Thanks Djozz for the good info. Vapcell have been releasing some really top notch cells lately. They have the best cells of each size, this 16340, 14500 gold wrap, 18650 p26A/p28a and vtc5d/vtc6a,21700 p42a, and 26650 red wrapper that tested 59xx mah may same as the Shocklis
I purchased and tested a gold 14500 button top this evening. The discharge capacity was 966 mAh, with a charge capacity of 970 mAh’s at 4.18 volts.
The resistance was 103 ohms. Seems a bit high, especially in comparison to my Efest 14500 (29 ohms) and my EBL 14500’s (all four are 49-54 ohms). Thoughts?
I got the Xtra Dragon VP4 plus which uses probes to measure both voltage and resistance. All my other battery testing looks good, even a few button tops I have.
Prior I was using the Miniboxer C4-12 which is not accurate like mentioned.
Last time, when I ordered button top Vapcell batteries from the Vapcell AliExpress store, I got button top batteries with significantly increased internal resistance compared to the flat top ones of the same type. Can you confirm, that Vapcell have revised the method of applying button tops, or it is still not recommended to get button top battery if I would expect the same (or nearly the same) current specification for the selected battery?
And this is not a charger related problem, as I have reliable Samsung INR18650-30Q button top batteries, which has nearly same internal resistance reading in my chargers, as the flat top ones.
I received my Vapcell 16340’s today. I ran a 3 amp discharge test on the icharger from fully charged. I got 638mah at 12 min and 45 secs down to 3v.
Down to 2.75v, I got 726mah at 15 min and 25 secs. This test was done at a constant discharge of 3 amps and there’s no doubt this cell will make 800mah or more at a 1 amp or less discharge.
When I started the test the voltage stayed decently high. It started at 3.7v under the load and fell rapidly to 3.6v where it slowly crept down to 3.5v after about 3 mins. The cell done very well holding around 3.5v for awhile.
We have a new 16340 King, less sag and more capacity .
Thanks Vapcell for improving on these smaller size cells. Great Job .
Analyzing chargers usually are rather bad at measuring battery internal resistance. Contact resistance is easily burdened by oxidation or debris. I also guess you meant to say mΩ instead of Ω, don't you? ;-)
XTAR Dragon VP4 plus uses probes to measure resistance and they are accurate when comparing to my fluke. I’m assuming I got old stock before they upgraded their button top welding process.
I understand vapcell Dennis, but FaintReality reports twice the internal resistance of an EBL 14500 for his Vapcell 14500. I know his figures are far from real DC resistance values but to me that means his Vapcell 14500 is likely well above 200mΩ of internal resistance. So pretty bad. Being so removing the button top and using a rotary tool with a grinding bit to gently fix the welding remnants is a wise choice.
So although the Xtar may not be 100% accurate, it is more than sufficient to use for comparison sake, which raised a red flag when comparing the Vapcell to the Efest and the cheap eBay EBL batteries.
I would remove button top and re-wrap, but these batteries are for a Sofirn SF14 V2.0 which requires button tops. I may just do it out of curiosity sake…