My LiIon cells

[aLyr]

Hello to all of you,

we all have seen curves of discharges of LiIon cells.

But what happens if we want to charge them?
How long would this take and how would this compare to other cells?

So far, I can just report that a Sony VTC5A loads up to 4,2V at least 45 mins faster than a Sony VTC5 @ 500mA charge current.

Anyway, I have more results of my 14 LiIon cells, though I do not yet know too much about my matched pairs of Samsung 35E and Samsung 30Q. The first pair in my vaporesso Tarot Pro doesn't seem to be willing to lose capacity for several days already at a 18W load, far later than a box mod with a single cell. But I like it.

There's more to come.

Best regards,
aLyr

 

[Ben85]

I'm confused? Surely the capacity of the cell and the amount it's discharged determines how long it takes to charge?

 

[Jim_ MDP]

But what happens if we want to charge them?
How long would this take and how would this compare to other cells?

Not sure what answer you're looking for.

As a cell ages, or undergoes abuse, its' total capacity drops.
As we charge... the cycle starts easy, climbs to the set Amperage rate, then slows to a trickle at the very end to gently top off and finish the charging cycle.

Both of these will directly affect the time it takes to recharge a specific cell.

Now... if you have a charger that tracks how many mAh have been provided to the cell (some Xtars for example) and you want to experiment and carefully track it, you could get precise "charging time per capacity" measurements for each of your batteries.

Are you that bored?

 

[sofarsogood]

Hello to all of you,

we all have seen curves of discharges of LiIon cells.

But what happens if we want to charge them?
How long would this take and how would this compare to other cells?

So far, I can just report that a Sony VTC5A loads up to 4,2V at least 45 mins faster than a Sony VTC5 @ 500mA charge current.

Anyway, I have more results of my 14 LiIon cells, though I do not yet know too much about my matched pairs of Samsung 35E and Samsung 30Q. The first pair in my Vaporesso Tarot Pro doesn't seem to be willing to lose capacity for several days already at a 18W load, far later than a box mod with a single cell. But I like it.

There's more to come.

Best regards,
aLyr

I'm getting interested in the topic you raise. The advice to monitor how many mah it takes to charge the battery sounds like the way to go. Some chargers may have that built in but I have my eye on this device and will probably get one after christmas. May be some one knows of a better one they want to suggest.

https://www.amazon.com/dp/B00J3JSEG...lid=1175D1C0HPR2Y&coliid=I343IA33KNEHIV&psc=1

 

[Jim_ MDP]

I'm getting interested in the topic you raise. The advice to monitor how many mah it takes to charge the battery sounds like the way to go. Some chargers may have that built in but I have my eye on this device and will probably get one after christmas. May be some one knows of a better one they want to suggest.

https://www.amazon.com/dp/B00J3JSEG...lid=1175D1C0HPR2Y&coliid=I343IA33KNEHIV&psc=1

I threw one of those in-lines into an Amazon cart back when.
Used it to check the charge rate of my mods, mostly the old LiPo iSticks. Never used it much otherwise, but it works.

Keep in mind... it'll only work for in-mod charging and that rate isn't adjustable, but it will tell you the total mAh charge when it's finished.

Make of that what you will.

 

[sofarsogood]

I threw one of those in-lines into an Amazon cart back when.
Used it to check the charge rate of my mods, mostly the old LiPo iSticks. Never used it much otherwise, but it works.

Keep in mind... it'll only work for in-mod charging and that rate isn't adjustable, but it will tell you the total mAh charge when it's finished.

Make of that what you will.

Batteries lose their endurance over time from the stress of being both charged and discharged. Batteries like to discharged slowly and they like to be charged slowly. I'm not a fan of "fast" charging or discharging a battery at it's maximum amp rating. The mah meter should give a fairly accurate measure of the capacity of aging batteries and help to decide when to retire them. The meter in my link seems to have a lot of good reviews and there's no quibbling with the price.

 

[Jim_ MDP]

Batteries lose their endurance over time from the stress of being both charged and discharged. Batteries like to discharged slowly and they like to be charged slowly. I'm not a fan of "fast" charging or discharging a battery at it's maximum amp rating. The mah meter should give a fairly accurate measure of the capacity of aging batteries and help to decide when to retire them. The meter in my link seems to have a lot of good reviews and there's no quibbling with the price.

Major mfgr's spec the 18650 to charge at up to 4A.
I don't even use 2A with my 18650s... I don't have to worry about charging them too hard.

 

[aLyr]

I am well aware that cells of higher capacity take longer to be fully charged than those with lower capacity.
The thing is, that my VTC5s and VTC5As, having the same capacity of 2.6Ah, show a markly different charge time.

Please wait until I publish my graphs as to this.

Regards,
aLyr

 

[SteveS45]

I have always been under the impression that the best way to charge batteries is slowly. Trying to make comparisons between different cells is only relative to state of discharge or mAh as others have mentioned. Too many variables to consider.

 

[DaveP]

The Xtar VC4 or VC2 both show MAH as the battery charges. Of course, the MAH value you get at the end of charge depends on the charge level of the battery when charging begins. At any rate, a charger that displays MAH during charging can tell you something about the condition of the battery if you run them to a consistent state each time before charging.

 

[DaveP]

I have always been under the impression that the best way to charge batteries is slowly. Trying to make comparisons between different cells is only relative to state of discharge or mAh as others have mentioned. Too many variables to consider.

Slow is better because heat is a battery's enemy. Better charge density is probably achieved with a slow .5A charge than a 2A charge. I charge at 1A most of the time.

 

[Mooch]

Slow is better because heat is a battery's enemy. Better charge density is probably achieved with a slow .5A charge than a 2A charge. I charge at 1A most of the time.

There was about a 1.8% increase in capacity between cells charged at 0.5A vs 2A in my testing.

 

[DaveP]

There was about a 1.8% increase in capacity between cells charged at 0.5A vs 2A in my testing.

Would you say that the additional heat created by a 2A charge affects battery life over time? Do we pay the price for quick charges in repeated battery fatigue?

 

[Mooch]

Would you say that the additional heat created by a 2A charge affects battery life over time? Do we pay the price for quick charges in repeated battery fatigue?

Absolutely. Higher charge rates will always reduce cycle life. I find 1A to be a good compromise between convenience (charging speed) and cycle life. Anything below 0.375A-0.5A really doesn't make any difference.