Problem Determination

A project log for Repairing a Delta-Q QuiQ Battery Charger

Sometimes when you throw money into a pit, you miss and hit the other side and actually save some.

leadacid44leadacid44 12/04/2016 at 22:300 Comments

Like I mentioned in the previous log entry, the charger, while nice, didn't work. It was kind of strange, it would behave like it was working. The lights would blink, it would take *some* current (as shown by a Kill-a-Watt) but wouldn't actually charge the batteries.

I took to using six independent 12v DC battery chargers while I was messing around with the charger. This let me keep going with the car for proof-of-concept testing. In fact, the car worked pretty darn good, so I was even more motivated to find out what was up with the charger.

So like any good hacker, I took to the internet with a flurry of searches. I kind of half expected to see something about fuses, bad capacitors, and so forth, but it seems that there is a fairly common problem with the Delta-Q charger current-sensing shunts being badly soldered.

Considering the time when it was designed and built (circa 2005-2010) I wasn't terribly surprised by this. This was the time frame of RoHS, lead-free solder, and bad Chinese electrolytic capacitors. A bad solder job on the charger would kind of make sense.

So like I said, I did some searching on the googles and found many references to 'repairs' that could be done on the charger. Apparently there was a current sensing shunt in it that had a known fault of a weak solder joint. If you whack the top of the controller, and the led lights changed their pattern, you had a likely candidate for repair. Okay, fair enough. Easy to test.

In this video you can see me hitting the charger. You can hear the relays clicking and the lights flashing, and it sitting on the right-most LED. That indicates that it is sending the least amount of energy to the battery. (in this case, none). I then initially tried hitting it with a socket wrench, but that didn't have enough blunt-force trauma, and I didn't really want to damage the heatsink. So I just punched it. and as you can see the LED lights change. Essentially the shock of the hit causes the shunt to work properly for a few moments, causing the LEDs to go up (to the left), indicating more current being sent to the battery pack.

Cool! Now I at least know what the problem is!

The rest of the forums indicate that these are the 'repair' steps:

Pretty much all of the instructions boiled down to these steps:

  1. Remove charger from vehicle,
  2. Remove 8 screws on top,
  3. Remove 3 bottom screws that secure the AC panel,
  4. Loosen the AC input panel and rotate 90 degrees to access the PC board,
  5. Locate the current shunt wire located where the PC board meets the LED board,
  6. There is a limited amount of solder on one end of the wire. Scrape the conformal coating until the wire is shiny and solder with 60/40 resin core,
  7. Reassemble by re-rotating the AC panel and install the bottom center screw until flush then complete the assembly.

Sounds easy enough, let's get started.