Major battery life anomaly

[Moonbogg]

Ok, so I have two 18490's and two 18650's for my Provari 2.5. I used to switch exclusively between the 18490's before getting the 18650 upgrades, and the 18490's would last from about 7am to about 8pm. I would switch between the two batteries every day, not giving them much rest between charging and reuse. Now the 18490's have been charged and they had a good break for a few days and this 18490 has lasted from 7am and its now midnight and it isn't even blinking yet. It has lasted way longer than it used to. Is this increase in charge life due to the break between charges?
I thought a break between charges was only good for prolonging overall battery lifespan, but this seems to have seriously increased its useful time for each use.

 

[440BB]

I've read about giving batteries some time to "rest" chemically after charging, and mine get a half hour or so. Getting such a big increase as you are is surprising and unusual!

 

[Moonbogg]

The 18490 seems to have lasted as long as the 18650. The only thing I now for sure is that I'm totally confused. Maybe its the build in the kayfun affecting performance time and I mistook that for something else happening.

 

[classwife]

Moved to Batteries and Chargers from APV Discussion

 

[Ryedan]

The 18490 seems to have lasted as long as the 18650. The only thing I now for sure is that I'm totally confused. Maybe its the build in the kayfun affecting performance time and I mistook that for something else happening.

I agree with 440BB, I doubt the time off for the batts is all that's at play here. The voltage set on the Provari, the resistance of the coil and the number of puffs you take all contribute. I think the regulator is also more efficient at higher ohms and volts even at the same watts so that's also a factor.

It's easy to do the experiment again with more control this time. If you decide to do that, have fun and let us know how it goes

 

[Moonbogg]

OK experiment in progress. Same voltage setting on Provari, same kayfun build. Yesterday when I put the fresh 18490 in, I checked voltage on provari under load and it said 4.1v. The 18490 lasted from 7am until midnight and only then started blinking about 3.2-3.3v/

Last night I put a fresh 18650 that had been fully charged and resting for well over a day. Fresh voltage reading under load on provari was 4.0v. I've only taken a few drags off it and already its down to 3.8 volts reading on provari. When I unscrew the kayfun, the voltage reading goes up to 4.1v. The voltage drop under load is greater for the 18650 with provari extension cap than with the 18490.

I'll use it until it blinks and see where I end up as far as run time goes. It seems the 18650's start off with more voltage drop under load and almost seems that they aren't even getting a full charge or something. It doesn't seem right for sure. I'm using that cheap charger from provape for $18.00.

http://www.provape.com/Standard-Charger-p/s1mix.htm

EDIT: Um, ok. Something wrong here. This thing is already down to 3.7 Something isn't right at all. I've been vaping lightly and at this rate it will be dead by noon.

 

[Baditude]

A question and a comment:

What was the source of the AW 18650 batteries? Unless purchased from an authorized AW dealer, they could be counterfeits and be an inferior battery.

If all are authentic AW batteries, the 18490 AW's have a 16.5 amp continuous discharge rating (15C). The 18650 2000 mAh AW's only have a 10 amp continuous rating. The higher amp rating of the 18490's could allow for less voltage drop because of their higher amp reserve.

My

 

[DaveP]

I have 8 batteries that I rotate. There are 2 18650 Efest 2200mah (black and silver), 2 18650 Efest 2500mah (purple), and 4 AW 18650 2000mah (red). The Efests are only a few months old and the AW's are about 2 years and 4 months old. There's probably a 20% vaping time difference in the old and the new. I get vaping time from about 7am to late afternoon, maybe after supper on all of them, but the AW's seem to need charging an hour or two before the new Efests.

There's a caveat. I watch my voltages and try to swap them around 3.5v and put them in the charger. That's where the longevity comes in. Those old AW's have been treated that way since they were new and over two years later they are vaping up a storm with not much weakness in charge life.

If you stress them down to cutoff, you will probably need batteries months earlier than if you swap them out at 3.5v. It's the heat of charging from an almost dead state, coupled with the stress of vaping down to cutoff that kills batteries early.

 

[Moonbogg]

A question and a comment:

What was the source of the AW 18650 batteries? Unless purchased from an authorized AW dealer, they could be counterfeits and be an inferior battery.

If all are authentic AW batteries, the 18490 AW's have a 16.5 amp continuous discharge rating (15C). The 18650 2000 mAh AW's only have a 10 amp continuous rating. The higher amp rating of the 18490's could allow for less voltage drop because of their higher amp reserve.

My

All batteries purchased from Provape and all are new. I don't understand how the C rating would effect the voltage drop if the amp draw from the atty was fixed and under the limits of the batteries. I don't say it isn't happening, I just don't understand it why it would happen.

 

[DaveP]

All batteries purchased from Provape and all are new. I don't understand how the C rating would effect the voltage drop if the amp draw from the atty was fixed and under the limits of the batteries. I don't say it isn't happening, I just don't understand it why it would happen.

Batteries are designed to be able to carry a certain load for a given amount of time. The C-rating is an indication of how much internal heat they can withstand while under heavy load. The C-rating is a number that you multiply by the MAH rating to determine that load. If your C-rating is 10 and your battery is rated at 2000mah, then 10 * 2 = 20 amps continuous drain (2000mah = 2 amps). If that same MAH rated battery has a C rating of 20, then your continuous load capability would be 40 amps.

 

[Ryedan]

OK experiment in progress. Same voltage setting on Provari, same kayfun build. Yesterday when I put the fresh 18490 in, I checked voltage on provari under load and it said 4.1v. The 18490 lasted from 7am until midnight and only then started blinking about 3.2-3.3v/

Last night I put a fresh 18650 that had been fully charged and resting for well over a day. Fresh voltage reading under load on provari was 4.0v. I've only taken a few drags off it and already its down to 3.8 volts reading on provari. When I unscrew the kayfun, the voltage reading goes up to 4.1v. The voltage drop under load is greater for the 18650 with provari extension cap than with the 18490.

I'll use it until it blinks and see where I end up as far as run time goes. It seems the 18650's start off with more voltage drop under load and almost seems that they aren't even getting a full charge or something. It doesn't seem right for sure. I'm using that cheap charger from provape for $18.00.

Battery Charger for Electronic Cigarettes

EDIT: Um, ok. Something wrong here. This thing is already down to 3.7 Something isn't right at all. I've been vaping lightly and at this rate it will be dead by noon.

Here's a comparison of the AW 18650 2000 mAh and the AW 18490 1100 mAh. The bigger battery wins at all amp draws from 2A to 5A. You have not mentioned which 18650 you have, but this site doesn't list the 1600 mAh.

Here you can compare the AW 18650 2000 and 1600 mAh batts. They don't list the 18490. Just chose the two batteries from the drop down lists, clear the currents they have checked and check 5A. The 2000 mAh wins solidly down to 3.2V. At 10A the 1600 hits way harder than the 2000, but this is irrelevant with a Provari.

By looking back and forth a couple of times between the two charts at 5A, you can see the 18650 1500 definitely beats the 18490 1100 mAh also, but by less than the 2000 does.

IMO there is something wrong with your 18650s.

 

[Ryedan]

All batteries purchased from Provape and all are new. I don't understand how the C rating would effect the voltage drop if the amp draw from the atty was fixed and under the limits of the batteries. I don't say it isn't happening, I just don't understand it why it would happen.

I would get in touch with Provape and tell them the story. IMO you should get satisfaction from them.

 

[Ryedan]

OK experiment in progress. Same voltage setting on Provari, same kayfun build. Yesterday when I put the fresh 18490 in, I checked voltage on provari under load and it said 4.1v. The 18490 lasted from 7am until midnight and only then started blinking about 3.2-3.3v/

Last night I put a fresh 18650 that had been fully charged and resting for well over a day. Fresh voltage reading under load on provari was 4.0v. I've only taken a few drags off it and already its down to 3.8 volts reading on provari. When I unscrew the kayfun, the voltage reading goes up to 4.1v. The voltage drop under load is greater for the 18650 with provari extension cap than with the 18490.

I just realized you don't actually tell us what the battery voltages were immediately off the charger, before they go into a device. That would be good to know.

 

[Moonbogg]

I just realized you don't actually tell us what the battery voltages were immediately off the charger, before they go into a device. That would be good to know.

4.1-4.2

Also, that 18650 that was showing oddly low voltage, did last longer anyway than the 18490. It was midnight (the time the 18490 died) and that 18650 still had 3.5v and wasn't going to die any time soon. So it does last longer when directly compared in an apples to apples way, despite the voltage drops being different. They are the 2000mah 18650's. I'll come back to this issue later, but for now, thanks for the replies and help.

 

[DaveP]

My batteries come off the charger at 4.2v and drop to 4.1v with the first vape. That's about standard for li-ion/IMR chargers. It's the same with my old Trustfire TR-001 and my Nitecore Intellicharger I4. Sounds like you are good there.

Your increased life may just be due to the fact that you are vaping less frequently lately or hitting it a little less aggressively. When a battery is new, its internal resistance is lowest. Over its life internal resistance will rise and cause the battery to slowly discharge itself even when you aren't using it under load. If these batteries are brand new, the first few charge cycles may have conditioned the battery and brought all it's internals to full efficiency. That increase shouldn't be all that noticeable, IMO. I vote for more efficient vaping ... shorter hits and less frequent hits as being the reason you are getting more hours between charges.

Here's a good article on the care and feeding of the Li-ion and LiMn batteries that we use.

http://batteryuniversity.com/learn/article/the_high_power_lithium_ion

 

[Ryedan]

4.1-4.2

Also, that 18650 that was showing oddly low voltage, did last longer anyway than the 18490. It was midnight (the time the 18490 died) and that 18650 still had 3.5v and wasn't going to die any time soon. So it does last longer when directly compared in an apples to apples way, despite the voltage drops being different. They are the 2000mah 18650's. I'll come back to this issue later, but for now, thanks for the replies and help.

Good to hear that Moonbogg. Yes, there is still a lot of energy left in the 2000 mAh at 3.5V under load