AAA battery charger, rapid blinking LED

We are at the worlds and one of the LEDs on our AAA Battery charger just starts blinking rapidly.
Re-inserting the battery fixes the problem, but it comes back after a while.

I think that means it is fully charged

No, fully charged is when the light turns off

The rapid blinking for the AAA batteries mean that there is a problem with that battery.
Sometimes that battery fixes itself, but most of the time it won’t.
(Don’t trust a rapid-blinking AAA battery for your remote at competition, or ALL of the lights on the remote will turn red.)