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 [FONT=Verdana, Arial, Helvetica, sans-serif]Isidor Buchmann, the founder and CEO of Cadex Electronics Inc., in Vancouver BC.[/FONT]
Amongst the most interesting a relevant points he makes are these -
1. Li-Ion cells do not benefit from a longer initial charge:
" [FONT=Verdana, Arial, Helvetica, sans-serif]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."
"[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]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. [/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]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:
"[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]Most cells are charged to 4.20 volts with a tolerance of +/?0.05V/cell. [/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]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."[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]
Once fully charged:
"[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]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. "[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]
[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]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:
"[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]Hints to long battery life-[/FONT]
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:
"[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]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."[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]
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:
"[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]Best of all, there is no memory but aging issues are the drawback.
"[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]
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[/FONT] 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.
[FONT=Verdana, Arial, Helvetica, sans-serif]
[/FONT]
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 [FONT=Verdana, Arial, Helvetica, sans-serif]Isidor Buchmann, the founder and CEO of Cadex Electronics Inc., in Vancouver BC.[/FONT]
Amongst the most interesting a relevant points he makes are these -
1. Li-Ion cells do not benefit from a longer initial charge:
" [FONT=Verdana, Arial, Helvetica, sans-serif]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."
"[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]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. [/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]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:
"[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]Most cells are charged to 4.20 volts with a tolerance of +/?0.05V/cell. [/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]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."[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]
Once fully charged:
"[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]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. "[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]
[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]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:
"[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]Hints to long battery life-[/FONT]
- [FONT=Verdana, Arial, Helvetica, sans-serif]
[*] 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).[/FONT]
- [FONT=Verdana, Arial, Helvetica, sans-serif][FONT=Verdana, Arial, Helvetica, sans-serif]
[*]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"[/FONT][/FONT]
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:
"[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]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."[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]
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:
"[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]Best of all, there is no memory but aging issues are the drawback.
"[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]
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[/FONT] 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.
[FONT=Verdana, Arial, Helvetica, sans-serif]
[/FONT]