Li-Ion Batteries - THE TRUTH

[batexp]

One other tid-bit that everyone should be aware of with regard to LI batteries is the storage time and effect.

As many here are stockpiling product in the event of a FDA ban, there are some downsides to stockpiling LI batteries.

If stored at room temp LI cells discharge by 20% and loose capacity at the same rate within a year.

As such it is expectable that the voltage will eventually drop below the automated cut out limit over time.

Once this happens your regular charger will not work to recharge your battery.

Kinda stupid if you ask me, to put a low voltage cut out limit to protect the battery if a normal charger will not work to recharge the batter once this occurs thereby rendering the battery useless to its' owner.

Oh well I guess that's to help sell more batteries, but I digress.

As mentioned in the OP, the manufacturers ship LI batteries with a partial (50% or so) charge, therefore, if you buy a bunch of batteries and intend to store them for long periods of time it would be wise to charge them full to prevent the voltage from falling below this cut out voltage.

Naturally even storing fully charged has drawbacks as the full charged battery will degrade at a faster rate as far as loss of capacity.

In order to reduce this degradation it is recommended that LI batteries be stored at 32 degrees.

It would also be wise to recharge your spare batteries periodically.

This will both reduce the voltage loss and the degradation rate.

 

[scyllabub]

Is that 32 degrees Fahrenheit or Centrigrade/Celsius?

Many thanks,

scylla

 

[jongleur]

Is that 32 degrees Fahrenheit or Centrigrade/Celsius?

Many thanks,

scylla

I wondered the same thing the first moment I read that, but 32C would be about 90F, which doesn't seem too likely a recommended battery storage temperature! Therefore, I assume he means 32 degrees Fahrenheit.

--John

 

[Wings]

Wow. Just found this thread and read thru it. Allow me to add my 2 cents' worth. I'm an electronics engineer and have designed Li-Ion and Li-Poly chargers (good ones).

About the charger cutoff: I cannot conceive of anyone (cheap Chinese mfg included) designing a Li charger that did NOT terminate the charge at the appropriate time, since a continuous trickle charge will most definitely kill the battery you are attempting to charge.

The red/green status light on the charger: I'm certain that red means it's charging, but green could mean one of two things. First, a word about the charge process... A Li is initially charged at some value of constant current (typically .5xC to 1xC, where C=AmpHour rating of battery) until the cell voltage reaches 4.2v. A properly designed charger (and all Li charger chips I've seen) then switches over to a constant voltage of 4.2v until the current drops to some low value (typically .05xC to .1xC). Then the cell is completely disconnected from the charger circuit. The charger may or may not instigate a new charge cycle if the battery voltage drops while the battery is left in the charger. Usually if the cell is being used continuously while also being charged (such as in a cell phone, or laptop), the recharge cycle is repeated at 4.0 or 4.1v, something like that. The green light on our chargers may come on when the charger switches from constant current to constant voltage, where the cell is about 80% charged, OR it may come on when the charge is completely terminated. These are the two events during the charge process where it may make sense to inform the user of the charging status. Which event to use depends on the designer's purpose. If he/she wanted you to know that there is adequate charge in the battery for it to be useful then turning on at 80% charge would make some sense. If they wanted you to know that it was 100% charged then they would turn it on at 100%, when it is disconnected. We won't really know the answer to that question until the company that designed it speaks up (not likely) or until someone cuts open a battery tube and makes some measurements. So... green may mean it's almost charged or it may mean it's completely charged. (Glad I could clear that up for ya.)

Note that making a measurement for battery charge current may be inconclusive if you measured it between the charger terminals and the battery tube. The reason for this is that there is some electronics inside the battery tube that could be drawing some unknown amount of current while connected to the charger. Not only that, but the electronics inside the battery tube may even be where the smarts are that control the charging. The only way to know for sure would be to cut open the battery tube and make the measurement at the terminal leading right into the battery.

Also, I read somewhere in this thread about Li batteries wearing themselves out over a period of just a few years even if not used. Don't know where this came from. It's news to me, and quite contrary to all my learnin' and experience. I'm sure they will go bad EVENTUALLY but I don't think it's anything a nicotine addict like me is going to worry about. I'll wear mine out by using it long before they will rot on a shelf.

Also, I have an issue with the statement that shallow discharges equates to longer battery life. I say, not to any degree that we will be able to detect without instrumentation. It is true that a very deep discharge will have an impact on life, but these batteries are designed to be used from their fully charged 4.2 volts down to 2.5 or 2.7 volts, where automatic disconnect takes place. Don't worry about it. Puff until it blinks, then replace it with a charged one. (I'm assuming your battery blinks its LED as it disconnects due to low voltage.)

....and all I meant to do this morning was to order some more e-liquid, and you folks have distracted me for hours. I think I'll be ordering a 30ml bottle of Totally Wicked menthol. Sure beats the price I was paying - $15 for 10ml from electroniccigarettesinc.com. And I think I may experiment with some various flavors this time. I've only been at this "vaping" thing for a month, and haven't had an old timey cigarette since then!

Say, has anyone tried T-Wicked's Screwdriver thing? I sure like the battery life, and I could manage the size. But that button, on the END? I'm having a hard time imagining that that would be anything other than awkward.

 

[scyllabub]

I can't read all that properly, I go into suspended animation But it's nice to have another member with expertise.

Puff until it blinks, then replace it with a charged one. (I'm assuming your battery blinks its LED as it disconnects due to low voltage.)

I don't get blinking warnings because I use (1) a Screwdriver, and (2) a USB passthru. (BUT see below before you buy anything else!)

I've only been at this "vaping" thing for a month, and haven't had an old timey cigarette since then!

Well done you

Say, has anyone tried T-Wicked's Screwdriver thing? I sure like the battery life, and I could manage the size. But that button, on the END? I'm having a hard time imagining that that would be anything other than awkward.

(1) SD button - surprisingly, not awkward, though at first I thought it was - I use the inside of my pinkie (the side next to the ring finger, not the palm side). The button is quite wide and flat on the end so it doesn't cause irritation or "injury".

(2) Check out this small-time (no offence, Garry, I'm bigging you up here ) modder's site. If you're not in a rush you can save more than a few bob:

https://www.epayments.co.uk/epages/es120919.sf/secBVwH4TTlqGg/?ObjectPath=/Shops/es120919_shop

From the Categories menu on the left, check out USB Passthrough and Torch Mods.

By the way - am I wasting my time looking for 5v batteries? Do they not exist?

scylla

 

[Wings]

I took apart my 510 USB Charger device so I could get to the lead going to the charging tip. I put a digital ammeter in series with it. Unfortunately my meter injected too much resistance into the battery circuit and caused the charger to behave differently. Charging this way, the LED started off red then gradually changed color to nearly all green as the charge completed. Usually what I see is solid red until charged then flashing between red & green. It started off with a constant 113 ma for the first 45 minutes, then an abrupt change to 42ma, then a gradual decrease down to 13ma over the next 2 hours. From then on every few seconds it would alternate between 90% green and 10% red to 100% green. Now here's the important stuff:
* While it was 100% green there was zero charge current.
* While it was not solid green there was current going to the battery.
* It remained like this for several hours, until I terminated the test.

My conclusion is that this is a very very bad charger. Once it goes green and charge current is zero, it soon snaps back to charge again. This semi-continuous charge current will kill a Li battery. The only way I would use this is if I was going to be there the entire time I was charging and could remove the battery at the first sign of a green flash. And now, this makes me wonder what my USB Passthru device is doing to its little battery. It has no LED.

(It appears that whatever electronics is inside the battery tube, it is not drawing any current from the charger and has not interfered with this measurement. My next test will be to open up my wall charger and test it too. Maybe. It's glued together and not screwed like the USB charger. I'll have to think about that.)

 

[batexp]

yes, that's 32 degrees Fahrenheit

 

[magnetitis]

Hi all! I've got a problem with my batteries. They seem to have stopped working, despite using various atomisers and cartridges in combination with the batteries. I don't really have any basis to complain about the batteries having stopped working, considering the way I've treated them, but I was wondering if there was any way I could restore them?
To put the problem in context, the kind of batteries I've got have an LED at the end to indicate both inhalation and charging. When I try to charge my batteries, this LED flashes as it should, and the battery takes a length of time to charge before it stops flashing (to indicate a complete charge). Yet, when I try to use the battery it doesn't respond to my inhales. They worked before, but seem to have stopped. I would put this down to me having ruined the batteries, but they seem to charge as if they still work (if that makes sense...) Is there some way that batteries may stop working on a superficial level but remain restorable? If it helps, I bought these batteries from best-ecig and the problem may stem from water exposure-I charged them in the bathroom unfortunately. Any help would be most appreciated.

 

[scyllabub]

When I try to charge my batteries, this LED flashes as it should, and the battery takes a length of time to charge before it stops flashing (to indicate a complete charge).

What is the exact model e-cig you are using? I have never known an e-cig battery that keeps flashing while it is being charged But maybe I've led too sheltered a life

The very fact that the LED keeps flashing would indicate to me that a battery is duff.

scylla

 

[magnetitis]

Thanks for replying scyllabub! For some reason one of my batteries has started working again which is a bit of a mystery. The model ecig I'm using is the mini e-cig 401 from best e-cig. I realise maybe Chinese ecigs don't have the best reputation for quality but I'm pretty sure this is my fault (don't charge your batteries in the bathroom while you're having a shower!)

Basically the issue was that the batteries stopped working when used in an ecig but they acted as they did when they were working if they were charged. So it's like they've partially stopped working but as batteries they still work on some level (if this makes any sense, I'm really bad at explaining things). I was basically wondering if anyone's seen something like this before. When I said it kept flashing I sort of meant it flashes 3 times when you plug it in, then flashes again when it's finished. This took some time to happen so clearly the charger was doing something to the battery.

 

[scyllabub]

I think that's the model that I know as the Evo. I wonder if you might find help amongst this lot of threads:

M-401/402 "Mini" & M403 Super Mini - E-Cigarette Forum

You might find info about similar experiences just reading it through.

Also, the site you bought it from might have their own forum where you're sure to "meet" fellow owners.

I'd be pulling my hair out (and maybe even smoking 8-o ) if I were you. Good luck, magnetitis

scylla

 

[Doublexl85]

YES!!!! I knew it, everyone gave me crap for charging lithium batts over night. I WINS haha

 

[NatureBoy]

good post, thanks OP

 

[Pegasus7]

Thanks All for posting....
Good info.

 

[Mr. Mom]

Great post. I use lithium polymer batteries to fly my rc airplanes and this indeed the truth. 3.7 volts is the nominal voltage for a single cell. Fully charged is 4.20. Don't discharge below nominal voltage and store them at about 3.85 volts. A lithium battery works best if you recharge them when they show the slightest signs of low performance.

 

[tsmith35]

Be careful when storing lithium batteries. If shorted, they can explode. If you keep one in your pocket, make sure nothing else metal is in that pocket. Learned this from experience with flashlights.

 

[Quick1]

Wow. Just found this thread and read thru it. Allow me to add my 2 cents' worth. I'm an electronics engineer and have designed Li-Ion and Li-Poly chargers (good ones).

Excellent post. Thanks.

I have a question about discharge rates. Is there a "rated" discharge rate for Li-Ions? Some max rate?

Normal 510 atomizer runs about 2.2 ohms. Is the discharge rate within reason? or only for short bursts. Sustained?

Even more interested in those used for operating an atomizer at 6v. 2 3v Li-Ions (CR2s for example). What's the discharge rate there? Within reason?

 

[Wings]

Excellent post. Thanks.

I have a question about discharge rates. Is there a "rated" discharge rate for Li-Ions? Some max rate?

Normal 510 atomizer runs about 2.2 ohms. Is the discharge rate within reason? or only for short bursts. Sustained?

Even more interested in those used for operating an atomizer at 6v. 2 3v Li-Ions (CR2s for example). What's the discharge rate there? Within reason?

All batteries have a recommended maximum discharge rate specified by the manufacturer so I can't make a flat statement about the discharge rate of all Li-Ion and Li-Poly batteries. For continuous use it's typically around the same as its rated capacity, and often more. For intermittent pulsed discharge, this rate is several times the rated capacity of the battery. Typically an 800mahr Li-Ion rechargeable CR2 can safely be loaded to 2.5A and higher for short periods. I wouldn't hesitate to load one to even twice that as long as I make sure it isn't on long enough to overheat the battery. As a rule of thumb if the battery is uncomfortable to hold, it's getting too hot.

As for your 2 CR2s driving a 2.2 ohm atomizer (3.3 amps), I'd do it and wouldn't worry about it.

 

[V4P3_V1CT1M]

Thanks for the good info! I just purchased an ScrewDriver and the mkII battery has been charging for over 6 hours and still isn't done charging. Can anyone tell me if something is wrong with it?

Thanks in advance,
Brett

 

[Quick1]

Thanks for the good info! I just purchased an ScrewDriver and the mkII battery has been charging for over 6 hours and still isn't done charging. Can anyone tell me if something is wrong with it?

Thanks in advance,
Brett

I'd say yes, there is something wrong with something.

Look at the mAh on the battery. Look at the mA output of the charger. Divide the mAh on the battery by the mA charger output. That's about how many hours it would take to charge a drained battery.

The capacity rating on the battery is listed as the current draw that will drain a fully charged battery in 1 hour. It pretty much works in reverse when you're charging it. (and you generally don't want to fully recharge a drained battery in less than an hour).

1) could be that it's done charging and there's something wrong with the led on the charger.
2) could be the charger is broken.
3) could be the battery is bad (the battery should not get more than warm even when charging at the max rate). Pretty much max rate charge is 1 hr.