Riding in Winter

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10 mW
Joined
Jun 28, 2024
Messages
22
Location
Poland
Hello!
I have a question regarding battery usage during winter. I assembled a new 20s17p pack with EVE 35V cells. The manufacturer claims the minimum temperature is -20 degrees, and I live in Poland, where the lowest temperatures are usually around -10, -15 degrees. Will riding in such temperatures significantly affect the battery's wear? I commute to work throughout the season. The pack has an ANT BMS, so the cells won't get unbalanced, but I'm more concerned about permanent capacity loss.

Sometimes I have to leave my bike outside for a few hours in subzero temperatures.
 
Your main problem is charging at very low temperatures. At -10C you can expect the amperage output the 25% of what it is at room temperature, the only mitigation against this is to oversize your battery amp hours or output if you'll be riding in such cold temps.

An electric bike would be happier left indoors for a lot of reasons!
 
Your main problem is charging at very low temperatures. At -10C you can expect the amperage output the 25% of what it is at room temperature, the only mitigation against this is to oversize your battery amp hours or output if you'll be riding in such cold temps.

An electric bike would be happier left indoors for a lot of reasons!
What I mainly want to know is whether riding in winter, when the battery is kept at -10°C, will have a significant impact on capacity loss? I will, of course, try to charge it in a warm room. I know there will be a higher SAG, etc. but what I'm concerned about is the permanent loss of capacity.
 
I don't think it will create capacity loss permanently but your LVC will trip a lot sooner if you haven't overspecced it per the kind of load you'll be putting on. The capacity loss will be temporary.

It's large amounts of heat and overdischarge/overcharge that really kill a battery.
 
So, I've thought about this but only ride 20 minutes a day for fun;
I would heat the battery pack with rechargeable hand (?) warming pads ( charged daily and separately used as required in Winter ) and cover it with a neoprene insulation sleeve to preserve it's efficiency throughout it's operating range and life since they like warm.
 
Is the battery pack removable? If so, you could keep it inside, and bring it out when you're ready to ride. It'll retain its indoor temp for your 20 minute rides without you having to warm it.
 
Is the battery pack removable? If so, you could keep it inside, and bring it out when you're ready to ride. It'll retain its indoor temp for your 20 minute rides without you having to warm it.
Nope.
 

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Art; I would make a custom bespoke water resistant rechargeable electric vest for your bike somehow
) wrap ?( with a separate appropriate battery ( or batteries while at work ) Do you get cold riding?.
Salt and mud protection will be advantages for instance.
Maybe a nice "S" on the side - because it looks Super.
 
Art; I would make a custom bespoke water resistant rechargeable electric vest for your bike somehow
) wrap ?( with a separate appropriate battery ( or batteries while at work ) Do you get cold riding?.
Salt and mud protection will be advantages for instance.
Maybe a nice "S" on the side - because it looks Super.
Everything is normally sealed and hermetically closed. No additional covers are needed, the photo was taken with the housing removed. The package is also hermetically sealed. I ride in winter, the whole season.
 

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Hello!
I have a question regarding battery usage during winter. I assembled a new 20s17p pack with EVE 35V cells. The manufacturer claims the minimum temperature is -20 degrees, and I live in Poland, where the lowest temperatures are usually around -10, -15 degrees. Will riding in such temperatures significantly affect the battery's wear? I commute to work throughout the season. The pack has an ANT BMS, so the cells won't get unbalanced, but I'm more concerned about permanent capacity loss.

Sometimes I have to leave my bike outside for a few hours in subzero temperatures.
For storage, low temperatures are actually optimal.

For charging, make sure to only charge when the pack has been stored a while inside.
 
For storage, low temperatures are actually optimal.

For charging, make sure to only charge when the pack has been stored a while inside.
Semi off-topic then: I usually dismantle my 110-pound lithium ion battery off my motorcycle, and store it in my basement for 3 months. Are you suggesting that I should keep it upstairs and cold (sheltered from elements, of course)?
 
Semi off-topic then: I usually dismantle my 110-pound lithium ion battery off my motorcycle, and store it in my basement for 3 months. Are you suggesting that I should keep it upstairs and cold (sheltered from elements, of course)?
Yes, unless temperatures drop below -20C for a long time.
There's a NASA article analysis calendar life at 0C (LG MJ1) showing that at these temps, calendar life is practically infinite.

Below -20C is where it starts getting tricky since graphite anodes start behaving weirdly at that point.
 
For storage, low temperatures are actually optimal.

For charging, make sure to only charge when the pack has been stored a while inside.
How does this relate to driving in -10/-15°C? Doesn't it cause any permanent loss of capacity or anything else?
 
How does this relate to driving in -10/-15°C? Doesn't it cause any permanent loss of capacity or anything else?
That's a very interesting question.
There haven't been a lot of scientific articles on the subject.

We know that low temperature charging greatly hurts battery lifetime, but we don't know what happens to long term life if you charge at ambient temperatures and discharge at sub ambient temperatures. I'll look more into it.

In the meantime, I'd recommend just cutting your battery current by half on your vehicle to keep its range :p
 
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