Help!
Sailor sent me this email, and I sent the following reply...am I correct? I don't know batteries very well, is my advice correct?
sitting in cockpit tonight; writing on laptop with zebra on my head and at second level so I can see the keyboard, which on my laptop is unlit, and compare to notes from handwritten journal. quite pleasant to do this in cockpit with warm light of zebra on level two.
after about an hour the zebra goes out and will not relight.
i remove eneloop and reinsert (i.e. i reboot). it will not light.
i go below and remove kodak rechargeable from incandescent flashlight and insert into zebra, which then lights up.
i insert a different, unused eneloop and the zebra lights up.
i then tested a number of batteries for charge levels with my digital marine voltmeter with following results:
-original eneloop (about one hour of usage in zebra at various light levels, but mostly level two): 1.154v
-partually used kodak: 1.274v
-fresh, unused eneloop (dark blue casing): 1.334v
I then got a bit happy and tested a selection of my new, unused AA eneloops. Just got them in the mail (via amazon but in --- suitcase) three days ago in several packages. I list below voltages by battery casing color in order tested, all AA:
white--1.310v
white--1.308v
white--1.309v
light blue--1.333v
dark blue--1.335v
light blue--1.334v
white--1.309v
dark blue--1.115v (this batt was tried for first time two days ago and would not light the zebra--a bad batt, i assume--blue casing is a bit crinkled; paint can be scraped off with fingernail--innards going off?)
Clearly the batteries with colored casings carry a stronger charge. Intentional? Important?
Disappointed in staying power of "precharged" eneloops, though it's early to tell. Am I missing something?
What are charge levels of small batts? I know how to read deep cell batts, but is 1.15v in a AA empty? is 1.334 strongly full?
Being in La Paz where packages to and from the US often take months if they arrive at all, I'm not in a position to return for exchange or complain to anyone but you.
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also, i notice that the switch actions for the two zebras are not uniform. where as i can operate one of the zebras between the three light levels with ease, the other switch is "sticky", will not light or change levels with the same kind of touch sensitivity as the other...takes me some time to realize it's not broken, just different.
My reply:
Ahoy there! Sounds like a battery issue indeed. Some initial thoughts:
"Precharged" means the cells were charged before leaving the factory, but doesn't account for time sitting in a warehouse or store. What's unique about the Eneloop is that it has a slower self-discharge rate than the usual fast-self-discharge-rate NiMH cells. (For example, the batts that power my Makita drill....pretty much gotta charge the battery BEFORE work, as charging it a week before you need it and the battery will be depleted.) The new LSD (low self discharge) batteries are a good, but not perfect, improvement on this problem. I would not take the "precharge" branding too seriously as you don't know how long it's been sitting in a warehouse. I would deplete the first charge, as you are doing, expecting it to be short, then recharge.
An AA is normally 1.5v in full charge state (I read somewhere Eneloops are 1.45v fully charged, and they rapidly fall to 1.4v?). So it looks like yours were sitting in a warehouse for awhile to fall to 1.3 (also read somewhere that Sanyo sends them less than full charge, around 1.3 so maybe that's normal). Don't quote me on this, I'll check, but I think you may not get full capacity until you do a couple of deplete-recharge cycles. So fresh off the charger for the first couple of times may not get you 1.5 or 1.45v...again, I'll check with the forum.
Regarding the different colors: from memory, but here goes. There are two version of eneloops, old and new. Old version is white, has letters MODEL HR-3UTG. New version is white or many other different colors, usually blue. What distinguishes "new" Eneloops is a CROWN symbol, and letters MODEL HR-3UTGA, and the ability to be recharged 50% more (from 1000x to 1500x). I bet all yours are crowned models, which means all the new eneloop version regardless of color. (Color was a marketing variation.)
Measuring voltage is an imperfect measure of what the battery's doing, because it's not under load as you do this. That's why I tried to 'sell' you a battery tester in one of my previous emails, which tests under load. However, you VOM will give you some indication of what's going on, some indication of depletion.
Regarding the "bad" blue Eneloop, don't toss it till you give it a recharge or two. Remember to recharge according to the instructions that came with the Eneloops. I think they want to be recharged in pairs.
At this point I suspect your problems will go away with a couple of discharge/recharge cycles, but I'll put a call into the CPF forum and get the input of people much more educated about cells than I am.
Regarding the difference between your two Zebras, mine are different also. Mine have somewhat different tints.