EagleTac G25C2 MK2 + 18650 3400MaH cell= FAIL!

Shaysrebellion

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I really like this light and I ordered the biggest battery I could find but it fails to come on. It does work with the 3100MaH battery but the 3400MaH is too long. The tail cap will not screw down enough to touch the body. Its funny because the body tube is wide enough for a 4,000MaH and the 3400MaH battery actually slops around side to side. The battery comes all the way up to the back of the body tube.

ET needs to make a deeper tailcap or a longer body tube but in the current state it fails.
 

shelm

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Is your tailcap the one with the pin instead of bare spring?
 

Shaysrebellion

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Is your tailcap the one with the pin instead of bare spring?

Yes, but the pin is spring loaded and pushed back.

I also tried putting a small magnet on the + end and ended up crushing the + end of the battery in to a concave pit. UGH!! The battery does still work in my SWM V20C fortunately.
 

bemymonkey

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Which 3400mAh cell did you buy? Sounds like the protection circuit PCB may just be too thick...
 

RedForest UK

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What do you mean by 'wide enough for a 4000mah battery'? Capacity in 18650 cells is not really correlated to size, there are also no genuine 4000mah cells available right now, only cheap ones claiming that much but which are actually between 500 and 2000mah. Panasonic have one in the pipeline but that will be the same size as their 2900, 3100 and 3400 mah NCR18650 series.

The key differences in size of an '18650' are in the size taken up by the wrapping and PCM added to the base cell. By definition the base cells of all 18650s must be 18mm wide and 65mm long.

I assume that your 3100 and 3400mah cells are sold under different brand names? But both will have the same size Panasonic cells inside NCR18650a and b in the 3100 and 3400 respectively.

Can you say which brands are on the labels of the different cells you are referring to?
 

shelm

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Yes, but the pin is spring loaded and pushed back.
Some Eagletac tailcaps (pin-style) suffer the problem that the pin cant be pushed back fully. If you compare 10 units, you'll find out that on some pin-style tailcaps you can push the pin further down, and on others you cant.
 

Shaysrebellion

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What do you mean by 'wide enough for a 4000mah battery'? Capacity in 18650 cells is not really correlated to size, there are also no genuine 4000mah cells available right now, only cheap ones claiming that much but which are actually between 500 and 2000mah. Panasonic have one in the pipeline but that will be the same size as their 2900, 3100 and 3400 mah NCR18650 series.

The key differences in size of an '18650' are in the size taken up by the wrapping and PCM added to the base cell. By definition the base cells of all 18650s must be 18mm wide and 65mm long.

I assume that your 3100 and 3400mah cells are sold under different brand names? But both will have the same size Panasonic cells inside NCR18650a and b in the 3100 and 3400 respectively.

Can you say which brands are on the labels of the different cells you are referring to?

Uh they are bigger. Take a 2,000 mah AW and compare the diameter to a 3400 ET battery. One will fit in my zebralight and one is way to large in diameter.

I was joking about the 4,000mah based on the extra ID diameter of the ET g25 as its huge and sloppy and the 3400 rattles around side to side about 1/8th of an inch.
 

Vortus

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Odd as ET batteries are some of the shorter ones. Brands do vary somewhat in both length and width. There is a post in cpf that measures about 10 or so assorted brands on all specs ranging from dimensions to output. Pretty surprising. I have to use magnets on my ET batteries with some hosts. Not on ET lights though.
 

oKtosiTe

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Uh they are bigger. Take a 2,000 mah AW and compare the diameter to a 3400 ET battery. One will fit in my zebralight and one is way to large in diameter.

I was joking about the 4,000mah based on the extra ID diameter of the ET g25 as its huge and sloppy and the 3400 rattles around side to side about 1/8th of an inch.

Odd as ET batteries are some of the shorter ones. Brands do vary somewhat in both length and width. There is a post in cpf that measures about 10 or so assorted brands on all specs ranging from dimensions to output. Pretty surprising. I have to use magnets on my ET batteries with some hosts. Not on ET lights though.

He said diameter, not length. :p
But indeed, as the linked post shows, battery size is not obviously correlated with capacity.
Here you go:
HKJ's 2012 Battery test/review summary
 
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Up All Night

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Diameter BS aside, as this thread is about the OP's battery being too long. I wonder if you could provide the actual length of your 3400 cell. Eagletac advertises the length of the 3100 to be 68mm with a button top and the 3400 isn't on their site yet(surprise!). I assume the 3400 cell, of which you are referring is an Eagletac? Flat or button? the only pic I've seen looks to be of the flat top variety. Big goof on ET if their 3400 battery doesn't work in one of their more popular lights!
 
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