Lets say you want to try to revive that cell, you charge it at low current, reach those safe 3V and then charge it at, lets say, 0.5C to 4.2V. You try it in a flashlight and it works well. You discharge it to 3V and charge it again, without problems. Is it safe to use from now on?
NO! Once the cell voltage falls below the safe threshold, the chemistry inside can go wonky. If recharged, then at any time in the future the cell can spontaneously flame. The main cause is the growth of crystals/metal spikes that can pierce the separator membrane causing the cell to short circuit.
FOR THE LAST TIME FOLKS… NEVER ATEMPT TO REVIVE OR REUSE A LOW VOLTAGE CELL! GET IT THROUGH YOUR THICK HEADS AND KEEP IT THERE! NEVER!
Hehe, ok ok, boss :bigsmile: Thanks 
Hi,
Is “wonky” a highly technical term :)??
JUST KIDDING :)!!
Jim
This for all lithium chemistries.
BTW, Sony doesn’t make Li-cobalt cells. That post was referring to their chemistry (basically IMR that could be revived from 1.5V) ) to standard Li-cobalt cells (where 2.5V is the usual deadness threshold).
If you have low voltage cells, a recommended disposal method is to toss them in a bucket of salt water overnight to fully discharge them and then take them to a proper disposal/recycling center.
If you do not believe Sony, then try Panasonic. They do not put a voltage on, but it is somewhere below 2.3 volt in their LiIon Handbook.
Others are correct. Do not use the battery. Li-ion cells discharged that low can form sharp crystals in the catalyst which rip through the thin bag that holds the catalyst. When the bag is ripped, all bets are off. Time for the famous “vent with flames.”
Since you do not have an xray machine to see inside the battery, you can never know when and if those crystals form. Venting with flames can happen at any time. Tomorrow or a year from now.
Also remember that venting with flames is a THERMAL non-electrical condition that can take adjacent cells with the venting cell. Pretty soon you won’t just have one cell venting but 10 or 20 (if you store your batteries near each other), and that’s more than enough to burn down your house or catch your car on fire.
They didn’t just ground an entire fleet of planes because li-ion fires are not really a problem. They grounded the planes because li-ion venting cells are VERY dangerous.
And did I mention all the toxic gases that a venting cell produces?
And reviving a low-voltage cell saves how much money? Just not worth the risk.
Hi All,
Ok, ok, I GOT IT already :)!
And, the battery is back to the vendor, and he should receive it today, according to USPS tracking.
I’m glad that I asked the question, and the answer, in general, was very clear, so I appreciate that.
Thanks,
Jim