Need help with rechargeable AA Lithium

Wurkkos

andrewnewman

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Greetings. I believe you are referring to the relatively new crop of AAA and AA format batteries that contain a LiIon cell and a step down circuit to present 1.5V. These usually have a built in charging port and low voltage cutoff. Sadly the few I have tried have been relatively disappointing. I have run into a couple of problems. Quality control seems to be lacking. Frequently 1 or 2 out of a pack of 4 will either fail to take a charge or go flat shortly after coming off the charger. The other problem is that while LiIon generally doesn't have a self-discharge issue, these cells seem to lose their charge on the shelf quite quickly (1-2 weeks). Perhaps others have had better luck or perhaps there is a brand I haven't tried but I can't honestly recommend these for security cameras. If the cameras won't handle traditional NiMH chemistry due to the lower (~1.2V) voltage, I'd stick with the expensive non-rechargeable Lithium primary cells.
 

hb88

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Very curious on this as well. The reviews on all the offerings from Amazon seem to be a hit or miss. While even the models which have 5 star reviews have a good number of 1 & 2 star reviews makes you wonder of the quality control of the cells.

Would be really nice if a reputable company like Eneloop/Duracell/Energizer got into this game but is suspect the risk is too high with the Li volatility and not worth the liability headache. Hate going through non rechargeable batteries on the devices which don't run on 1.2v NiMH eneloop and similar due to lower nominal voltage.


Also another factor to keep in mind and somewhat deceptive advertising by some sellers on Amazon and just consumer ignorance is the difference between mAh and mWh. Most consumers overlook or correlate them as the same when they actually are not.

Amp hours (mAh) X voltage = mWh
volts = Amps x Resistance
Watts = Amps x Amps x resistance
m = milli, a prefix to indicate the small amount (without the m (2800mA = 2.8A))

The conversion from Lithium-ion ~3.7 volts to 1.5 volts: 750mAh X 3.7v=2775mWh (round up to 2800mWh, advertised by some Amazon sellers), but power is 1.5v X amps through down converter. So 2800mWh/750mAh=~3.7v

This is a prime example of consumers thinking they are getting a 2800mAh battery when it is in fact a 2800mWh battery and the true capacity is 750mAh at the nominal 3.7 voltage of the battery. There is expected loss at the down converter but for the sake of math lets look at this conversion: 2800mWh/1.5v = 1867mAh @ 1.5v when comparing to a Eneloop NiMH for example rated at 2550mAh @ 1.2v


Back to the OP, hoping to see more data on this as these kind of batteries become more mainstream and hopefully reliable. Will follow this thread for sure.
 

degarb

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I need recommendations for a high quality rechargeable 1.5v AA Lithium for security cameras.
Yep. I just invested a few hundred into trail cameras that need 8 AA at 1.5 volts, not 1.2 volts. I did find 2x18650 cameras from china, ordered 3, but time will tell.

I got 16 rechargeable lithiums from epoch, 2300 mah. They are a little fatter and barely fit into the battery case of the cell trail cameras from spypoint. What I noticed is that rather than using 12v of the batteries, they break it into at least 2 sections, maybe 3. So, they could be using 6 volts. What I noticed was that if I take one cell out, the camera still works. So, since on my first test, it is questionable that I got all 8 cells to fit properly in (maybe one cell didn't make contact, due to the extreme close fit, my first run on the re-li-aa's might be half of true capacity.

So, on the primary heavy duty aa's , I dropped 25 percent in one 7 day week, on my first 2 cell trail cameras. I assume the percent is calibrated for primary AA. On the rechargeble lithiums, it always said 100 percent, but both cameras stopped working at day 9. Now, I am not sure if this means I could get 18 days if I could seat all cells properly. So, when I recharged the cells, I didn't notice more than 2 cells that charged quicker than the 3.5 hours it took to charge all 16 cells. But, just in case, I only put 7 lithium cells in each camera and put one primary, which allowed all the cells to fit for sure and make contact. Next time I will volt test. I didn't bother volt testing the cells, because I expect these cells to trip when low, and so, I probably will see 0v or 1.5 v and nothing in between.

My other problems is that I intend to move these cameras around frequently, which means the cells might jiggle out of place. I might be able to buy an open cell foam to push between the door and the cells, to prevent jiggling and hopefully not stress the door latch.


I bought several aaa rechargeable lithiums for several closeout energizer headlamps. What I quickly learned is that they have a thermal shutoff protection and shut off if the light gets a little hot, which is any setting above the lowest. So, I had to go back to the nimh. I might be able to use these in low drain devices.

These cells are quite the investment. Someone needs to test various brands, with new benchmarks that are more appropriate for this new type of cell. Heck, they may only be useful in low drain, cool devices. Or maybe some brands will work fine.

NiMH have their quality control issues too. I am not a fan of nimh, and have been so happy to convert to 18650. There are so many issues with the best nimh, especially if you need 16-32 a day. I was hoping to avoid the crummy downsides of nimh with rechargeable aa lithiums, as I have with 18650's. I am just holding my breath that some brand cracks all the specification and quality issues with these bucked 1.5v rechargeable li aa.
 

fivemega

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Instead of using 8 AA at 1.5 volts, total 12 volts, you may go 3x18650 if fit.
Much easier to charge and last longer.
 

lumen aeternum

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Yep. I just invested a few hundred into trail cameras that need 8 AA at 1.5 volts, not 1.2 volts. I did find 2x18650 cameras from china, ordered 3, but time will tell.
Have you thought about creating external battery packs & using a weatherproof plug? Maybe even a 12v UPS type battery with a voltage converter. Interested in the quality of the 18650 cameras.
 

vicv

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Also we need to stop thinking about NIMH as 1.2v and alkaline as 1.5v. They're both nominally 1.2v. Look at HJKs site and compare an alkaline AA against a nimh AA and look at the discharge curves. You'll see the nimh will have higher voltage than the alkaline after a short period. If nimh won't work in a device, then with alkaline it'd stop working when the batteries still had 75% capacity left
 

Lynx_Arc

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Also we need to stop thinking about NIMH as 1.2v and alkaline as 1.5v. They're both nominally 1.2v. Look at HJKs site and compare an alkaline AA against a nimh AA and look at the discharge curves. You'll see the nimh will have higher voltage than the alkaline after a short period. If nimh won't work in a device, then with alkaline it'd stop working when the batteries still had 75% capacity left
Not totally accurate as it depends on the current draw from the battery itself. Alkaleaks start at about 1.5v under light loads can keep that voltage and at 1.3v they are over half depleted with light loads. Nimh start at 1.4v or so off the charger and drop to around 1.35 or so after a day or two and slowly drop to 1.1v where they are essentially depleted for all practical purposes. The problem is that many devices are light loads and stop working well at about 1.3 v or a little less where alkaleaks are mostly used up and where nimh are just started to be used up.
 

vicv

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Yes but we're talking about lights here generally. They are not low drain devices. In this case cameras. Which I also imagine draw quite a bit.
Even at 200ma nimh have higher voltage for most of the runtime.

Courtesy of HJK.

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