Is the BMS supposed to get quite warm/hot whilst charging?

[joeworrall]

48v 10ah duct-tape LiFePO4 battery
5amp fast v-power charger

the BMS on my pack get quite warm whilst charging, doesnt warm up much/at all while discharging (ive never really gone out of my way to check its temperature while discharging)

It came in a double thick pouch that has 130 degrees Celsius written on it, im assuming this is the temperatures it can withstand.

Is this normal?

 

[grindz145]

It will heat up while charging, and depending on the FETs they use it may heat up more than discharging. I would double check the rated charge capability to be safe. It all depends how much its heating up

 

[joeworrall]

The charger came supplied with the battery, the BMS also came already pre-wired up to the battery so im pretty confident its okay based on this then It is still touchable (can hold it for as long as needed and it doesnt burn my hand) through the casing, just feels very warm. thanks.

 

[Russell]

If you have a bleeding type BMS then most of the heat will be generated near the end of the charge cycle and for perhaps up to 1/2 hour after you remove the charger and is from the resistors draining excess voltage from each cell as they are balanced.

Here is a picture of the BMS I have with the resistors circled. These get quite hot while they are bleeding off the excess voltage but it's normal.




-R

 

[The Mighty Volt]

Any flow of electric current has the potential to generate heat.

 

[BLUESTREAK]

Ihave 2 CAMMY-CC 48 volt 20amp duct tape packs and the BMS only get warm when charging,yes this is mormal.

 

[dogman dan]

Yes it's normal, especially charging at 5 amps vs 2 amps or less. The amount of heat varies with the particular bms. On my two pings, the v1 bms gets hot enough to scorch the shrink wrap while balancing, but can balance pretty quickly. On the V2 bms the balancing takes place at a lower current level, and that bms never gets past warm while balancing or charging.

If your bms is the hot kind, then don't smother it in a bag or padding for a box while you charge. Give the bms some breathing room.