When I try to charge my BA1400 battery, the charger lights start to slow blink green like it is all going well, and then after a while, the charger stops and the battery blinks green fairly rapidly. Once I pull it out of the charger, the light stops. Pressing the button on the battery does nothing. Putting it back in the charger starts that same cycle again. It appears to have no power at all as it won't run anything.

The charger still works fine with my second, larger battery.

Clearly, something is wrong with the battery, but there are no orange or red lights. It was working well the one or two times I used it this spring (i.e. not obviously diminished). I stored it inside for the winter, and use/charge it maybe (maybe!) 10 times a year. The manufacture date is 2017, so no definitely no more than 50-60 charge cycles.

What does a rapid blinking, green battery light (while in the charger) mean? Is there a way to "reset" the battery so it will charge again?

Thanks.