Battery performance degrading?

I’ve used pen style vapes for years, small Kanger tanks with Kanger and Vision Spinner batteries. Also a few standard mods with 18650 batteries that never leave my desk. With all of these I keep a log of how much juice is used in order to monitor coil and battery longevity.

In the past 3 months I’ve ordered replacement batteries, and they are all under performing older batteries by 30% to 50%. I’m fairly confident the new batteries are “original” not clones. Both the Kanger and Vision units look original and pass the scratch off verification codes. The 18950 batteries came from IMR, a reputable vendor.

Google hints at 2 theories. One is just “shrinkflation.” That the decreasing supply of lithium is prompting manufacturers to simply put in a little less. The other is more complicated. It is widely reported that lithium batteries drain slowly when not in use. And that when drained and left uncharged for a long time, lithium loses its ability to recharge. So, if batteries sit in a warehouse for a long time they may drain and die.

My old 1600 mah Kanger and Vision batteries reliably process 2.7 to 3.0 mils of juice. The “identical” new batteries only handle 1.3 to 1.7 mils. Same juices, same coils, same settings. Anybody else seeing this phenomenon?


I haven’t noticed this with my 18650 batts.
However I do have some newer ones purchased in the last year that I have not begun to use yet.
I do charge all my batts to 3.7 volts around every 6 months or so to help with the longevity.
I also don’t charge any using more than .25 amps and I never charge them in a mod.
What I have read it gives the batts a little more lifespan.
It seems to work as I have a dozen or so of some Sony’s and Samsung’s still in use since 2017.
I’m going to charge a new set today and see if I get the result you are getting and we’ll see what happens in a few days


I have a fancy multi charger / tester that tells you exactly how much charge a battery is taking, and you can also have it drain a battery for you and monitor its output. Be interesting to test out a few fewer batts and see if they meet their specs at all.

but yes, but those theories are quite possible. they dont build them like they used to. and yes like most thing if they just sit, they slowly die. especially if they sit in a discharged, or over charged state. lithium batteries are most comfy at around 70% full.


You say a new “identical” battery is under performing your older batteries. So you have the specs for both old and new batteries?

Battery package:. i.e. 18x50, etc.
Voltage: 4.2V
Capacity: X mAh (Miliamp-hours, i…e. 4200mAh)
Maximum Continuous discharge rating: in Amps. Usually between 10A-45A

Are the specs written on the batteries? Most of the times only the Voltage and Capacity are written on the wrapper.

Usually if the capacity is on the low side, 2000 to 3500, it will be a high current battery, 25A to 45A. If the capacity is on the high side, 3500 to 5000, it will be a low current battery, 10A to 20A.

You may have old batteries that are high capacity and your new batteries are a lower capacity. That would explain why they appear to be under performing. If you idea of battery performance is only about how long a charge lasts than it would sure seem that way to you. Maybe they outperform the older batteries when it comes to how many Amps they can pull without exploding!

If you vape a proper coil build with your 5000mAh 10A max battery so as to always stay at the 10A or below max discharge rating you will have a combination that lasts for days on a single charge. If you vape the same coil but use a 2000mh 45A battery you will definitely stay well below the safe discharge but you battery will only vape for less than half the time.

IMR only sells good batteries but you can get different rated batteries of the same manufacturer and form type from them, same as from any battery dealer. My preferred battery dealer is and my preferred brand is Molicel. I keep the high Max discharge batteries around due to my style of vaping and the capability of most of my hardware.

I recommend writing the specs on each battery wrapper, I make labels for mine. That way you never forget or mix up batteries. You want to know the specs so you can use them along with Ohms law calculations so as to never blow your face off.

@Redcrown If you already know this it’s still good to have in the discussion for other people that are still learning.