Question about NiMH AAA cells

I have a TerrLUX Lightstar 80 that had two Amazon Basics (white ones) AAA NiMH cells in it. It hadn't been use for a month or so, and when I picked it to use it - no light. I put two regular AAA cells in it and it worked OK, so that ruled out flashlight malfunction. I dropped the cells in my charger, and it showed one cell at 1.4, and the other a little lower, but both started charging. I just took them off the charger and dropped them back into the Lightstar 80 and it works fine. Anyone have any idea what might have been going on?

Most NiMh and NiCd cells have a high self discharge rage sometimes as high as 1-2% per day, so they discharge whether you use them or not. Also remember that one of the features of these cells is the voltage remains the same almost regardless of cell charge state, and NiCd or NiMh cell will still read essentially full voltage (about 1.25 volts) until it is nearly fully discharged. If you do the math, at 2% per day, they are going to be close to flat at 45 days. If you don't plan on using the light very often, use Eneloop® batteries, they have much lower self discharge rates, and can easily maintain most of their charge for almost a year. Very simply your batteries simply self discharged in the time the light wasn't used. This is a common problem.

Maybe you had one of the batteries turned backward if you knew you were going to store it. Eneloops are not depleted at 1.4 volts.

I just got out some "candle" LED lights for Christmas. They used two Eneloop batteries and I noticed that the switch for the candles was turned on. These candles have a timer so they run 5 hours and go off for 19. One Eneloop had 0 volts and the other about 0.75V So image by leaving this candle on, the stronger cell was discharging the weaker cell, until they both discharged. I recharged both, and they returned to almost full capacity. Luckily this full discharge is OK for MiMh batteries, but NOT good for LiIon batteries.

Maybe the light was locked out or something was not making good contact??