Li-Ion Batteries - THE TRUTH

[Magnus]

Hi everyone,

Sorry for the long post but this is the kind of stuff you need to know!

I have just stumbled across the definitive guide to Lithium Ion batteries, which details exactly how to look after your e-cig batteries in the best way to preserve good charge and long life.

It also dispels a few of the myths surrounding battery care and charging.

The first link I am quoting from is written by a gentleman who has been working with and researching rechargeable batteries for 20 years!! This guy definitely know his stuff! All credit to Mr Isidor Buchmann, the founder and CEO of Cadex Electronics Inc., in Vancouver BC.

Amongst the most interesting a relevant points he makes are these -

1. Li-Ion cells do not benefit from a longer initial charge:

" Lithium-ion is a very clean system and does not need priming as nickel-based batteries do. The 1st charge is no different to the 5th or the 50th charge. Stickers instructing to charge the battery for 8 hours or more for the first time may be a leftover from the nickel battery days."

"Unlike nickel and lead-based batteries, a new lithium-ion pack does not need cycling through charging and discharging. Priming will make little difference because the maximum capacity of lithium-ion is available right from the beginning. Neither does a full discharge improve the capacity of a faded pack."

2. Leaving the cells in the charger for any longer than necessary for a complete charge (usually around 3 hours) will not improve the battery's performance or capacity:

"Most cells are charged to 4.20 volts with a tolerance of +/?0.05V/cell. The charge time of most chargers is about 3 hours. Smaller batteries used for cell phones can be charged at 1C; the larger 18650 cell used for laptops should be charged at 0.8C or less. The charge efficiency is 99.9% and the battery remains cool during charge. Full charge is attained after the voltage threshold has been reached and the current has dropped to 3% of the rated current or has leveled off."

Once fully charged:

"No trickle charge is applied because lithium-ion is unable to absorb overcharge. A continuous trickle charge above 4.05V/cell would causes plating of metallic lithium that could lead to instabilities and compromise safety. Instead, a brief topping charge is provided to compensate for the small self-discharge the battery and its protective circuit consume. Depending on the battery, a topping charge may be repeated once every 20 days. Typically, the charge kicks in when the open terminal voltage drops to 4.05V/cell and turns off at a high 4.20V/cell. "

3. Leaving the cells in the charger for any longer than necessary for a complete charge (usually around 3 hours) will probably reduce their life-span:

"Hints to long battery life-

• Limit the time at which the battery stays at 4.20/cell. Prolonged high voltage promotes corrosion, especially at elevated temperatures. (Spinel is less sensitive to high voltage than cobalt-based systems).

• 3.92V/cell is the best upper voltage threshold for cobalt-based lithium-ion. Charging batteries to this voltage level has been shown to double cycle life. Lithium-ion systems for defense applications make use of the lower voltage threshold. The negative is reduced capacity"

"Much attention is focused to avoid over-charging and over-discharging. Commercial lithium ion packs contain a protection circuits that limit the charge voltage to 4.30V/cell, 0.10 volts higher than the voltage threshold of the charger."

4. Over-discharge of the cell is far more damaging but protected against by the equipment, in our case the e-cig when it cuts out:

"Extreme low voltage must also be prevented. The safety circuit is designed to cut off the current path if the battery is inadvertently discharged below 2.50V/cell. At this voltage, most circuits render the battery unserviceable and a recharge on a regular charger is not possible.
There are several safeguards to prevent excessive discharge. The equipment protects the battery by cutting off when the cell reaches 2.7 to 3.0V/cell. Battery manufacturers ship the batteries with a 40% charge to allow some self-discharge during storage."

5. He also confirms that there is NO MEMORY EFFECT, so top up charges are no problem, but that eventually the cells will die nonetheless:

"Best of all, there is no memory but aging issues are the drawback.
"

Please take a look at the page, and at least we can all be sure that we are getting the most out of the batteries and not doing anything wrong. It eliminates one variable when we are trying to work out what is going wrong too...

I can't post links yet, since I have not made the obligatory 15 posts, but rather than post a load of fake posts to lift the limit - go to the site `batteryuniversity` with the usual ww's and com's and it's all in Part1 Section BU12.

Many thanks to Mr Buchmann.

The second link, taken from wisegeek.com confirms all the above info but in a less scientifically stated manner, eg:

"Unlike its predecessor, the nickel-cadmium, lithium-ion batteries do not suffer from the "memory effect." That is, the battery does not have to be fully discharged before being recharged. On the other hand, earlier nickel-cadmium batteries would "remember" where they were recharged, leading them to charge only to that point again. Later developed nickel-metal-hydride batteries also solved this problem.
Though the batteries do not suffer from the memory effect, it is just the opposite that users should be wary of. Lithium ion batteries shouldn't be run all the way down before charging; they respond much better with constant recharges."


"Eventually all rechargeable lithium ion batteries will meet their end. After about two to three years, li-ion batteries expire, whether or not they are being used. To prolong the battery when not in use, store it in a cool dry place at approximately 40 percent capacity. Also, avoid exposing a lithium ion battery to extreme temperatures for prolonged periods of time, and recharge constantly when in use."

Once again I can't post the link, but go to the site and run a quick search and you'll find it.

Anyway, I for one am relieved to finally know what should and should not be done with a Lithium Ion battery cell, used in all e-cig devices as far as I am aware, especially considering the amount of nonsense you hear about the benefits and necessity of long charges and complete discharges.


I can't post this in the Tech or Tips areas since I am a new member to the Forum, but any full members who could do so please feel free since this would be useful to novice and experienced vapers alike, who might not read the New Members posts very often. You would also be able to post the direct links and share this information more easily.


Hope this has been useful.

[asidrave]

thanks for posting this Magnus...ive said in many posts its not necessary to charge the batteries for 6, 10 or 12 hours...even for the first time..

once the charger light turns green...its done...no more charging needed...period. of course there may be some exceptions...such as a battery that may be at the end of its life

ive have never had a problem with the battery being undercharged...my 6 batteries last consistently for 3 to 4 hours...depending on how much i vape.

i dont think it matters which battery from which manufacturer...i have both a DSE 801 and DSE 901..i charge them the same...once the light is green..its done

that goes for any Li-Ion and Li-Po battery

[Programmer]

once the light is green..its done

that goes for any Li-Ion and Li-Po battery

I did snip the majority of your post, but the idea is preserved: You're saying it doesn't charge at _all_ once the light turns green.

Can I ask what information you base that conclusion on?

[asidrave]

i used to race R/C cars in 1/8 and 1/10 scale onroad indoors and outdoors about 3 years ago for close to 6 years on an amateur level.

I used 1.2v 3000 to 3600 Li-Ion mah batteries in 4 and 6 packs. batteries were charged to peak before use and then quick charged just before practice or a race. good batteries were always consistent.

the cars gearing was tuned for maximum performance for a 5 minute race. i tuned and fine tuned gearing so that the batteries would last 5 minutes and 20 seconds... give or take 10 seconds. granted each battery cell was matched...thats a different story.

if you want to know more...ask away

[asidrave]

in specifics to the DSE 901 charger i have...here are the charging specs i took off the back of the charger.

Output: 4.2v 0.1A = 100ma

the 901 battery is approximatly 180 to 200MaH

so in charging...it should take 2 hours...give or take some minutes and if also the charger specs are correct and the battery charger correctly detects the peak charge of the battery.

im not saying that i am 100% correct...if anyone knows something i dont know...please post

[Programmer]

Ok, got it. Since you charge a lot of batteries you _know_ that the current flow into the battery is stopped once the light turns green on this Chinese charger. Even though this is a completely different charger and completely different battery than you're used to. Not that you put a meter on the battery and charger you ARE used to, in the first place.

Nope, that's good enough for me.

'Bout as good as voodoo, thanks,

[wv2win]

[quote=asidrave;137030]thanks for posting this Magnus...ive said in many posts its not necessary to charge the batteries for 6, 10 or 12 hours...even for the first time..

ive have never had a problem with the battery being undercharged...my 6 batteries last consistently for 3 to 4 hours...depending on how much i vape.

asidave, from your experience with batteries in general, should the ouput (effectiveness) of our e-cig batteries be the same for the first 30 minutes after being fully charged as the last 30 minutes before they need to be recharged? Or as they are depleted to say 30% are they less effective?

[asidrave]

[quote=wv2win;137165]

thanks for posting this Magnus...ive said in many posts its not necessary to charge the batteries for 6, 10 or 12 hours...even for the first time..

ive have never had a problem with the battery being undercharged...my 6 batteries last consistently for 3 to 4 hours...depending on how much i vape.

asidave, from your experience with batteries in general, should the ouput (effectiveness) of our e-cig batteries be the same for the first 30 minutes after being fully charged as the last 30 minutes before they need to be recharged? Or as they are depleted to say 30% are they less effective?

good question...ive noticed that the performance is greater during the first few drags on the e-cig. that is mostly because the battery is charged at its peak and hold is for some time....it will slowly discharge and go flat....even when removed from charging and letiing it sit.

the same principal applied when i raced r/c cars...the first few minutes the car would be a bullet...then the speed would go flat...then suddenly die out.

example...if the battery peak high voltage is 4.2..it will hold that for a short time..then it will flatten out at 3.7...then it will stay at 3.7...then quickly discharge to the cutoff at..i believe 2.5. that is why the first drags out of a freshly charged battery is greater and then stays consistant the more we drag with the battery....then falls to the cutoff

again..if not correct...please post i surely do not want to mislead anyone. this is all from personal experience and what ive learned from others

[BadAxe]

Ok, got it. Since you charge a lot of batteries you _know_ that the current flow into the battery is stopped once the light turns green on this Chinese charger. Even though this is a completely different charger and completely different battery than you're used to. Not that you put a meter on the battery and charger you ARE used to, in the first place.

Nope, that's good enough for me.

'Bout as good as voodoo, thanks,

Wow, what a contribution to the site. So helpful.

Bout as helpful as a PC helpdesk. Thanks.

[Magnus]

What you're saying sounds quite right Asidrave. Besides, anybody who wants to know more or is does not want to take my word for it, which I fully understand, should go the the batteryuniversity website.

There is far more information there than I have included in my first post anyway, and the guy writing is the definitive authority on all kind of batteries.

Go take a look for yourselves!

This thread was supposed to settle disagreements about batteries, not start arguments!

LOL!