Aldi Lithium Battery charger

Thread Starter

debe

Joined Sep 21, 2010
1,389
This charger failed after a few charges & i decided it was not worth a 300Km trip to get money back on the warranty ( there was probably no chargers in stock any way) Opened it up & found one of a pair of 200V 5A shottkey diodes, one was shorted (they are in parallel) So having some 200V 8A shottkey diodes lying around i replace both of them, & it now works fine. So some times you can have a winner.1.JPG2.JPG3.JPG
 

Ya’akov

Joined Jan 27, 2019
9,071
There seems some irony that electronic items more likely to fail are also, frequently, easier to repair than those with more reliable and sophisticated designs.

I have a Bosch charger that sits disassembled waiting for me to bother going past the quick assessment I first gave it. I would probably be more motivated if not for the fact that I have, literally, 10 working ones, three of which sit on the shelf in reserve.

Very nice to hear of a repair success. I find repair one of the most satisfying technical activities because it feels like rescuing value.
 

Thread Starter

debe

Joined Sep 21, 2010
1,389
Theres a MOSFET on the heat sink for the switch mode supply. Other side of board has surface mount components & driver chip. If they were faulty i probably would have not bothered to repair it. What i find interesting is even with a short on the power supply, it just shut down with the overload & not destroy its self.
 

wayneh

Joined Sep 9, 2010
17,496
I was all set to jump in and say, "it's a capacitor", but I guess these things have other failure modes.

I've taken apart maybe a half-dozen or more SMPS bricks from various appliances and they have ALL failed due to a high voltage capacitor failure.

The old-fashioned wall-warts that they replaced occasionally failed if they had rectifying diodes, but almost never because of the transformer. The SMPS was introduced to replace the "more wasteful" wall-wart but I wonder, with the wisdom of hindsight, if that was the right decision. I believe building all those replacement SMPSs and sending all the dead ones to the dump is probably worse for the environment than the tiny vampire current of long-lasting wall warts. Anybody ever see data on this?
 

Thread Starter

debe

Joined Sep 21, 2010
1,389
The IC 1 is QBUA, thats all thats on the chip, i suspect its a custom made drive chip & its small. The CM4N60 power MOSFET is 600V 4A. IC3 is 78L05 reg. IC4 is LM358 dual op amp.IC5 has no markings but does drive the 2 indicator LEDS. If any of these parts had failed i would have binned it. 5.JPG6.JPG7.JPG
 
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