EagleTac T100C2 + Tenergy 18650 = No Light?

ResQTech

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Anyone use the EagleTac T100C2 with a Tenergy 18650? Seems like the (+) end is pretty flat and isn't making contact? Are the (+) ends of all 18650's flat?
 

Yucca Patrol

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Some of my Tenergy 18650's have flat positives and some have raised ones. The ones that came from 4-Sevens were raised and the ones I bought from all-battery were flat.

Some people use very thin magnets to raise the positive end to make contact.
 

bigchelis

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Anyone use the EagleTac T100C2 with a Tenergy 18650? Seems like the (+) end is pretty flat and isn't making contact? Are the (+) ends of all 18650's flat?


I purchased the same cells from battery junction and even with magnets I couldn't get them to work. They all read 1.4v. I have to check if they give voltage in series when I get home to see where the issue is.


You need magnets; good luck. I know I need it.:ohgeez:
 

Mjolnir

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Your 18650's read 1.4 volts? That is WAY too low, and they are probably beyond repair.
The reverse polarity protector on the Eagletac is a physical protection. I believe it has a raised lip around the positive contact that prevents the flat negative end from touching the positive contact. However, this means that batteries that have 2 flat sides will not make contact. Most protected 18650s are not flat topped, but apparently Tenergy still makes their protected cells with flat tops.
 

richardcpf

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Anyone use the EagleTac T100C2 with a Tenergy 18650? Seems like the (+) end is pretty flat and isn't making contact? Are the (+) ends of all 18650's flat?

Mine doesn't work neither. Both ends are flat.
 

ResQTech

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Where would I get these magnets? I thought I saw something about using caution with Li-Ions and magnets...? How about a solder blob on the bezel contact?
 

Mjolnir

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You could try these:
http://kaidomain.com/ProductDetails.aspx?ProductId=2658
The issues I have heard are of the magnets making contact where they shouldn't and shorting out the battery somehow. A magnet might affect the circuitry in the light or in the battery, but this depends what sort of electronics are inside. I don't think that it is likely that the magnets will affect the circuitry on the PCB or in the head. Magnets are most harmful to magnetic storage devices like hard drives, but I doubt you will find any in batteries or flashlights (flashlights use "flash memory," of course! Ok, maybe not...) It would probably be better to solder something to the battery and not the head, since the bezel contact is gold plated. I don't think you really want to ruin the gold plating by putting solder on it. It could also interfere with the low/high switching mechanism.
The safest option would be to get some non flat topped batteries.
 

ResQTech

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It would probably be better to solder something to the battery and not the head, since the bezel contact is gold plated. I don't think you really want to ruin the gold plating by putting solder on it. It could also interfere with the low/high switching mechanism.
The safest option would be to get some non flat topped batteries.

Oh well... I soldered the bezel contact. The gold plating makes no difference if there's a magnet there too. I already have the batteries and don't want to go through the hassle. The solder blob works great and the Tenergy 18650s work perfectly now!
Here's a pic:
IMG_5368.jpg
 

bigchelis

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Your 18650's read 1.4 volts? That is WAY too low, and they are probably beyond repair.
The reverse polarity protector on the Eagletac is a physical protection. I believe it has a raised lip around the positive contact that prevents the flat negative end from touching the positive contact. However, this means that batteries that have 2 flat sides will not make contact. Most protected 18650s are not flat topped, but apparently Tenergy still makes their protected cells with flat tops.


My apologies; I thought the OP was referring the the NiMH 18650's.
 

Mjolnir

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Well the point of the gold plating on the contact is to prevent corrosion, not reduce resistance. Soldering it would probably nullify this protection.
Out of curiosity, what made you choose the tenergy batteries over others? I am pretty sure that they are non flat topped protected cells with equal or greater capacity.
 

ResQTech

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Well the point of the gold plating on the contact is to prevent corrosion, not reduce resistance. Soldering it would probably nullify this protection.
Out of curiosity, what made you choose the tenergy batteries over others? I am pretty sure that they are non flat topped protected cells with equal or greater capacity.

May be a stupid question but, why would the inside corrode unless it was subjected to moisture? The only time I've had a corrosion problem was with a mag when the batteries leaked...

Anyway, chose the Tenergy because of this post that I read:
https://www.candlepowerforums.com/posts/2906093&postcount=1

<snip>
I have chose for runtime a TIABLO A8 which is regulated on 18650
With a 18650 AW rated at 2200 mA and an protected grey ULTRAFIRE 18650 I got 100-105 min of runtime for each of them
With a 18650 TENERGY rated at 2600mA I got a runtime of 130 min !!??
<snip>
 

Mjolnir

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Well running batteries in a light isn't the best way to test batteries, since not all batteries keep their voltage as well as others, and the light might not be truly regulated. It is doubtful that someone could notice slight dimming without a light meter.
From looking at some posts, it seems like the tenergy cells are around 2100 Mah, which is about the same as the trustfire "2500Mah" cells. The tenergy's could have more capacity, but I don't really know for sure.
I'm not sure why the inside contacts would really need to be protected from corrosion. I think the gold plating might be more of a marketing thing, but i'm not really sure. If the contacts are aluminum I don't know why they would oxidize or corrode, but if they are some other material they might.
 

hsotnicam

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You could try these:
http://kaidomain.com/ProductDetails.aspx?ProductId=2658
The issues I have heard are of the magnets making contact where they shouldn't and shorting out the battery somehow. A magnet might affect the circuitry in the light or in the battery, but this depends what sort of electronics are inside. I don't think that it is likely that the magnets will affect the circuitry on the PCB or in the head. Magnets are most harmful to magnetic storage devices like hard drives, but I doubt you will find any in batteries or flashlights (flashlights use "flash memory," of course! Ok, maybe not...) It would probably be better to solder something to the battery and not the head, since the bezel contact is gold plated. I don't think you really want to ruin the gold plating by putting solder on it. It could also interfere with the low/high switching mechanism.
The safest option would be to get some non flat topped batteries.

These little magnets are confirmed to work with Tenergy 18650 and Eagletac T100c2.
The magnets that I got from Kaidomain are much smaller than I have expected. It's about 1/9 of the area of the metal contact of the battery.

The magnets do move around on the battery, but, because of the structure of T100c2, the three pieces (the battery, the magnet, and the head) are always in contact, even when the magnets are at the edge. The ring like structure in the head stops the magnet from moving any further.

The greatest part is, it costs .99 from Kaidomain with free shipping, and the shipping costs them $3. :crackup:
 
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