Battery Charger Repair

[VardyR]

The first time I charged the battery using the frame mount connector it wouldn't charge. I found the charger had stopped working, it had worked previously when I charged the battery out of the bike. I found the connector on the bike had the connections reversed so it obviously had damaged the charger. Would anyone know where I should start looking to repair the charger ? Unfortunately there were no inbuilt fuses to protect the charger.
There is also no chance of a warranty claim.

 

[bram.biesiekierski]

Unless you can pull it apart and see a blown component etc, and have the skills to identify and replace it. Its probaly not worth it. You could probably buy a new charger of the needed voltage for less than the price of getting it professionally repaired.

 

[Alexbn921]

If you have to ask it's above your skill level

 

[VardyR]

The investigative work is well above my skill level but replacing a component isn’t. If a tech person who had knowledge of this kind of fault identified a capacitor or resister etc that could have failed then I could test that and replace it.

I never give up without a fight

 

[RustyIron]

If a tech person who had knowledge of this kind of fault identified a capacitor or resister etc that could have failed then I could test that and replace it.

Replace the 6.8 pF capacitor.

 

[VardyR]

Cheers
If I can find it I’ll replace it

 

[VardyR]

Replace the 6.8 pF capacitor.

Hi
I see a couple of capacitors on the output. The 10A is directly on the output but no other markings. Would this be the one to replace ?
Thanks

 

[RustyIron]

Hey, @VardyR.
You went through the trouble to take a picture, so I'll take some time to type out my thoughts.

First, you didn't state the manufacturer or model of the motor, battery, or charger. The question is in the "Do It Yourself" forum, so I have no idea how to help. Nobody does. Since we don't know what you're working on, there's no way anyone is going to diagnose the problem.

Second, you noted that the polarity of the plug on the frame was reversed, and then concluded that the charger was bad. Perhaps you're right, but I wouldn't bet my life on it. There's no reason to think that the battery might not be bad.

But since you asked, I've repaired many boards over the years, boards and systems I had never before seen. But I've also thrown many boards in the trash... or across the room like frisbees... so keep that in mind.

The first thing I do when faced with a mysterious problem on a mysterious board is to look at EVERYTHING. The first thing I noticed when looking at your picture is the TERRIBLE solder on OUT+. I don't want to rile the moderator by making disparaging comments about the workers who assembled that charger, but suffice it to say, they're not the same guys building Mars Rovers. The big power diode also looks to have dodgy soldering, but I can't tell from the fuzzy image. When they can't even do big solder joints well, I have zero confidence that they can do the delicate work. There's nothing you should do about this, other than realizing you're not working with high-quality electronics. The other thing I noticed was the darkening near the bottom of the 470 microfarad cap. I would look more closely at that area.

If grasping at straws, I might test some components in areas of the circuit that I recognized. It takes some experience, and isn't necessarily conclusive, but can point you in the right direction.

The last step is to hook up the board so it's running in the system, and then check voltages on components. Again, it take some experience to recognize areas of a circuit, and to recognize readings that are odd. Also, it's not at all safe to hook up all the circuits with all the wires and components exposed. Not only is it unsafe for you, it's unsafe for the parts. One false move, and you'll blow stuff up. It's easy to find videos on Youtube where people futz around with lithium batteries and achieve undesirable results.

 

[bram.biesiekierski]

There does look like a burn stain on the base of the cap. But could just be a shadow.

 

[VardyR]

Brilliant thanks for that
I will do as you say and run it up and see what readings I get.
Much appreciated your help.

 

[nicobie]

Questions like this seem to be out of the scope of this forum. I'd try EBike Troubleshooting