During the recent season, vex batteries were giving us quite a bit of problems.
Charging them with the provided charger would cause the LED to start blinking after 4 mins or so (which means charging stopped after 4 mins). Obviously the battery was still flat, so we had to repeatedly unplug and replug the battery every 4 minutes to have it charged to full charge, or until it can charge the battery itself without user intervention till it is fully charged.
We have like 3 chargers and 6 batteries which have this issue.
Any opinions regarding this issue? Is it a charger or battery problem?
Basically its: plug in battery, and approx 4 minutes later the LED starts blinking. Occasionally, the LED dosen’t and it continues to charge.
I read from the other thread that the battery actually needs to be seated in the slot, as depressing the springy piece of plastic actually determines that its supposed to charge a 7.2 or 8.4v. Is that true?
You are correct. If the 7.2V Battery is not seated completely in the charging cradle – pressing down the plastic tabs at the back of the Vex Charger, it will not be charged correctly and can be permanently damaged. If the Vex Charger does not sense the 7.2V Battery from the plastic tabs, it assumes that a 9.6V Battery is connected and it charges the Battery connected at the 9.6V rate. Thus, if you just lay the 7.2V Battery beside the Vex Charger and connect it, it will be overcharged at the 9.6V rate which can permanently damage it. You will also get the Red Flashing LED on the Vex Charger to indicate that it has detected a problem.