Bosch charger getting very hot

[Jasext]

Recently charged my battery while on the bike using the plug on the frame( normally charge indoors out of the bike) , when it finished charging i unplugged it and noticed the charger was very very hot, much hotter than when charging indoors, it does get a little hot but nothing like this.
I unplugged it as soon as it was full, didn't leave it on for any longer than needed, the bike is a cube 140
Anyone else have this problem or is there an issue with something ?

 

[Beekeeper]

Could be our record-breaking hot weather / high ambient temperature. This will affect how much heat energy can be transferred to the environment from the charger. I doubt it would feel so hot in the middle of winter

 

[MitchF]

I’ve had the same thing, the heat generated is concerning. It’s happened when outside temp is 18 or below.

 

[Mikerb]

I always place the charger on a heat sink.....concrete floor...tile....whatever will help dissipate the heat.

 

[Hill Killer]

My Specialized charger gets red hot like over 60c while in use where as my gen 1 bosch just gets slightly warm 30c.

 

[GrahamPaul]

I've got the Compact 2A Charger. I normally don't charge over 80% because that's supposed to keep the battery happy for longer. The charger gets warm, but nothing noteworthy.

However, when I top the batteries off to 100% (I've got 2 of them), then I reckon I could fry an egg on the charger. It's that last few percent charge when the battery management system is supposed to be reducing the charge level and equalizing the cells. It seems to drive the charger wild. (The batteries don't get hot).

 

[Jasext]

If i charge it off the bike indoors the charger stays ok , its only when charging in the garage which is cooler and through the frame it gets really hot