How to know when a battery is done?

[juicynoos]

QUESTION:

None of the batteries I first bought are more than 7 months old so I have no idea how or when they will show that they are in need of replacement.
They still hold 4.18v fully charged as when new and seem to have no significant drop when under load.

I'm wondering what will happen when they start to wain and need to know what to expect to see and how long before I should discontinue using an older cell.

Thanks for any info.

 

[AndriaD]

QUESTION:

None of the batteries I first bought are more than 7 months old so I have no idea how or when they will show that they are in need of replacement.
They still hold 4.18v fully charged as when new and seem to have no significant drop when under load.

I'm wondering what will happen when they start to wain and need to know what to expect to see and how long before I should discontinue using an older cell.

Thanks for any info.

As long as they don't do anything strange (one of my flat-tops, the flat-top got sorta dented, I think because I dropped the mod it was in), the main way is that they won't hold a charge as long. If you have a digital-readout on your charger, you might also note that they won't charge fully; a couple of mine only charge to 4.1, though it varies -- one day they'll only charge to 4.1, next day they might charge up fully to 4.2.

Andria

 

[juicynoos]

Thanks Andria, I have often wondered how they show their demise and never found anything posted here on the forum although I'm sure the question has been asked before since many have been vaping for yrs. My charger is a 4 bay Xtar with no digital readout but has many built-in features,,I'll read up on them again!

I use a multimeter to check each battery prior to charging when removed from a device. generally I use mechs but just got my first regulated 70 watt device and decided to use 2 new vtc 4's exclusively for that as it is a single 18650 device that makes high demands on the cells.

Sounds like pretty much the same story as with regular alkaline battery's then and no need to be especially aware of anything other than a gradual lessening of charging capability and longevity then.

 

[AndriaD]

Thanks Andria, I have often wondered how they show their demise and never found anything posted here on the forum although I'm sure the question has been asked before since many have been vaping for yrs. My charger is a 4 bay Xtar with no digital readout but has many built-in features,,I'll read up on them again!

I use a multimeter to check each battery prior to charging when removed from a device. generally I use mechs but just got my first regulated 70 watt device and decided to use 2 new vtc 4's exclusively for that as it is a single 18650 device that makes high demands on the cells.

Sounds like pretty much the same story as with regular alkaline battery's then and no need to be especially aware of anything other than a gradual lessening of charging capability and longevity then.

One tip I've read here, that I haven't seen about other batteries, is about "resting" them after charging; apparently it could be dangerous to take them straight from the charger into the mod for use. I don't know if the "resting" before charging is recommended, but I did that last night, since both the batteries I was using seemed a *bit* warmer than usual when I took them from the mods -- which might have been nothing but paranoia on my part, admittedly, but since one of those mods was a mech, I decided better safe than sorry, and I let them sit for a couple hours before putting them into the charger, and they were both fine.

I guess, considering how close to our faces we use these devices, "excessive paranoia" may be an oxymoron.

Andria

 

[Froth]

As long as they don't do anything strange (one of my flat-tops, the flat-top got sorta dented, I think because I dropped the mod it was in), the main way is that they won't hold a charge as long. If you have a digital-readout on your charger, you might also note that they won't charge fully; a couple of mine only charge to 4.1, though it varies -- one day they'll only charge to 4.1, next day they might charge up fully to 4.2.

Andria

This is pretty much how I do it, If a battery is starting to get aged I take note and while it's charging if it takes over an hour to go from 4.1 to 4.2 at 0.5a charge rate I generally remove it from my rotation, I have some VTC4's that have over 300 cycles on them that will not charge to over 4.0V any more, they're just sitting around waiting to be disposed of properly at this point.

 

[edyle]

QUESTION:

None of the batteries I first bought are more than 7 months old so I have no idea how or when they will show that they are in need of replacement.
They still hold 4.18v fully charged as when new and seem to have no significant drop when under load.

I'm wondering what will happen when they start to wain and need to know what to expect to see and how long before I should discontinue using an older cell.

Thanks for any info.

What I noticed on my vamo is the older batteries tend to drop fast in voltage then go back up in voltage over the next few seconds or minutes.
So if I chain vape on an old battery, it seems to go dead fast; but if I only take an occasional vape on an old battery, nothing seems wrong with it at all

 

[zoiDman]

QUESTION:

None of the batteries I first bought are more than 7 months old so I have no idea how or when they will show that they are in need of replacement.
They still hold 4.18v fully charged as when new and seem to have no significant drop when under load.

I'm wondering what will happen when they start to wain and need to know what to expect to see and how long before I should discontinue using an older cell.

Thanks for any info.

Most of the Time (I have found) when a Rechargeable Battery gets Old, it starts to Lose the Ability to Hold a Charge.

It might come off the Charger at a Peppy 4.18 Volts, but come back awhile later and the Voltage has Fallen Off some. And the Next day, it is Down More.

Shorter Battery Life while Using it is also a Sign that your Battery is wearing out.

 

[Racehorse]

A good charger, like a PILA, charges slow and safely, and doesn't trickle charge either. I always feel safe taking my batts off the PILA.

Of course, I don't stress my batts, either.

Old age, they just don't hold charge very long anymore, so off to recycling they go.

 

[Mangguo]

There are chargers that can measure the capacity of battery. If the capacity is below 70% of it when you buy the battery then you should probably replace it. Which means if the capacity is 2400mAh, and you can only charger 1600mAh into the battery, then the battery is not safe to use anymore. I personnally is very interested in chargers so I know there are chargers can do that. I may say a XTAR VC2, or their new VC4 charger.
The instructions says that discharge the battery to cut-off voltage (3.0V), then put it into a XTAR VC4 or VC2 charger, charging it with out time discontinuity, then you can know your real capacity of your batteries. Also, with this method, you will be able to know when you need to relace your battery.

Hope this helps.

 

[juicynoos]

There are chargers that can measure the capacity of battery. If the capacity is below 70% of it when you buy the battery then you should probably replace it. Which means if the capacity is 2400mAh, and you can only charger 1600mAh into the battery, then the battery is not safe to use anymore. I personnally is very interested in chargers so I know there are chargers can do that. I may say a XTAR VC2, or their new VC4 charger.
The instructions says that discharge the battery to cut-off voltage (3.0V), then put it into a XTAR VC4 or VC2 charger, charging it with out time discontinuity, then you can know your real capacity of your batteries. Also, with this method, you will be able to know when you need to relace your battery.

Hope this helps.

I have the Xtar VC4 and I can't find the instruction book that came with it anymore but I think the charger automatically discharges the battery prior to running it on charge cycle to maintain their condition..not sure. Thanks for the input

 

[juicynoos]

Thank you all for commenting. I pretty much knew what to expect but just wanted to get a clearer idea of things to watch out for. As you say Andria, there is always a niggle in the back of your mind about using failing components in proximity to one's face and I would prefer to stay on the side of safety, kind of like changing the tires on the car...they are all that is between you and the road

 

[jazon1]

you wouldn't want to discharge a lithium battery they have no memory issues,cycling one will just wear out faster,
that aside easiest way to tell a battery is on its way out is when it no longer lasts you as long as it once did ive had battery last me a full day new
and get to the point they were only lasting a few hours...thats around the time to recycle them and grab yourself some new ones,
alternately if you happen to have a provari 3 you can check the IQ of the battery using the menu anything under 60 is considered poor and below 30 is bad
this also checks the threads on the device as well for conductivity so make sure they are cleaned and lubed if your going to use one to check on your battery's health.

 

[juicynoos]

Hi Jazon, thank you for the information. I generally recharge my cell when they are at 50% or around 3.6-3.7 v since I only use them in mechs. I don't have a Provari or any other testing equipment other than a multimeter. It would be good if there were a device on the market for testing battery condition besides those built into mods or chargers. I guess I will have to upgrade my charger at some point.

cheers

 

[TaketheRedPill]

One tip I've read here, that I haven't seen about other batteries, is about "resting" them after charging; apparently it could be dangerous to take them straight from the charger into the mod for use. I don't know if the "resting" before charging is recommended, but I did that last night, since both the batteries I was using seemed a *bit* warmer than usual when I took them from the mods -- which might have been nothing but paranoia on my part, admittedly, but since one of those mods was a mech, I decided better safe than sorry, and I let them sit for a couple hours before putting them into the charger, and they were both fine.

I guess, considering how close to our faces we use these devices, "excessive paranoia" may be an oxymoron.

Andria

Hi Andria ECF'ers decided a loooong time ago that it was best to let batteries rest after coming off the charger. Here's the Library article authored by Rolygate :

http://www.e-cigarette-forum.com/forum/ecf-library/129569-rechargeable-batteries.html
'"
Rest batteries after charging
One commonly-reported factor in almost all the incidents we hear of where batteries failed violently while in use is that they were taken directly off the charger and then used immediately, at which point they failed.

Because of this, we think it may be a good idea to rest batteries after charging them. This advice will not be found in the usual 'reference bibles' on batteries, but we see more and different reports than others. Therefore we now advise:

Do not use batteries directly after charging them. Use a battery or batteries you previously charged, and that have rested for several hours. This is especially important if using a stacked pair for higher voltage, as statistically the risk is far higher."


also, from Battery University, I think the reason why is they're agitated from charging:
Recognizing Battery Capacity as the Missing Link – Battery University


"A battery requires few hours of rest to regain equilibrium..... Loads and charge currents distort the voltage further, but one of the largest challenges is the flat discharge voltage curve of some lithium-based systems. This is especially evident with lithium-iron phosphate."


So, it might be ok to take a battery off the charger to put in a flashlight or something like that, but where ecig type batts are concerned I've always let the batts rest.

Hope this helps

 

[DaveP]

Internal resistance builds over time and lowers the battery's ability to retain or deliver a charge. Rotating several batteries instead of one or two helps to lessen the daily stress and contributes to longer life.

I rotate 4 18650s in a 4 bay battery case. The last one in is the last one out as I rotate them to the bottom of the case. The most recently charged cell goes in the top space. That way, each battery gets a day or two rest between uses and after charging. I still have two AW 18650 2000mah batts that work fine after 3 years of use. I might get 5 hours instead of 6 out of an old one, but they still work.

 

[juicynoos]

Hi Dave, managed to kick that trekki habit yet bud? I use the exact same method as you, rotating 6 18650's, 4 of which I use in 2 mechs and 2 new vtc's that I use exclusively in my 70 watt regulated. In this fashion they all get rested sufficiently after charging. Those 3 year olds are doing well, I figure 2 would be good already. How many different devices are you using them in and are they mechs?

So I can measure the internal resistance of the cell with a meter and determine battery condition as resistance increases then?

 

[DaveP]

Hi Dave, managed to kick that trekki habit yet bud? I use the exact same method as you, rotating 6 18650's, 4 of which I use in 2 mechs and 2 new vtc's that I use exclusively in my 70 watt regulated. In this fashion they all get rested sufficiently after charging. Those 3 year olds are doing well, I figure 2 would be good already. How many different devices are you using them in and are they mechs?

So I can measure the internal resistance of the cell with a meter and determine battery condition as resistance increases then?

I'm currently at the end of season 6 Star Trek Next Generation on Amazon Video. Watching TV keeps me from getting bored on my daily stationary bike rides!

I've never felt the need to measure internal resistance on a battery. I just can them when the charge life drops below useful levels. Battery University is THE source for all things technical with batteries.

BU-902: How to Measure Internal Resistance – Battery University

Measuring the internal resistance is done by reading the voltage drop on a load current or by AC impedance. The results are in ohmic values. There is a notion that internal resistance is related to capacity, and this is false. The resistance of many batteries stays flat through most of the service life. Figure 1 shows the capacity fade and internal resistance of lithium-ion cells.

Troy Mikkelson wrote: (comment at bottom of article)

To Measure the internal resistance:
Buy a high wattage (10W) precision resistor of low value, say 0.1 ohm.

Put the resistor in series with the battery charger + cable and one terminal of resistor, connect battery charger - cable to battery -, connect second terminal of resistor to battery +, (A) Read the voltage across the resistor terminals. (B)Read the voltage across the battery terminals.

A) Divide the voltage across the resistor by the value of the resistor (0.1 ohms) to get the exact current flowing into the battery. This value will be used for step B

B) Divide the voltage across the battery terminals by the current found in step A. The answer will be roughly (a few percent, of a 70% accurate measurement is pretty good) the internal resistance of the battery.

Second Method: Get an ESR Meter (Equivalent Series Resistance) ($100-$300), these are essentially AC Ohmmeters with fixed or variable frequency. Measure resistance of battery (Equivalent Series Resistance) which is a direct reading with no other meters needed. These meters can be used on batteries from AAA to 9V alkaline with very good indication of health as well.

 

[juicynoos]

DaveP

"I've never felt the need to measure internal resistance on a battery. I just can them when the charge life drops below useful levels. Battery University is THE source for all things technical with batteries".

My artistic brain (non analytical sphere) just blew a fuse reading your quotes from the 'Battery University', so I will just chuck um when they become useless and be content However, I did get the gist of it and it put into perspective the answer to my original question so thanks for posting that.

Keep on trekking

 

[PaulBHC]

Hi Andria ECF'ers decided a loooong time ago that it was best to let batteries rest after coming off the charger. Here's the Library article authored by Rolygate :

http://www.e-cigarette-forum.com/forum/ecf-library/129569-rechargeable-batteries.html
'"
Rest batteries after charging
One commonly-reported factor in almost all the incidents we hear of where batteries failed violently while in use is that they were taken directly off the charger and then used immediately, at which point they failed.

Because of this, we think it may be a good idea to rest batteries after charging them. This advice will not be found in the usual 'reference bibles' on batteries, but we see more and different reports than others. Therefore we now advise:

Do not use batteries directly after charging them. Use a battery or batteries you previously charged, and that have rested for several hours. This is especially important if using a stacked pair for higher voltage, as statistically the risk is far higher."


also, from Battery University, I think the reason why is they're agitated from charging:
Recognizing Battery Capacity as the Missing Link – Battery University


"A battery requires few hours of rest to regain equilibrium..... Loads and charge currents distort the voltage further, but one of the largest challenges is the flat discharge voltage curve of some lithium-based systems. This is especially evident with lithium-iron phosphate."


So, it might be ok to take a battery off the charger to put in a flashlight or something like that, but where ecig type batts are concerned I've always let the batts rest.

Hope this helps

Just had a long discussion with the wife about this. We have MVPs and regulated tubes with IMR batteries.

Two things puzzle me about resting batteries.

What about passthrough devices like the MVP and what about these new box mods with usb charging of 18 series batteries in the mod?

Most people with either of these are likely to grab and go as soon and the charge has finished or even before.

 

[DaveP]

DaveP

"I've never felt the need to measure internal resistance on a battery. I just can them when the charge life drops below useful levels. Battery University is THE source for all things technical with batteries".

My artistic brain (non analytical sphere) just blew a fuse reading your quotes from the 'Battery University', so I will just chuck um when they become useless and be content However, I did get the gist of it and it put into perspective the answer to my original question so thanks for posting that.

Keep on trekking

The takeaway from all that info is in the chart. A good 1500mah battery typically drops to around 1200mah after 500 charges. That translates to 20% less vaping on a charge.