Battery changing polarity?

[rud0g]

Hey everybody,

I have a nice little Blue Toyota Bb clone with yellow flames, and 2 batteries in the chassis.

I regularly get 30 minute run times.

However yesterday after charging, (I use a 4xAA pack for 2.5minutes to charge) I could only run about five minutes.

I charged again and got the same result, so then I pulled everything apart and started poking around with my meter.

The second battery flipped polarity!

(And YES I do know which ends are normally positive + negatvie)

It will not take a charge any more, even accounting for the flipped polarity, it only reads about .95 volts and 0 milliampsDC.

I have plenty of batteries, but it takes a long time to match batteries for voltage/current/drain/charge characteristics and I don't really feel like doing that again.

Anyone know if the Battery is repairable?