confused over battery sizes

[hyperloop]

Hi all, i've been looking at the Drake, Draco, Wee and other similar tiny lights. And i think i have gotten this weak brain of mine wrapped around the concept of CR2 batteries, but what are the differences between CR2, 10280 and 10180 cellss??

What options are available for me to get rechargeables in these sizes? Can they fit in my Ultrafire WF-139 if i use 2 spacers??

Thanks in advance.

 

[DM51]

CR2 are 3V Lithium primaries. The 3.7V Li-Ion rechargeable version is a RCR2, or 15266 cell.

Li-Ion cells are often denoted by 5 figures. The first two are the diameter of the cell. The next two figures are its length (both these measurements in millimeters). The last "0" just means it is cylindrical.

So the 10280 is 10 mm diameter, 28 mm long, and the 10180 is only 18 mm long.

You must not charge tiny cells like these in a WF-139. The rate of charge is far too high for them.

 

[mdocod]

Many of those tiny lights can be fun, but keep in mind that many of them are really destructive to the tiny li-ion cells they often call for. A 150-300mAH cell should not be discharged at 500-1000mA like so many of the small lights do. Also keep in mind that none of the small li-ion cells are protected, so the user is responsible for preventing over-discharge, and using a charger that will not over-charge.

 

[hyperloop]

thanks for the replies, i guess i will just get a dedicated charger and some RCR2s, which would you recommend? 3.0v or 3.7v? I'm contemplating that Ultrafire light on DX which can either go CR2 or 2 x AA

 

[mdocod]

if the light will support it, get a 3.7V style cell as you will have more watt-hours to work with. I'm not sure if 3.0V rechargeable RCR2 cells even exists, then again, I have never paid much if any attention to that segment of the market....

 

[hyperloop]

noted with thanks