How to Awaken Sleeping Li-ion

Li-ion batteries contain a protection circuit that shields the battery against abuse. This important safeguard has the disadvantage of turning the battery off if over-discharged, and storing a discharged battery for any length of time can do this. The self-discharge during storage gradually lowers the voltage of a battery that is already discharged; the protection circuit will eventually cut off between 2.20 and 2.90V/cell.

Some battery chargers and analyzers, including those made by Cadex, feature a wake-up feature or “boost” to reactivate and charge batteries that have fallen asleep. Without this feature, a charger would render these batteries as unserviceable and the packs would be discarded. The boost feature applies a small charge current to first activate the protection circuit and then commence with a normal charge.

 Do not boost lithium-based batteries back to life that have dwelled below 1.5V/cell for a week or longer. Copper shunts may have formed inside the cells that can lead to a partial or total electrical short. When recharging, such a cell might become unstable, causing excessive heat or showing other anomalies. The “boost” function by Cadex halts the charge if the voltage does not rise normally.

Sleep mode of a lithium-ion battery

 

Figure 1: Sleep mode of a lithium-ion battery

Some over-discharged batteries can be “boosted” to life again. Discard pack if the voltage does not rise to a normal level within a minute while on boost.

A study done by Cadex to examine failed batteries reveals that three out of ten batteries are removed from service due to over-discharge. Furthermore, 90 percent of returned batteries have no fault or can easily be serviced. Lack of test devices at the customer service level is in part to blame for the high exchange rate. Refurbishing batteries saves money and protects the environment.

Comments

On April 19, 2011 at 1:25pm
fhhuber wrote:

Note that some low voltage cutoffs are programmed for a SET voltage, others are based on RELATIVE voltage.

A set voltage cut-off would turn off power at the same voltage regardless of charge state when the battery was plugged in.

A relative voltage cut-off “detects” the battery voltage at plug-in and then the cut-off is a percentage of that voltage.

Because many hobbyist Radio Control system ESCs (Electronic Speed Controllers) use the RELATIVE voltage, it is imperative that a battery used in these applications be FULLY charged when it is plugged in.  A partially charged battery being plugged in can result in the cutoff being low enough to damage the battery.

On February 14, 2012 at 12:47pm
tytower wrote:

I had such a battery Hit it with a 40V pulse for 500 nsecs and it came good immediately

On April 3, 2012 at 7:59am
guy00 wrote:

I’ve tried to charge a battery that was not used for a year, but when i stopped using it it had a partial charge… now i measured it with a multimeter and it showed 0v (the protection kicked in). But when measuring between the negative and positive terminal AND the middle terminal (cell phone battery), it showed 1.09 and 1.04, respectively. I thought the battery is @ 2.13v, and tried to recharge it directly from the cell phone charger (red wire to the positive and black to the negative). A spark flied, but i continued to charge for another minute. Then i took a multimeter, measured, and it showed 3.2v smile. Then i continued to apply charging for another 2mins and got the battery up to 3.48v. Currently left the battery like that, it lits up a white LED very bright. I’m wondering is that battery safe for using now, i dont really need that battery, but if its working fine maybe i’ll find use for it since the cell phone i got it from is dead smile

On April 22, 2012 at 3:36am
Brian wrote:

Too involved and way off the topic.  How do I prolong lithiom ion battery life? :/

On June 25, 2012 at 10:44am
jake wrote:

What no one has said here is that Lion Batteries are prone to explode…Just see youtube.

Be very careful while resurrecting batteries always work under a perspex sheet with gloves., You can do almost any batteries..

On July 16, 2012 at 10:11pm
krist0ph3r wrote:

can i boost a cellphone battery using the regular charger, or do i need some special equipment to do so? would 5V/1A be enough?

On December 13, 2012 at 11:47am
Mad Monty wrote:

If Li ion batteries become unpredictably dangerous if left discharged too long, it would seem that no “found” batteries (e.g., old laptop unused for a “long time”) would be safe to use.  Have I got that right?  And following up, how best to dispose of them?

On January 11, 2013 at 2:37am
fred hreyer wrote:

How do you estimate when a lithium battery is at 40%?

On January 29, 2013 at 1:10pm
AbdEl-Rahman wrote:

That’s actually very great what you guys are writing , but actually needs some simplification on what should be done to boost it again on duty ,ya know.
So my request is for you guys to offer me a solution (SAFE Of course) to do to my iPhone Li-ion polymer battery ,that also doesn’t include removing it out of the phone .
I would be very grateful to have an expert opinion ,because I am done with those videos that never give a solution straight to a person,ya know .
Thank you for your time all

On April 5, 2013 at 11:32am
sam wrote:

guys can you please help me to restore my fully discharge li ion battery on my laptop,its about 5 months later after i bought it,i frequently using ac connection so the battery i’ve only used it ones a week,,but now its already fully discharge and i don’t how to awaken it..i already put it on my laptop but it;s not charging anymore,,,


thanks

On April 13, 2013 at 2:26am
Oscar Ormond wrote:

Take a technology that is very very difficult to get right then after spending hundreds of millions of dollars on research and it still not very good, knowing people want to use it simply go ahead and put it on the market. Take the money and run. Simple explenation.

On April 13, 2013 at 2:10pm
Mad Monty wrote:

So you want simple instructions on bringing a Li-ion back to life?  Here it is:  Choose either (1) to buy an expensive smart charger (like Cadex, above - no , I don’t have any stake in the company); or (2) Replace the battery.  That’s it.

Only those who can tolerate a brief explanation should read further. 

The reason not to try to fool with it yourself is that it really can go up in your face.  Literally.  Lithium-ion chemistry is not only more dangerous but also more complicated than NiH.  All the stuff you don’t want to read or try to understand is exactly the stuff in need to do to prevent a serious accident.  A smart charger figures it all out for you so you don’t get burned or blinded or destroy your laptop or whatever.  If you try to do it yourself, you have to think through all the algorithms, make complicated measurements, and administer the charge, all the while continuing to monitor and measure and make adjustments until either the battery reaches its maximum charge or you determine it is beyond hope.  (Ever look inside a laptop battery?  There is a whole slew of sensors and circuitry attached to each cell, whose primary requirement is to prevent harm and lawsuits.)

Yes, some people – many people – have been lucky when they have tried to rejuvenate batteries in simple ways.  If they played Russian roulette, five out of six would think that was pretty safe too.

Madly yours,

Mad Monty

On May 4, 2013 at 5:21pm
Parker Thornton wrote:

Any Batteries Plus or Batteries Plus Bulbs can recycle them for you. Please don’t throw them away.
They also have a Cadex and a laptop battery reconditioner and can restore batteries for you if you ask, usually for free

On May 21, 2013 at 2:57am
carribawhore wrote:

If you have an old camera li ion cell charger, like canon. You can easily bring dead batteries back to live. Without danger. Just connect the + and ~ of the charger with wires directly on the poles of the li ion akku. Then insert an empty camera battery in the charger and there you go.

On June 20, 2013 at 2:47pm
Mike wrote:

to AbdEl-Rahman: unfortunately you would have to take to battery out of your iphone, you need to jump start the li-ion battery with a high voltage at a low amperage which in turn would fry the circuits on you phone, there are tons of walkthroughs on how to remove and replace iphone batteries online, its not that difficult especially if you document where each screw goes and how you took it apart piece by piece.

MAC/Windows professional with 10+ years tech experience

On June 28, 2013 at 12:36pm
Sean M wrote:

“How do you estimate when a lithium battery is at 40%?”

As a rough example, if your battery pack normally lasts, say 10 hours under continuous use, you’ll reach 40% of usable capacity after six hours.

If all you go on is variables, you won’t know.  the simplest is to use the above method.

On July 10, 2013 at 2:52am
s.pirie wrote:

my wife has been using e cigarettes for three months now using ego t brand who give no back up for faults , these use lithium ion batteries , the fault is no operation of the atomiser although the battery voltage shows around 3.8 which is what is expected although the 3.8v is showing at the battery without pressing the operating button which you would expect this to make the atomiser work constantly with no need to press the button, this does not happen . Does anyone have any idea how i can fix this fault ? My wife is in desperation as all of her 5 batteries faulted on the same day which is very curious .

On July 20, 2013 at 2:52am
emmit wrote:

The batteries you have for the e-cig have a turn on / off sequence 5 pushes in 3 seconds or less will turn the device on (push on/ push off non latched)...and the same will turn the battery off..the battery also has a fail safe It will auto shut off if the button is depressed for more than 10 seconds (could be 7/8/9 seconds depends on battery type eg.ego

On September 24, 2013 at 12:26am
Yu Jun Gu wrote:

Just brought two efest 14500 protected batteries back to life. Thank you for this article!! They must have been in storage for a very long time, got them from a friend who didn’t want them anymore. Was having a helluva time. Charger didn’t register them. The way I woke them up was sticking them into a AA battery box I had laying around and connecting an 18650 (Positive to positive negative to negative) to the lead wires for 30 seconds or less. Freaked me out the first time around because the 14500 got real hot and I thought I had thermal runaway on my hands. But it cooled off again and when I checked the voltage it was at 3.07v. Repeated that step with the second battery just much shorter duration of charge with the 18650 this time around, like 10-15 seconds. Woke it right up. In the charger now recognized and charging as usual.

On September 25, 2013 at 3:18pm
mark wrote:

Does anyone have a working battery for a schwinn Transit bicycle i can buy?

On November 6, 2013 at 7:24am
Rodelion wrote:

Often I get frozen cells (showing 0V) to work again by putting it in a universal li-ion charger several times. Universal li-ion chargers give all kinds of pulses to the cell to figure out what kind of voltage and polarity the cell has. I think those pulses make the battery work again.

On another instance, with a Nikon EN-EL5, this didn’t work…
After a lot of effort I found out there are two hidden contacts underneath a little seal, so five in total. Through trial-and-error I found out that the hidden contact next to the ‘+’ corresponds with the positive terminal, and the one next to the ground, corresponds with the negative terminal. I think there’s a condenser between these two contacts, and I used a 6V lithium battery to charge it. When I got at about 3.7V, the battery suddenly started working again.
While doing this, both batteries became warm, but not quite hot. If a cell becomes really hot, I think you’re on dangerous ground.

On November 23, 2013 at 10:08pm
David wrote:

I have a weird issue with a protected 14500 battery. The battery shows 3.4v and will lit up a small LED (not a Cree or high output LED), but will not take input charge by the charger (charger light green like if it was not charging instead of orange) and when trying to boost it up using another 4.2v 14500 battery connecting + and - together, like mentioned above, it doesn’t seem to work at all, i.e. the defective 14500 won’t accept any input. It has about 200ma left out of ~600mh max capacity and will not power up my Cree P4 LED flashlight at all while the other 14500 battery will (even a 1.2NiMh battery doesn’t have problem powering this light).

Now I’m thinking the protection circuit might be defective and locked itself up whenever I try to input voltage/current or draw too much current out of it. Would there be anyway to save this battery by either resetting/bypassing the protection or simply physically removing the protection PCB ? It’s a brand new battery fresh from the store, and although they’re sending me a replacement one anyway, I’d hate to waste a salvageable product.

Thanks !

On December 17, 2013 at 7:31am
RKSINGH wrote:

BETTERY OF DIGITAL CAMERA(DCR-DVD610 ) HAS FULLY DISCHARGED. PL CONFIRM, HOW TO CHARGE.

On December 29, 2013 at 4:18pm
johny wrote:

according to what i’ve read, you can revive a dead li-ion with a low-current trickle charger. if the battery does not spring past 2.5 volts within one minute of trickle-charging, then the battery should be discarded. even if keeping on the trickle longer than one minute revives it!

is because the battery chemistry changes after it’s discharged and unused too long, making it dangerous to revive or use.

if it takes longer than one minute to revive, then the battery is dangerous, and should be discarded.

how to revive:
http://youtu.be/CCQU8eW3TGk

i don’t understand what this guy is doing:
http://youtu.be/xyeHKKe2z0Q

On January 24, 2014 at 10:09am
jach wrote:

read again what mad monty wrote above. wise words. lithium chemistry is POTENT, experimenting with advice provided in a forum without understanding the basics of what your dealing with isnt recommended.and is literally russian roulette ,attempting to duplicate what worked in someone elses case , may explode in your face

On February 6, 2014 at 4:34pm
Sailor Jo wrote:

Very enlightening article. Still, I need to do some more research in order to understand the intricacies between the various types of lithium batteries.
The reading made me aware of the charger PIXO C4. I thought I found the ultimate charger until I checked the German manufacturers web site and the batteries that cannot be charged with this unit. A real eye opener, especially as it cannot charge the 18650 batteries that I have a problem with. Just too bad.

On March 4, 2014 at 9:43am
Emil wrote:

I just waked to life two 18650 batteries that came from a dead laptop battery I opened, the battery had 8 cells, four was complete dead, two was good and two had around 2V.
I used a iMax B6 charger and used NiMH charging with 0.1A current limit, charged the battery untill it shown 3.2V and then swopped over to lithium charging.
I put a iron pot over the battery lying on my concrete floor in the garage while I charged, in case the battery was blowing up or starting to burn.

On March 28, 2014 at 12:32am
e2cc_guru wrote:

I have designed a system which uses a 7.4 V, 6,6AH Li-Ion battery pack (18650) in the configuration 2S-3P. It is charged using a uC based software algorithm which is CC till 8.4V and then CV till current falls below 0.05C. I charge the battery using a 12V DC charger or a 12 V Solar Panel. Obviously there is a bick-converter in between which manages the voltage applied to the battery.

Recently I am getting field complaints that batteries which go to sleep would not revive using the software charger.

Can any one suggest what is wrong or what I should try? Please ask if you need more information.

On September 1, 2014 at 11:37pm
Paolo wrote:

Can I try to awaken a li-po battery from a Thinkpad notebook?
The Thinkpad don’t charge it.