Power cuts off because of cold weather?

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?

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.

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?

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

phytema said:

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?

Click to expand...

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.

goatman said:

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

Click to expand...

Unfortunately, I can't. The battery pack is too big and too heavy to carry around. Taking it off is very difficult too.

MadRhino said:

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.

Click to expand...

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?

phytema said:

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?

Click to expand...

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.

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

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.

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.