Test/Review of Xtar 18700 2600mAh (Black)

Batteries and Chargers Rechargeable Batteries
1

Xtar 18700 2600mAh (Black)




Official specifications:

  • XTAR 18700 2600mAh Protected Li-ion Battery
  • Voltage: 3.7V
  • Battery Capacity: 2600mAh
  • Cell: Sanyo lithium cell inside
  • Size(mm): 70 (length) x 18 (body diameter)
  • Net Weight: 48g




The battery is called 18700, because it is nearly 70 mm long, but protected 18650 can be just as long, only unprotected batteries are 65 mm long.








This battery has a high voltage at low loads.











The two batteries has slightly different internal resistance and trip current (This might be related).





Conclusion

The high voltage can be an advantage in smaller (i.e. 3-4 watt) lights where the battery replaces two CR123 cells.
It is a very good battery.



Notes and links

How is the test done and how to read the charts
How is a protected LiIon battery constructed
More about button top and flat top batteries

2

i think i have these cells (purchased from HKE). a 2-pack. i seldom use my 18650 torch.

Thanks for the review, great job as always!! :)

3

I have 2 Xtar 18670 2600, but their wrapper has red letters... is there a coloring scheme to each production run? I would like to know which cell was used without dismantling the battery. Does anybody know?

4

Thanks for the review!

I have bought quite many of previous red-labelled Xtars and also these newer ones.

I had a small hunch from discharging tests, that these have " a steep knee " in discharge curve and thus should be a good option for a single 18650 -light.

Good results 8)

5

Thank you HKJ. Encouraging to see Xtar maintaining production quality.

6

Thanks!

7

The red letter label of the 2600's changed to purple for some reason. Also some of the purple ones have been reported to have a slightly larger diameter.

Thanks for the review of these. I know a lot of people have been buying these through the group buy (including me).

8

I did some monitored testing of one of these (red letters) and according to the graph it should cut off when voltage drops to something like 3.4-3.3. But I chickened out when the multimeter read 3.26 and the light was still on.

I’ll try and mark that battery and see if this little torture will affect its life/performance.

9

Remember that if the current is too low you may not trip the PCM. Also if the current is high enough the voltage will bounce back significantly when the current load is taken off, so while it may measure 3.26v with the light on it may bounce back to measuring 3.5+ after a minute or two of switching it off.

10

My little test was a little more low-tech, I had my UF-C108 on high for 5-10 minutes at a time, took the battery out and tested it, so I didnt do any readings while the light was on per se. Time from light off to measurement was the time it took for me to unscrew and take the battery out, maybe 20 seconds.

I’ve maybe been reading a little too much on that other forum regading battery safety and explosions and stuff, so I was cautious not to over-discharge the cell, even if the protection should take care of that.

11

The battery does not cut off, but because the capacity is nearly exhaust, the voltage will drop. When you turn off the light or remove the battery the voltage will immediately increase.

The PCB protection will trip somewhere below 2.8 volt.

12

Oh I see. I thought it tripped at 3.4. The light didnt dim at all until the very last moments before I decided to rescue the battery. How far do you let your batteries go before you charge them? I doubt many people carry multimeters with them…

13

I do very seldom measure on my batteries (Except if I suspect something is wrong).

Instead I just charge them. If a light reduces brightness I also replaces (or charge) the battery.

14

I have ordered pretty many of these, still with good results.
Qualitychinagoods seems to be pretty affordable place to get these, ordered 5 pairs and got them for 5.2USD/piece after registered shipping and PP exchange.

15

People buy lots of these cells for 3.86$/pc during Wallbuys Crazy Sale Hours, i see i see. Hey guys i dont recommend this product, I own myself 1 pair. The performance of the cell, Sanyo inside, is awesome.

But after ~1 year of storing in the case, hardly any use, the black wrapper gets all bad (decayed/brittle/fracturable) at the round edges of the cell, plus pole, minus pole. You know this phenomenon, fresh plastic is soft and flexible and strong, and old plastic gets hard, dry, fracturable. The reason for this phenomenon is the aging of the black wrapper material, its plasticizers diffuse out of the material and leave behind poor brittle cheap plastic foil. The wrapper is very thin too, which accelerates the aging process.

On my samples the plastic has chipped off little brittle cr*p at those exposed parts, e.g. the minus pole where the flashlight rear spring sometimes touches the wrapper, and i had to tape the round edges with scotch.

Feel free to buy as many of these cheap wrapper cheaply wrapped cells as you want, personally i dont care it's your money haha. It's good to support new merchants such as Wallbuys so i am buying stuffz from them too. Just take it as a warning, XTAR cells inside are awesome (Sanyo or Panasonic or Jap cells) but their wrapper really su*ks.

Much much better quality wrappers are the transparent wrappers of the generic protected Pannys (3100, 3400). Those wrappers are thick, tough, and ductile. Will last you many years without ripping or chipping.

And Eagletac wrapper quality? That's a whole different story. Eagletac cells are expensive and ..etc.. ;)

I will never buy XTAR cells again because of the poor quality XTAR wrapper. I am serious kreisler the most honest and critical shopper and flashlight user around. and trustworthy.

16

haha ha…Kreisler…I’m still up. Good catch on the Wallbuys….guess you get what you pay for when it’s cheap cheap !!