Glens carzy ebike
10 mW
- Joined
- Aug 3, 2019
- Messages
- 23
Is it ok to charge a hot battery at 5 amps or is it better to let it cool down for an hour ?
Is it ok to charge a hot battery after a long ride at 5 amps?
- Thread starter Glens carzy ebike
- Start date
markz
100 TW
It depends on what the charge rate for the battery is.
Better to let it cool down, but it depends.
Better to let it cool down, but it depends.
Glens carzy ebike
10 mW
- Joined
- Aug 3, 2019
- Messages
- 23
5 amps
wturber
1 MW
Glens carzy ebike said:
I'm pretty sure he was wondering was the charge rate per cell and then would want to know what kind of cells. In other words compare what you are doing with the actual or typical cell specs.
If the battery is hot, you have the wrong battery for your application.
You should size the battery to provide the current your system needs without significant voltage sag, without creating significant heat. Both are indicators of insufficient batteyr capability.
And no, you shouldn't charge a hot battery at all.
If it's getting hot while in use, you've already created a fire risk while in use.
If it's getting hot while charging, you've created a fire risk while charging.
If it's already hot before charging, then the extra heat from charging increases the fire risk.
Your choice, but I hope I don't live near you if you do.
You should size the battery to provide the current your system needs without significant voltage sag, without creating significant heat. Both are indicators of insufficient batteyr capability.
And no, you shouldn't charge a hot battery at all.
If it's getting hot while in use, you've already created a fire risk while in use.
If it's getting hot while charging, you've created a fire risk while charging.
If it's already hot before charging, then the extra heat from charging increases the fire risk.
Your choice, but I hope I don't live near you if you do.
Volt_Ampere
10 W
- Joined
- Apr 18, 2018
- Messages
- 76
Let it cool down to ambient before charging. Too cold is below freezing so don't put it in the freezer.
markz
100 TW
This is an interesting article, though its a123 you may find of use or not depending on your chemistry.
Lots of temperature related info with my quick search of "temp"
https://www.buya123products.com/uploads/vipcase/b24d4f5b63934c59d43e93b3bb4db60a.pdf
I was actually trying to find a NASA battery pdf file here on ES that I remember reading.
Lots of temperature related info with my quick search of "temp"
https://www.buya123products.com/uploads/vipcase/b24d4f5b63934c59d43e93b3bb4db60a.pdf
I was actually trying to find a NASA battery pdf file here on ES that I remember reading.
dogman dan
1 PW
Define hot. In my garage, room temp might be 110F. Not ideal to charge it in a place that hot, but one cant exactly wait till fall to charge it again.
But if you can't hold that thing in your hand, then no, don't charge it till it cools enough to hold it. For most folks, that's around 140F or so. And it might be an inconveniently long wait for a larger battery to cool to ambient temp, so if that is the case, charge it very warm, but not so hot you can't hold it in your hand.
And as said above, if its getting that hot discharging it, the problem will go away pretty soon when you kill the pack.
But if you can't hold that thing in your hand, then no, don't charge it till it cools enough to hold it. For most folks, that's around 140F or so. And it might be an inconveniently long wait for a larger battery to cool to ambient temp, so if that is the case, charge it very warm, but not so hot you can't hold it in your hand.
And as said above, if its getting that hot discharging it, the problem will go away pretty soon when you kill the pack.
Ford Prefect
1 W
I am rather unsure what the weather should be like in New Zealand in August. Maybe the battery got warm because he was riding outside, in the sun? 
MadRhino
100 GW
Any batteries, any size, any chemistries...
None like being charged or discharged when hot.
Some you are just killing them slowly, some will leak gas and start a fire.
The best indicator of battery health is heat, although most EVs are only equipped to monitor voltage and Amps.
None like being charged or discharged when hot.
Some you are just killing them slowly, some will leak gas and start a fire.
The best indicator of battery health is heat, although most EVs are only equipped to monitor voltage and Amps.
Ford Prefect
1 W
Yes I know, it is middle of winter. basically a February of the northern hemisphere. We get anything between -20°C and +20°C in February. Even simultaneously in Germany. When I was in NZ as a teenager they were warning because of the hole in the Ozon layer.
But whatever. Not the point here. Sorry…
But whatever. Not the point here. Sorry…
There is a critical distinction between "hot batteries" due to thermal / chemical reactions caused by high discharge rates
and regular old hot weather, or high **ambient** temps for other reasons
It is the former cause where you need to wait, let things "settle down internally" before inflicting further stress by charging, especially if at a high C-rate.
The latter, ambient conditions, is not conducive to longevity whether in storage or in use cycling, but is not immediately damaging, and no problem for regular charging.
and regular old hot weather, or high **ambient** temps for other reasons
It is the former cause where you need to wait, let things "settle down internally" before inflicting further stress by charging, especially if at a high C-rate.
The latter, ambient conditions, is not conducive to longevity whether in storage or in use cycling, but is not immediately damaging, and no problem for regular charging.
