26650 at 3900mAh

[windmill]

Hi, not so long ago I've bought a 4Sevens Maelstrom S12 and with it I had to get a 26650 sized cell.

This flashlight is great, it has a very small form factor compared to it's huge output.

My only concern is in fact the battery type which does not seem to be available if not from the 4Sevens site.

I know I can always buy from them but I don't like to be forced to have just one and only supplier.

Does anyone know where to find similar batteries as the ones sold by 4Sevens?

 

[VegasF6]

Lighthound IMR 26650, AW IMR 26500, Battery Space IMR 26650 or LiFePO4 26650 (but with different charger), Deal Extreme 25500.

 

[windmill]

Thank you for the info.

Are all these cells unprotected? Do you think this might be a problem?

I see that the Lighthound IMR 26650 and the Battery Space IMR 26650 say to be using LiMN chemistry with a safer operation than a LiCo battery. Is this why they are not protected?

Which chemistry do the 4Sevens batteries use?

 

[monkeyboy]

My only concern is in fact the battery type which does not seem to be available if not from the 4Sevens site.

It is available

http://www.4sevens.com/product_info.php?cPath=53_57&products_id=2585

They have just upgraded the charger and battery. There was a minor issue with the charger which they have sorted out with the version 2. The battery has been upgraded to 4000mAh too. I'm sure it's an IMR cell.

 

[jasonck08]

I'm sure it's an IMR cell.

It's not IMR, it's ICR aka LiCo.

 

[windmill]

It's not IMR, it's ICR aka LiCo.

What are the differences between these two technologyes?

 

[Ardillakilla]

The ICR 26650 aren't protected and it doesn't seem to be a problem. The S12 appears to have a low voltage cutoff and the hobby charger I use won't charge beyond whatever voltage I set as the limit.

 

[jasonck08]

What are the differences between these two technologyes?

The cathode material. IMR = Lithium Manganese. ICR = Lithium Cobalt.

IMR's are often regarded as being a "safer" chemistry, and these cells are used widely in "high power" applications such as power tools and EV's. ICR's typically offer higher energy density and are used in consumer electronics (e.g. Laptops).

Either cell is a fine choice for the S12.

 

[Stephen Wallace]

The ICR 26650 aren't protected and it doesn't seem to be a problem. The S12 appears to have a low voltage cutoff and the hobby charger I use won't charge beyond whatever voltage I set as the limit.

Despite any circuitry built in to the S12 light, the 4sevens LiCo 26650 cells do in fact come with a protection circuit. No indication though of what exact features the cell circuit incorporates - for instance, whether it protects against over charge, over discharge, or over current.