【New Product】XTAR 1.5V AA 4150mWh Battery

If you can, please tag me; really interested in seeing an in-depth review of these.

It is possible to have 1200 cycles or even more from ordinary li ion cell, but you need to charge it to 80% and discharge to no less than 40%. (iirc this is how all ev work), but then you cut rated capacity in half.

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Thanks, I knew undercharging/discharging a Li-ion does extend life cycles, but didn’t know by how much. 1200 cycles is epic! I’ve been charging mine up to 4.1V and stopping the discharge when hitting 3.2V, according to the discharge curves lygte-info measured some years ago on my LG MJ1 that would mean about 3000mAh capacity so 85% of their nominal 3500mAh, but I don’t know how much that would mean in terms of extending their lifetime. Is there a table for that or something?

Anyway, I’m pretty sure this “50% reduction in capacity to reach 1200 cycles” is not what XTAR is doing, as they would need a 5000mAh cell to begin with and AFAIK there’s no such thing in terms of AA-sized cells.

I too would be interested to know if the MC3000 can be configured to charge these 1.5V cells.

EDIT: the Operating Voltage Range of the MC3000 is 0.2 to 5.0V per slot - so I take it that the MC3000 could be configured for the new 1.5V cells unless something in the rest of its program rejects these 1.5V Li-ion cells.

Although I take @SammysHP point that you could charge them with a USB cable and magnets

I doubt that it will work. It has its own charging controller and just needs constant 5 V to work properly.

That would probably suck big time, given that a USB port (ie, without proper negotiation) won’t supply more than 500mA, and I doubt it very much the charge controller inside the battery would implement that.

If a programmable charger like the MC3000 can’t be made to work, I think the best option would be a power supply capable of providing 5V with as high a current as this battery would take.

OTOH, XTAR indicates the battery takes 2.9h to charge… as they also list a 4150mWh capacity, this works out to 4150/5/2.9= 286mA, so unless the charging process is horribly inefficcient, probably this battery won’t take more than 500mAh anyway.

I tried here and at least with my unit (Firmware Version 1.17, Hardware Version >= 2.20) I can’t set target voltage any larger than 4.40V with any battery type, either directly via the charger panel or the app (haven’t tried with the PC software).

… so special charger, as originally suspected. These cells are not so attractive.

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Maybe less so as it looks like they are close $6.50 per… when buying 4. $5.50 each for 8. They will have to be awful darn good for that price.
Better than the specs say…

BTW, the LC4 charger is rated to supply 0.5 A for charging each cell. It also claims TC-CC-CV three stage charging.
Why when the cells have a BMS?

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And some of the specs sound really ‘optimistic’ to boot (like the 1200 cycles of expected life)…

Well, still waiting for someone to buy and publish an in-depth review. But as it doesn’t support an intelligent charger like the MC3000, it’s going to be a PITA to test it for some of these specs (specially the loss of capacity after many cycles).

maybe it’s not a full blown BMS…

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I bought the charger and 4 cells for $30. Just to check them out. I have a couple of things that they “might” be good for. Indoor Temp/humidity transmitters for the weather station.

I wonder if I can’t use the MC3000 for discharge/capacity testing… even if not for charging. I will have to try it.

It is well beyond my patience level to try to test the things for 1200… or even 500 cycles. If the AAs work out, I can use 8 of the AAAs for some other remote units. I have been using the Energizer lithium primaries… (claimed to be ~3500 mAh) which are not cheap either. If these work out and give anywhere even close to the runtime, and even if I only get 100 cycles, they will pay for themselves.

When I can get some numbers, I will post them here.

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I think it should work. Perhaps even for charging as a LiIon4.35 (which allows target voltage to be set to 4.40V) as long as the embedded circuit isn’t too anal about it.

Good thinking. I use them Energizer Ultimates too and they’re not cheap… but I don’t think these XTARs, being li-ion based, would work for me instead (I use them on outside thermometers which are often exposed to very cold temps – which is where Lithium primaries excel, and other chemistries including Li-Ion rechargeables suck).

When I can get some numbers, I will post them here.

Looking forward to your report!!! :partying_face:

@dmenezes @Mandrake50

Very interested to see any numbers. As has been discussed above, a major use for these 1.5V Li-ion cells could be as a replacement for (Energizer) lithium primaries.

Too bad they apparently can’t be charged in a MC3000. I don’t mind the small cost of the special (XTAR LC4) charger, just the extra clutter. At present I can charge ALL my different cells for lots of different items (not just flashlights) in an MC3000.

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Just be careful about cold temps performance – eg, my LG MJ1 at 0 Celsius loses 20% of its capacity, and 30% at -10C; at -20C and lower it shouldn’t even be used lest it be damaged.

May sound radical, but I have a temperature sensor inside my fridge which has to use Lithium Primaries exactly because of that.

It is interesting solution. Lithium battery with integrated step down converter?

Yes @dmenezes I see that. I admit I was not thinking about really low temperature performance (we don’t have any of that, ambient-wise, to speak of here in Oz). I had more in mind their - both lithium primaries and these new 1.5V-Li-ion cells - use in apparatuses where you just don’t want to replace the battery any more often than you (me anyway) really have to. Such as Weather Stations and remote thermo-hygrometers.

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This is exactly what I am considering them for. The sensors that I will use them in are indoor sensors. So I am not worried about ambient temps being too low. If they are… I have more serious problems. One takes 4 AA cells and 4 of them take two AAA cells. Meaning quite a few Energizer Ultimate cells every 6 months or so. I will stay with the Energizers (4) for the outside unit. It definitely does get lower than -20C here at times in the winter. Very rarely even -30C.
I have tried eneloops in the indoor units, but the main sensor uses 4 AA cells. It will quit when the 4 eneloops are still around 1.3 volts per. Those cells will still work for a long time in many devices. So instead of changing batteries every 8 to 10 months, it is like 3 to 4. If these cells give me 6 months or so, it will be worth it. AND, cheaper in the long run.

I just wonder whether I can get meaningful capacity tests using either the MC3000 or the C9000 chargers that I normally test NiMh cells with,

Ouch! What sensor is that? I use this one, works like a charm and has opensource software available for it that can read it over bluetooth and post the data eg in HomeAssistant: https://www.amazon.com.au/Xligo-Bluetooth-Temperature-Thermometer-Hygrometer/dp/B07FY5SPLG

Uses one AAA, and using a normal (non-Pro) Eneloop, lasts over 6 months – except in cold temps where it lasts about 3 months. Not weatherproof, so for outside use I place it inside a ziplock bag (which probably screws the humidity reading, but I don’t care too much about humidity anyway). In both cases, when I remove the cell and measure it, the battery’s voltage is at about 0.8, so I guess it really sucks them batteries dry.

The 4 AA sensor is a 15 to 20 year old Oregon Scientific unit. Temp, humidity, pressure. The “main” indoor unit.
I have to say that the entire system still works well. Newer ones that have similar features are quite expensive. So I deal with the battery issue.

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