Playing with the 10440 Li-ion battery and chargers and rates and

Well , been meaning to play with the 10440 for a long time , and havent finished as yet . as the results are here and there ...

Charging and discharging @ 300mAh

The cell chosen originally discharged for a capacity of 200mAh , so charging and discharging @ 300mAh = 1.5C , Discharged to 3v and charged to 4.2v

1st Discharge = 200mAh

2nd Discharge = 235mAh [ Capacity increased ]

3rd Discharge = 221mAh

4th Discharge = 215mAh

5th Discharge = 181mAh

6th Discharge = 169mAh

7th Discharge = 166mAh

8th Discharge = 161mAh

9th Discharge = 175mAh

10th Discharge = 161mAh

11th Discharge = 161mAh

12th Discharge = 167mAh

Wow ! its a nice downhill slide there for capacity @ 1.5C

Next I decided to back of the charge rate to 100mAh , and the Discharge to 200mAh and see what happened ..

1st Discharge = 187mAh

2nd Discharge = 202mAh

3rd Discharge = 195mAh

Just thought id post this while its fresh in my mind [ other things to worry about ] , I will keep charging and discharging as time permits , but the slowing down the charge and discharge rates will increase the time it takes ..

But I will continue charging @ 100mAh and discharging @ 200mAh to see where that goes , and then maybe do 100/100

What was the purpose = First to get some idea of 10440 behaviour and tolerance to charge / discharge rates [ anyone document this before ? ] To find out what if any charge rate is good or bad for the little 10440 , everyone + myself seems to quote 300mAh , wow , might have to be lower than that ... estimate .

And whether capacity is affected by charge rates / discharge rates ... and by how much .. [ more testing needed ] I thought 300mAh was a good place to start ...

So far 100mAh looks good for the charge rate , after I do some 100/100 , I will keep the 100mAh charge rate and increase the discharge rate ..

~200mAh??

cute little cell! ;)

( an Eneloop AAA has more than 800mAh, new. )

800mAh with 1.2V

10440 generally 250 to 280mAh capacity , dont think too many top 300mAh ...

Hi, Old:

I'm not familiar with these but judging from the size they are the Li-Ion equivalent to AAA batteries. If they have 1/4-1/3 of the capacity though, what is the advantage of using them? Just curious.

The li-ion 10440s (yes, exactly AAA size) actually contain about 3/4 the energy of the NiMH AAAs. You need to take the higher voltage into account. Total energy is voltage times current times time. The precise measurement requires integrating instantaneous current times instantaneous voltage over the entire discharge curve, but for a rough idea, you can just multiply nominal voltage times capacity in mAh.

To illustrate, consider a 3x18650 setup using 2400 mAh cells. If you put them in series, you get 2400 mAh at 11.1 volts; if you put them in parallel, you get 7200 mAh at 3.7 volts. Both configurations obviously contain the same energy.

So, bottom line, burn brighter, run shorter?

Exactly. You put them in an ITP A3 or similar light and people are in awe!

Yes, but that's not why one would choose Li-ion over Ni-Mh.

The output voltage is much closer to the forward voltage of most LEDs, and therefore no boost circuit need be employed. This leads to fewer losses, and a more efficient light, overall.

The other side of the coin is one of power delivery. While Ni-Mh can deliver good power, it would require a boost circuit or multiple cells to achieve what one Li-ion or IMR can deliver, amp-wise.

Direct drive is how tiny lights like the iTP A3 can blast out over 200 lumen for a short time.

There are other considerations, but these were the first to come to mind.

which 10440's did you use for the discharge tests?

Generic Ebay supplied ????

I ran out of time , to keep cycling .. I did order some new ones but not sure where they are ? HK seems a little slow around Chinese New Year

generic? lol.

must be the blue Ultrafire then, huh..

They are the most popular 10440 cells. Why popular? Because of their availability.

as said above, when you run one of these in an ITP A3, or similar, it is nothing short of amazing.

true, it then no kidding even beats the Quark X AA 1x 14500 on High-mode.

the only downside is the runtime: the iTP A3 XP-G R5 runs only for max. 3 - 14mins before it reaches the 2.75V mark (protection PCB trips!). The runtime depends on the temperature of the little torch (and its 10440 cell). With optimal conditions you get the 14mins of runtime, i've clocked it.

Since the iTP A3 doesnt support protected 10440's (well, you need 2 rings to make the Protected grey Ultrafire 10440's 47.1mm work reliably in the iTP A3 Aluminum version) the only practical sense/use is imho to show it off in front your folks. That's actually a very good and sensible practical use hehe