my primary cells are brighter than AW

[abarth_1200]

by the looks of things it appears that my cheap primary cells are brighter in my TK11 than the brand new AW 18650 cells i got this morning.

Using an ultrafire W139 i put them on charge and the the leds lit up red and blinked green every few seconds, after about 2 mins they stayed lit up green, does this mean they are charged.

Also my TK11 gets hotter using primary cells than using the rechargeables... does anyone know whats going on here.

im new to lithiom ion so dont want to go blowing anything up

 

[Mr Happy]

Yes, I would guess it is because two CR123A cells provide about 6 V, whereas one 18650 provides about 3.6 V. The light is brighter on the higher input voltage of the primaries, and because it is running with more power it follows naturally that it gets hotter.

 

[abarth_1200]

thats a bit dissapointing i thought i bought a 225 lumen torch capable of that output to find that it works brighter on primary cells.

does anyone know if i can leave my batteries on charge after the green light stays on, i have taken them off for the meantime just incase

Thanks anyway mr happy... have a happy day

 

[Mr Happy]

Well I haven't looked in the LED forum where this light is doubtless reviewed, but perhaps it is 225 lumens on the 18650 and more than 225 lumens on the primaries? It seems like the TK11 is mainly designed for the 18650 and the primaries are the backup option.

What sometimes happens with lights containing a boost circuit is that they go into direct drive when the input voltage is high and drop into regulation as the batteries run down.

If I were you I would run the light on the 18650 and enjoy long life and happy lighting.

 

[mdocod]

beginning to wonder if the TK11 is just using the same circuit type as their TK10, but with the low-battery indication disabled so that it'll direct drive from an 18650, I haven't seen any charted output/runtime plots on the TK11 by independent sources so it's hard to say, this has been very common practice for lights that use an 18650 to not actually run in regulation on an 18650.

I would personally take some tail-cap current readings if possible, ideally, a reading with the 18650 at full charge, and one with it lower, like reading around 3.8V open circuit, If the reading at 3.8V is lower than the reading at 4.2V, then it is not regulating the output on the 18650 very well, if inlet current rises on lower input voltage, then it should be regulating properly, also check on the primaries and make sure it isn't running abnormally high or anything. Shouldn't be any more than around an amp I'd think, probably less.