little bit and bike shuts down then I don't know

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dogman dan   100 GW

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Re: Power cuts off because of cold weather?

Post by dogman dan » Feb 05 2020 7:39am

Cold enough can do that. If the battery actually freezes, its also very harmful to try to use it.

So you gotta do something, to keep it warmer while you work. You must keep it above freezing.

If its cold, but still not froze, it will still perform very poorly, till it uses up enough of its power in cell resistance, to warm the cells. This will cause enough voltage drop to shut it down.

And as others pointed out, any additional causes of voltage drop. like flaky plugs, will make the problem even worse.

It will help the battery warm back up, if you put some extra insulation around it, best you can. Tea cozy for it, kind of thing, so you at least don't lose any of that warmth.. Then maybe, put a hot water bottle in there an hour before you leave for home.

phytema   1 mW

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Re: Power cuts off because of cold weather?

Post by phytema » Feb 05 2020 6:05pm

Thank you all for your help.

For now I am just giving it enough throttle to go up to ~15mph (on the flat) and I will check the connections between the controller and the battery pack to make sure they are as they should be.

markz   100 GW

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Re: Power cuts off because of cold weather?

Post by markz » Feb 05 2020 8:31pm

Warm the battery up.
Triple check the KT options by methodically going through each one.
Check the connectors making sure they aren't corroded.
Check the wiring itself, from the controller to the motor, controller to throttle, display etc. Make sure there are no nicks, especially from the wires exiting the axle.

You need to learn so:

- Get a digital multi-meter and https://www.ebikes.ca/learn/troubleshooting.html
Could be a throttle issue. I have a current issue of rain, throttle goes full wide open but when I twist the throttle the throttle goes off. I am just too lazy to take 5 minutes and fix it. Its to do with the cheesy chinesium connector. I'd take the connector off, and wire it with no connector, I'd solder the connection and use shrink wrap, then electrical tape it.

Its good to have spares, like a spare throttle and a spare controller, even if its just a cheap $20 unit, but better to have something you can swap out and ride immediately. I have a few sensorless Greentime controllers, so I'd bypass the KT nonsense! I've purchased and ridden a Conhismotor kit, KT display kit, and with all the programmable options sometimes there'd be a hiccup and I'd get frustrated and not deal with it. Dont need no PAS or no Display, screw that jazz.

Since you dont have no spares, you are in a dilemma. Time to suck it up and learn something about your new hobby. Will save you time and money.




OP's quotes below

Sometimes when I am using throttle-only (no pedaling), power cuts off and the bike doesn't turn on unless I connect it to the charger. This only happen when I use the bike after I have stored it in a cold underground garage (3-10 Celsius degrees) for 8 hours or so. (e.g. when I get off work)

After the bike has been in the cold garage for 8 hours, if I raise the back wheel and give full throttle, the power doesn't seem to cut off (I tried that on/off for a few seconds at a time for 5-10 minutes). And afterwards when I am riding the bike and give it a little throttle (enough to do ~15mph), then the power doesn't cut off either. It is only when I am riding the bike and give it a good amount of throttle (enough to do +20mph) that power cuts off.

I have the KT-LCD3 screen.

For now I am just giving it enough throttle to go up to ~15mph (on the flat) and I will check the connections between the controller and the battery pack to make sure they are as they should be.

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