It has come to my team and my attention that on some of our smart chargers, the toggle switch for “fast” and “safe” are broken. I was wondering if anyone else has had any issues with these breaking, and if it has caused and damage to batteries. I do not see how the switch could cause any damage due to the fact that it is probably stuck in one position now but my team did find that we possibly overcharged a few batteries, which generated a large amount of heat. Any comments are greatly appreciated.
My students found one smart charger whose switch was also broken. No one knows how it broke. 
It appears to be stuck in “safe charge” mode which is the mode we use most often. Seems to work but we aren’t positive.
We always use SAFE mode when charging, as per the instructions, but our battery packs still get pretty hot if we leave them on the charger overnight. In one instance, it was hot enough to melt the plastic casing.
We are currently using the “new-style” batteries - short and squat, not long and skinny.
We have five that have broken, they have been glued to the low speed charge side.
hey jay maybe thats why our batteries were getting so hot at our competition
I solved this problem with some simple electronics skills. As far as I know, this does not affect competition illegality.
The problem is that the switch is made poorly, it falls apart if you put pressure on it. How the charger’s safe mode/fast mode works is that there are two wires. If the two wires ARE NOT connected, the charger is in Safe Mode. If the two wires ARE connected (in this case with the switch), the charger is in fast mode. So, when the switch does fall apart, the switch no longer connects the wires, thus it is in Safe Mode. This is what happens majority of the time, but not always.
Anyways here’s some instructions:
You need a #1 Phillips Screwdriver, and if you want, a SPST/SPDT switch (you can get at Radioshack/The Source)
- Peel-off the rubber feet on the side where you can plug in a power cord (not the side with the battery cable). Remove the two screws with a screwdriver.
- Peel off the small decal on the opposite side of the rubber feet, where the light indicates charging/charged. Remove the two screws with a screwdriver. Carefully pull apart the two halves.
- Locate the side with the switch, and attached to the switch should be soldered on two wires with a connecting end to the logic board (PCB board).
- Either pull it off, so that the charger is forever in Safe Mode, or de-solder the switch and replace with another one.
- Put the charger back together.
Sorry, but I don’t know/don’t have the time to upload pictures.