Li-ion 14500 AA batteries

[jeffb]

I would like to use above, in a TNC AA, 200ma light and have read that others may use this combo. (There is another active thread that CY and others contributed).
I have searched TNC website as I believe he has sold these batts/ without success?
I also have a PILA charger for PILA Li-ions; am assuming that I would need a different charger? Any experience and help would be appreciated!
THANKS,

Jeff B

 

[cy]

I've been using 14500 in TNC AA and several other 1x AA luxeon lights for some time. you will need to add a small blob of soder to pill, make contact with flat top 14500 cell.

when vin exceed vf of luxeon, you are in direct drive less burden of circuit. draw was aprox 1amp for ARCmania pill. light did get warm with that much current to lux.

I don't know if TNC is saying it's OK to run 1i-ion with TNC AA by selling 14500. Also TNC Ncell uses the same pill. the AAA tube for TNC Ncell will accept the new AAA sized li-ion.

light output with 14500 TNC AA is very bright!!! same or more output as many larger 3watt luxeon lights.

I had no problems runing li-ion with ARCmania's pills, but you may be different. I cannot be responsible for you killing your pills.

foursevens was selling some li-ion charges a little while back. I'm using DougS's Li14430 charger for 14500.

 

[IsaacHayes]

These seem so cool. I wonder why they aren't more popular? You could pop one into a dorcy 1AA with the easy lux mod and have full power!!!

Or ream off the lip of a MM, press fit an aluminum slug HS into it with a 5w on top, use a 17mm IMS, and pop 2 of these DD and have a cheap & powerfull rechargable L4!!!!

 

[cy]

before I forget, if you have a ARC AAA or AA with chip problems.

insert a 14500 in ARC AA or AAA li-ion in ARC AAA. if chip was your problem, your light will now run at greater output.

but I've found most of the time intermitten problems are caused by batt leaking and corrosion forming on contact post.

again I've had no problems runing ARC AA on 14500, but your results may veri.

 

[Doug S]

[ QUOTE ]
jeffb said:
I would like to use above, in a TNC AA, 200ma light and have read that others may use this combo. (There is another active thread that CY and others contributed).
I have searched TNC website as I believe he has sold these batts/ without success?
I also have a PILA charger for PILA Li-ions; am assuming that I would need a different charger? Any experience and help would be appreciated!
THANKS,

Jeff B

[/ QUOTE ]
Use of a Li-ion cell without overdischarge protection [I do not know of any available 14500 cells that have it] in a light with a stepup converter that continues to operate at inputs voltages below 2.5V risks damaging the cell. The TNC AA light you mentioned will operate at input voltages below 1V.
Correct, the Pila charger is not suitable. Unprotected cells need a charger whose output voltage does not exceed 4.25V. 4.15-4.20V is much better.

 

[greenlight]

Sounds risky to me. Don't these explode?

 

[TrueBlue]

Any cell can explode given the right situation. Unprotected 14500 need protection- charger protection. NiMH and NiCad need charger protection too or they will explode.

14500 cells are safe if used responsibly. 14500 cells should be rated "R" for responsible.

 

[cy]

yes bare li-ion cells can explode under the right conditions.

for single cell aplications after checking out there is possiblity for a dead short. IMHO danger is pretty minimal.

if you check out the RC forums, fires etc start when charging at 1C+ rates. for multi cell packs that could be large amps.

possiblity of one cell dying and the rest of cells reverse charging are large rate doesn't exist in single cell aplications.

 

[Doug S]

[ QUOTE ]
cy said:
yes bare li-ion cells can explode under the right conditions.

for single cell aplications after checking out there is possiblity for a dead short. IMHO danger is pretty minimal.



[/ QUOTE ]
Cy, there is one significant scenario that you are omitting. That is charger failure. Gross overcharging is the surest route to explosion or fire with Li-ion cells. I suspect that some of the cheaper chargers around have not be adequately analyzed/designed to accommodate all creditable failure modes safely. I happen to know that you own at least one that was /ubbthreads/images/graemlins/grin.gif

 

[cy]

Doug, Thank you for pointing that out.

Since I'm using your fabulous Li14430 charger for all my li-ion's. I'm covered!!! /ubbthreads/images/graemlins/grin.gif