kenArchi Loc: Seal Beach, CA

I notice that one of the four batteries in use lose it's charge more while the other 3 are still reading full/good charge.
This battery becomes hard to charge.
And of course these AA batteries are more than 10 years old.
That's probably why they are wearing out.
Also they are used every day in motion lights in the garage as well as in multiple flashes.

Longshadow Loc: Audubon, PA, United States

If the manufacturer has good quality control I would imagine that they would, but they won't die precicely on the same day. Could be weeks apart.
Are they all from the same date of manufacture (lot code)?

TriX Loc: Raleigh, NC

How about 4 new Eneloops? Certainly one can go bad while the others are still good or marginal, but if they are 10+ years, I’d replace them all.

kenArchi Loc: Seal Beach, CA

The charger manual says when the red light blinks the battery is no good any more.
Ok got it. Read the manual.

I have rayovacs. Old ones are 1800mah,
And some 2300mah
And new rayovacs I bought yesterday are 2500mah. Same as eneloops. Made by rayovac.

TriX Loc: Raleigh, NC

Well if the red light is blinking for that cell, then you have your answer. But if it’s not blinking that does not necessarily it will hold a charge for as long as the others - the light just indicates it was able to charge it to the rated voltage.

kenArchi Loc: Seal Beach, CA

Ok, reread radio shake manual.
Blinking red means actual bad batteries.
Same with rayovac charger will not charge.
Well, the batteries are old.
Good batteries will equaly discharge.
I just now remember an electronics engineer was telling that the batteries will keep each other charged unless there is a bad one in the group.

So, I will use the 4 new good ones in device until they are expended and take a reading on each one.

I replaced only the one bad battery and the light system continues to work good.

Therefore it seems, I did not need to recharge all the batteries all the time.
Which may degrade their life spand.