Battery Life Span?

[Petrus]

Hi Guys.

The batteries I am rotating on a daily basis consist of 18500/18650. I 90% of the time only do mechanical mods. My vape preferences is between 0.30-0.60 ohm. How to I know/or can determine when it is time to replace batteries?

Any feedback of the 18650/18500 AWT "yellow" batteries?

Thank You.

 

[zadiac]

I try to keep track of my charging cycles, but it's difficult. I keep batteries for a year or until I notice the performance drop or it discharges faster than normal. Then I know it's time to replace.

 

[Silver]

Hi @Petrus
You are asking a great question

Battery manufacturers usually say how many cycles their batteries are good for before they need to be replaced. I have seen 300 and 500 cycles being used for this lifespan measure. I believe when they get old they dont hold their charge as well and their capacity usually declines.

I suppose the only way to test them properly is to test them on proper testing equipment that costs a small fortune. I am also interested in knowing what telltale signs vapers can look out for without being able to properly test a battery.

As far as I know, an older battery wont easily charge up to 4.2V and wont hold its charge there as long. But that doesnt really apply to me. My older Efests sit at 4.20 for quite a few days whereas my much newer Samsung smurfs drop to about 4.17 after a week or so.

My purple 18650 Efest "Reo fleet" have been going for about 18 months or so. I have 8 of them and rotate them evenly. I probably use about 2-3 batts per day. Lets take 3 to be conservative. 18 months is 540 days. So thats 1,620 "cycles". Shared between 8 batts, thats about 200 each so cycle-wise i assume its still ok. 2 batts per day would tranlate to about 135 cycles. So i would estimate my batts have had 135-200 cycles each. They still seem ok to me but maybe its just my perception - i sometimes think they are not performing like they did. Maybe its just my own vaping development seeking more power and "kick".

Another thing is how much one stresses the battery. Mine have spent most of their time powering higher ohm builds at lower power in the 0.8 to 1 ohm range. I have only recently gone quite a bit lower in ohms. So the number of cycles I suppose needs to be qualified further according to the stress experienced in those cycles.

Maybe @johan or @Gazzacpt can comment and offer some ideas and advice - or anyone else who has observed their batteries closely in this regard.

Very interesting topic indeed

 

[Spydro]

Agree, interesting topic @Silver. But one that has never concerned me much. I have something like 70-80 batteries for vaping, they are marked and rotated "most of the time". My usage is high enough vaping 24/7/365 most of the time with up to 10-12 mods that the 18650. 18490 and 14500 have been mostly used soon after they are recharged (the 18350's not used for a long time, but will still take a full charge). With up to 9 charging at the same time all the time round the clock, I'm good.

 

[Christos]

A way to tell is to see how much charge in mah the battery is taking.
E.g if the battery is a 1000 mah battery and you are discharging to let's say 3.5v you should only be putting back say 300mah.

If the battery takes over 1000 mah charge then it's time to replace.
Charges like the xtar vc4 have this capability and I have asked vendors to bring it in but so far only the vp4 has been available.
Voltage is not a true representation of what the battery chemistry is doing.

I have a few batteries that are over 2 years old that I still use. The voltage is down to 4.16 on a full charge but they perform and last a good 6ml so I'm still using them.

The above method for replacing batteries is for remote controll heli batteries and understandably you would be gutted seeing a R30 000 aircraft falling out the sky because a battery failed or rather you failed to notice a failing battery.

 

[johan]

@Silver you will immediately know when any of you're batteries are "moeg" (near end of life). I personally measure internal resistance/impedance of battery when its new (note on battery with marker pen). [In my humble opinion its the most important spec of any battery, and more so for the vaper that wants close pairs]. As soon as I experience too much of a voltage drop and/or can't satisfyingly vape half a Reo bottle of juice from fully charged, I measure internal resistance/impedance again. If the latter shows a significant increase, I bin same and replace. Will try a photo post in the next week or so how I confirm manufacturer's spec on capacity (mAh) as well as internal resistance test on a small self build battery tester - no need to be exorbitantly expensive.

PS. A few tell tales of battery near-end-of-life:

• Experience significant voltage drop
• Doesn't hold charge like it used to (need to be recharged quicker)
• Get warmer than usual when in use and/or charged
• Doesn't charge higher than +/-3.15V
• Loose charge over a 36h or quicker period without being used.

 

[Silver]

Thanks @johan !
Much appreciated
Very useful