Help Appreciated with Battery Charger.

Thread Starter

Novice Repairer

Joined Apr 26, 2021
7
I have recently had problems with my battery charger,as soon as I put it on it starts to charge very briefly then cuts right out. Having examined it I find 2 resistors have burnt out, I want to replace them but need guidance as to what number resistor to replace them with. I woulIMG_0562.jpgIMG_0559.jpgIMG_0559.jpgd appreciate any help with this problem please.Photos below hopefully will help.
 

Yaakov

Joined Jan 27, 2019
3,523
The resistors clearly got very hot, but that's not a surprise. They are 100 milliohm resistors. If they are in part of a very low resistance load they are going to get very hot.

But, if you put a meter on them or even a continuity checker and they are not open, they are not "burnt".
 

Dodgydave

Joined Jun 22, 2012
10,050
I would say at a guess looks like 0.1 ohms 3W each, they're both in parallel and are in series in the batt negative lead. So assuming it takes 10A at full each resistor would be getting 2.5W heat @5A .
Also looks like it's been repaired before there is a white link on the switch mode chip on the right.
 
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