I believe your mAh capacity numbers should be 1,5XXmAh…not 1.5XXmAh…for if it really was as stated, there would be no life out of these. At least that is what I think.
Great post, thanks for taking the time to test and share!
I got some of the similar Hixon AAA cells from Liion Wholesale and so far they’ve been pretty good. I haven’t really done any testing/observation with them, just anectodal notes in use. I thought it was interesting that when they cut out, they read 0v on the meter but after about ten seconds on the charger they show 1.5v again. That low voltage feature on the Xtar sounds like a smart idea for a lot of devices, probably would make it worth choosing those over other brands. One of these days I’ll unwrap one for a look at the boards and cell.
Blockquote Macgravy
“I believe your mAh capacity numbers should be 1,5XXmAh…not 1.5XXmAh…for if it really was as stated, there would be no life out of these. At least that is what I think.”
Hmmm… right you are! In my post-midnight mind I thought it clever & expeditious to do a ‘copy’, then ‘paste… paste…paste…’ through that repetitive section. Didn’t notice I’d copied a “.” instead of a “,”. Thanks for the catch. Corrected.
slmjim
Can you charge TENAVOLTS batteries in Xtar charger or the other way around?
I’ve not tried.
slmjim
Would you be able to measure charging voltage?
From what I read on XTAR website it’s constant. If TENAVOLTS also uses constant voltage and the voltages are similar, mixing batteries and chargers should work…
Fairly confident they are both just 5v USB ‘pass through’. I know the Tenavolt is.
The issue would be contact for + and - poles.
If this is the case than a modified USB cable should be able to charge them…hm…I’m thinking whether adding a switch to one of my chargers is a good idea. 
Some of them are direct USB charge; AA and AAA.
This is a snip from this BLF review of Tenavolt: TENAVOLTS AA Lithium 1.5V rechargeable cells
[The output on the terminals of the supplied charger appears to be 5.25V without the cell present.
Actually, it’s basically passthrough voltage from whatever USB power source you’re giving it. Looks like it’s feeding 5V to the buck regulator, which then charges the internal Li-Ion cell.]
Some people seem to think you can charge them in a regular charger. I’ve tried numerous chargers on a few cells. Some you don’t have any success at all. A few of the USB charge type will seem to charge on a regular charger. Trouble is, with all the electronics ‘in the way’ it’s difficult to figure out if it’s actually working properly without putting them in the proprietary charger and see if more current gets added.
I have a few applications they are useful for. Mostly it’s just an interesting endeavor to mess around with them. Unless you get them at a good price, or you have an application that can actually put the voltage to good use, they re not a deal at all. I find the AAA kind of pathetic. There simply isn’t enough room in the tiny can for the electronics and the essential battery chemistry elements.
I have 2 items that don’t run on NiMH and run through AAA alkalines like crazy. I stocked up, so I have some time to decide but I think that 1.5V Li-Ion cells are the right thing for me.
Capacity is pathetic? With XTAR 1200 mWh it’s about the same as the best NiMH out there
I also looked at cells with USB slots but they have lower capacity (especially AAA with Type C) but I feel it’s just faster to put a cell in a charger than to stick a cable into it. And the only quality brand that offers them (Keeppower) doesn’t seem to think Type C is worthwhile.
I’m not happy that there are no chargers that support these 1.5V cells together with regular 3.7 V ones. This is the biggest reason I hadn’t pulled the trigger yet.
Specifically, AAA is pathetic. Of the 3 brands I’ve tested, they barely break 300mAh @ 0.2A draw.
AA can be poor > decent depending on brand.
Having both micro and C USB charge, along with proprietary charger (AA only), so far I like the proprietary chargers.
The USB generally seem to not fit in a nice smooth manner.
Could you please list the brands that you tested?
ADDED:
Here I see a test where XTAR got ~1100 mWh at 0.6A.
All charged with stock USB charger until blinking light went out.
All discharged with ZB206+ dedicated discharger, set to 1.0v low cutoff.
For these cells I standardized on 0.2A current, but I did push them at higher rates to see what they would do. Most started showing distress at 0.5A and none would go more than 0.7A.
Deleepow AAA 1.5v Lithium x4 |1200 claim| Measured - 317 – 370mAh/0.2A
S Energy 7 AAA 1.5v lithium x8| 490mAh/.735Wh claimed | Measured - 350-370mAh/0.2A
HuaHui Energy AAA 1.5v Lithium x4| 600mWh claimed | Measured - 300-350mAh/0.2A|
Thank you for the details they are really helpful.
I tend to stay with good brand cells because then I know that my expectation will be met. But in this case I actually considered off-brand cells because I found no good brand that would offer 1.5V AAA cells with Type C.
I agree that this is low…and for me it’s probably too low as well.
I have not tested a better known ‘brand name’, since none of the big name battery makers seem to actually make any of these, and I’m cheap. 
I understand wanting to use USB-C to charge, but I think on this tiny form factor you might be giving up a fair amount of potential capacity. I think a buddy got some Tenavolt AAA, which are decent in the AA form. Maybe I can get one to test out. Could be interesting, but that would only be a ‘one off’ and not necessarily translate to other brands of the similar construction.
I got a couple of 1+ year old Tenavolt AAA from a buddy. As before : All discharged with ZB206+ dedicated discharger, This time I let the [auto] function go to 1.2v low cutoff. So, absolute capacity might have been a tad higher.
These claim to be 1110mWh
Both cells tracked almost identically.
590mAh/0.2A , 570mAh/0.5A, 560mAh/0.7A, 515mAh/1.0A 1.0A seemed to be a functional upper limit. I did not push beyond that level.
This is almost 2x both the capacity and amp support of the other ‘cheap’ AAA I tried out. I consider this to be quite good.
OTOH, they are very expensive unless you get them on a good sale: $31 for 4, $35 for 4 + charger on Amazon. I’ve seen them as low as $12 x4 for batteries only, but that was a LONG time ago.
1 Thank
I ran some tests on the newest iteration of the Xtar AA 1.5 volt cells.
post #46 and on. Thought it may be of some value to this thread.
My conclusion: Unless you have some device that is very sensitive to voltage, I struggle to see the value of this kind of cell. They are expensive! The capacity is not remarkable (VS NiMh). They take a dedicated charger (which is pretty slow) . They have a relatively high self discharge rate. So other than something that just can’t work with NiMh, why use them?
If I am missing something, I would really like to read what that is. Please comment.
NiMH cells do not work well in every device.
Alkaleaks may work only for a short duration in these devices.
Alkaleaks are not rechargeable.
Lithium primaries are expensive and also not rechargeable.
NiMH and Alkaleaks perform even worse in cold weather.
There are clear use cases for these cells. You’ll know if you need them. Some devices get terrible battery life on alkaleaks or NiMH. 1.5V rechargeable liion cells will solve the problem and are a much better value than Lithium primaries which are not rechargeable.
1 Thank
Thanks. In my use case, after considering everything that you mention, I still fin limited application for this kind of cell.
I am sure that there are situations that they fit well just none that I personally see.
Value is relative. Time and aggravation come into the picture, for me anyway. But , yeah, that is a personal problem… 
And yes, for voltage sensitive devices, these could be the best option. (If one has any of that kind of device). What if that is not a consideration?
True, but not as expensive as these, and no dedicated charger required. I wonder how many cycles these are really good for.
With the relatively high self discharge, you also need to top them off regularly. The Lithium AAs have a 10 year shelf life!
I had thought to use them in remote sensors for my weather station. They are older units and shut down quickly on NiMh cells. I am pretty sure it is a voltage problem rather than capacity. SO they should be a good fit. The problem is that longevity is of primary concern for these. Some are a PIA to get to. Replacing the cells means removing five tiny screws that love to get lost and positioning a waterproof gasket just right. The main unit takes 4 AAs. Yes I have been using the Energizer Lithium cells. Yes they are expensive, But they give me 10 to 12 months of use. I got a set of these Xtar cells with the hope of replacing those, but after testing I am certain they will not give me the time in service that I need/want. Too low a capacity and too high self discharge. They would work OK if the time in service was not an issue. Though having two sets to insure continuity would be like ~$50. I can buy a bunch of Energizer Lithiums for that. (Yeah, I get it, throw away, not good!)
So I was wondering if anyone had any specifics for something that they would find them suitable for. As long as I have them, I would like to figure out a good use for them. For everything other than the sensors that I use AAs in NiMh are just fine.
I have a motorized house door lock that doesn’t work properly on NiMH and in the winter time it doesn’t work very well on alkaleaks either. These 1.5V liion batteries are a good solution for that device.
Rechargeable 1.5V liion cells can be used in devices and situations where disposable lithium primary cells (1.5V) are more or less required.