Energizer Lithium Ultimate AA probem

I've had a few occurrences where one cell will be completely dead and the others are still at full capacity. For example the dead cell will be about 0.7 volts and the others in the same set are still at 1.6 volts. The cells can come from the same new package and installed into the device at the same time yet mysteriously it will go dead after a few months. I replace the batteries with all brand new ones at the same time. The devices are stored indoors climate controlled to 77 degrees constantly.

I've noticed this in my Fenix HL30 which takes two cells, the light output will dim significantly. I can have the batteries installed for a few months with an occasional 5 minute use a couple of times a month. Seems to be working fine then then the next time I turn it on I have no brightness control and the output is dim. When I check the battery voltages one is good and the other is bad.

Same thing happens in my minimag LED.

I have a garage parking sensor to tell me when to stop so I can clear the garage door and after a few months it will just stop working. check the batteries and the same thing, one cell is dead and the other 3 are still over 1.6 volts.

seems strange that in multiple devices one battery is draining so much faster then the others in the same set.

I had this problem in low/parasitic drain devices. Unless I had to use lithium cause of temperature issues, I swapped back to alkaleaks or enloops.

hmm....that makes sense. the parking sensor is a constant low draw and the Fenix has an electronic switch. I use the lithium because I have lost way too many things to leaking alkaline AA cells.

DHCrocks said:

..........seems strange that in multiple devices one battery is draining so much faster then the others in the same set.

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Interesting. You know I've never done a run time test with multiple cell lithium batteries (L91s). And all the tests I've done with single AA flashlights, I've gotten what I think is expected out of them. I haven't ever done a run time test with low draw though. I might learn something here.

Could it be that once those batteries die, they die quickly and what you might be seeing is just the first one that goes? I know all my Eneloops in multi-cell flashlights pretty much go down evenly.

I guess if you could verify that you're getting decent run time and usage by the time the first cell depletes, that it doesn't matter that the rest haven't got to that point yet. However 1.60v still sounds like a lot of capacity in them. Mine new register around 1.80v.

Yes, they die fairly rapidly at end of life, the curve is more of a straight drop then a curve. Lol

"Could it be that once those batteries die, they die quickly and what you might be seeing is just the first one that goes?"

+2

DHCrocks -- are you testing voltage under load, or just using a multimeter? It's very possible that the other batteries are also nearly empty.

I've found Lithium AAs are nearly depleted when they reach 1.6v so a drop from 1.6 to 0.7v probably isn't as much in capacity difference as you think it is. It is possible some devices that have lower current drain on alkalines have even lower drain on nimh and that would probably make for higher drain on lithiums due to the current drain is directly proportional to the voltage and lithium AAs have perhap 15-20% higher voltage which could translate to them being drained that much faster.

I'm just testing them on a multimeter for the voltages. I also put them on a old radio shack battery tester and the dead cell doesn't even move the needle and the good ones go all the way to the green full side of the scale.

when I pull the batteries out I use the ones that still have 1.6v or so on them into a single AA flashlight (thrunite T10S) and get a lot of run time out of it, so they seem to have quite a bit a capacity left.

for the parking sensor (4-AAs), I could swear I was getting about 2 years from a set of alkalines but the lithium seems to only last 12 months or so.

in my exp, i've found lithium primaries do not preform as well as alks in low drain situations, i have several places where i wont use lithiums (indoor/outdoor thermometers, bedside clock, doorbell, etc.). they drain lithiums in about 1/2 the time as alks. then, in my wiimotes i use eneloops but those have horrid parasitic drain so rechargeables is all i'll use in them.