When to buy new 18650 batteries?

[Kanthal]

I've got 4 purple Efest 35A 18650s that I bought in April of this year and have been using those 4 batteries in rotation ever since.

I was just wondering what are the first signs of needing new batteries?

My batteries still hold a full 4.15v to 4.20v when fully charged. The wrappings on the batteries still look good as new too, but for some reason I feel as if the batteries don't have the same power as they did when they were brand new. It could be my imagination telling me they are getting weaker just so I can go and buy more batteries, or they could have in fact lost the power they once had.

I'd like to get a few opinions on how to know when it's time for new batteries.

 

[yzer]

I have used a set of four Efest red IMRs since April of 2013. The first sign that the battery is giving up the ghost is loss of capacity. I use these in a Sigelei Zmax V5 with a carto tank. Of the four 18500s one battery was done for a few months ago and the other three are still doing just fine.

The Sigelei V5 has a puff counter. I keep track of how many puffs I get from each battery before it hits 3.2V and needs recharging. I run about 325-350 puffs on each battery time after time.

The Efest that failed started to hit 3.2V after about 300 puffs late last summer. The puff count dropped quickly after that and after about 20 more charge cycles it wasn't getting 150 puffs anymore and I tossed it. It did about 270 charge cycles before reaching this stage. The other three Efests in the set have gone over 325 charge cycles and are still performing strong.

I have charged these bateries with a Nitecore Intellicharger i4.

 

[yzer]

Even after 325 charge cycles my red Efests still look great with no wear evident on the wrappers. The + and - battery terminals show scuffing from use but that is to be expected.

 

[Hitmetwice]

I get a new battery whenever I notice one that holds a charge for consistently shorter periods of time.
I don't ditch them right away, just put more into the rotation.
I have 5 IMR 18490's in rotation and 2 of them are the 2 that came with my Provari almost 3 yrs. ago now.
Never hurts having a back-up around even if it's only good for a couple hours.
A power user will certainly go through a lot more a lot faster.
I'm only a 4 volt vaper.
Life cycles will be shorter for power users for sure.

Cheers.

 

[KTMRider]

Typical LiIon batteries will last 300-500 cycles.

 

[Ryedan]

I've got 4 purple Efest 35A 18650s that I bought in April of this year and have been using those 4 batteries in rotation ever since.

I was just wondering what are the first signs of needing new batteries?

The first sign I got was lack of power in mechanical mods at around 0.5 ohms. Voltage drop under load goes up as internal resistance goes up. I noticed this before I noticed run time go down per charge. With regulated mods you'll probably notice run time reduction.

My batteries still hold a full 4.15v to 4.20v when fully charged. The wrappings on the batteries still look good as new too, but for some reason I feel as if the batteries don't have the same power as they did when they were brand new.

The voltage after charge stayed at 4.2v with mine. There is a huge difference between 4.15 and 4.20. Mine are always between 4.20 and 4.21. They will go down 0.01 after a few hours though, so measure them close to when they are finished charging.

 

[klynnn]

I have about 20 batteries and rotate through them so they get used once or twice a month . Some I've been using since 2012 and still are going strong.

 

[Rat2chat2]

Here is also some very good information on this battery that I hope will help also.

Test/Review of Efest IMR18650 2500mAh (Purple) 2014

Not sure if this will have the information you are looking for but. . .

https://www.youtube.com/watch?v=zlUhaZFfAaQ

Good luck to you and happy vaping.