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Electronics => Electronics => Topic started by: SeagullOne on August 28, 2009, 05:40:09 PM

Title: Blown Fuse? Electronics still work?
Post by: SeagullOne on August 28, 2009, 05:40:09 PM

Well, I was charging a 6V 10Ah battery pack today when I heard a popping sound from the corner of the wall. I rushed to see what had happened and carefully examined the scene. No smoke or anything, so that was good. I unplugged the charger from the wall and carefully examined the battery pack, worried that maybe it had exploded. But there's no sign of that, thank goodness! The battery pack wasn't that warm though, but the charger was very hot! Probably because I forgot not to leave it on the rug... :-X

Odd, because I wasn't sure what caused the popping sound. So I checked the fuse in the battery charger...no metal coil, so I'm assuming its blown. However, when I plug in the battery charger the battery is still charging. I disconnected the battery charger from the battery pack and tried plugging that in but the charging light only showed for a second before going out. It remains on when the charger to connected to the battery pack.

So is the fuse blown? If not, what caused the popping sound? It looks like everything still works, but I'm not plugging that thing in anymore until I can discern what caused the problem.

BTW, the charger was a 2.6V to 7.2 volt battery charger, set to 1.8 amp charging current (there was also a 0.9 amp charging current).

Any ideas?

Title: Re: Blown Fuse? Electronics still work?
Post by: Ro-Bot-X on August 28, 2009, 07:14:11 PM

It might have been the filtering capacitor inside the charger that blow up. A big electrolithic capacitor has passed away... It probably doesn't make any short so you can use the charger again, but that capacitor was there for a reason...
I would open up the charger, try to identify the value of the capacitor and replace it with a good one. Because it wasn't a short circuit, the fuse hasn't blown, besides, inside there isn't a coil but a thin wire that would melt if the current is higher than the fuse value (as it would be in a short circuit).

Title: Re: Blown Fuse? Electronics still work?
Post by: SeagullOne on August 29, 2009, 06:46:12 PM

Hmm...I see.

I wonder if I should just get a new charger then: the manual advises against opening the charger. They're not that expensive, and all I really have to do is make sure not to leave it on the rug anymore so it doesn't overheat.

Thanks.

Title: Re: Blown Fuse? Electronics still work?
Post by: Truckstop on August 30, 2009, 12:30:34 AM

check the charger with a volt meter without the battery connected, and check the fuse out of the charger with a continuity checker.

EDIT: sometimes chargers will appear to work when a battery is connected because voltage leaks back from the battery.