VEX Battery Charger Electronics Question

My team accidentally broke one of the safe/fast switches on the 7.2V battery chargers, and the other is not yet broken but is loose. Upon opening the former’s case, I have discovered that the plastic switch itself had broken from the metal stable that connected the switch.

With this switch gone, is the charger’s default charge method now ‘safe’ or ‘fast’?

And I am correct in assuming the creation of a new switch/soldering the two connectors together will cause the mode to switch the other way?


I would make more sense with a photo of the problem. It should stay set where ever you push it into unless there is no metal that can make contact then it shouldn’t work at all.

There are 2 wires. When the wires are not connected, the charger is in safe mode. When connected, the charger is in fast.

Thanks tutman96, though we did just talk.

devinc, the switch was pushed into the charger and all the components came loose inside the charger.

I really do not know without looking at it or a wiring diagram. As long as you only use the large 7.2V batteries you will be fine wether it is fast or normal. You just can’t charge the small square ones into it on fast.

doesnt it like birst in to flames

In most electronics, it’s standard to have a jumper to switch into one of two modes; in this case, “no jumper (open circuit)” turns the charger to a lower current charge mode
The jumper itself is not part of the charging circuit but part of a signal circuit that returns “true” or “false”

Most likely
Depending on the current, it may range from instantaneous flames or explosions
gradual smoke coming out of some cells (with the excessive heating of the plastic wrapper) followed by visible flames

Low-Current charging is definitely the way to go