3 ms·

>To be clear, it isn't the cell dropping below 2.5V that will cause the cell to turn into a bomb, it is afterwards attempting to recharge it that is dangerous.S

>To be clear, it isn't the cell dropping below 2.5V that will cause the cell to turn into a bomb, it is afterwards attempting to recharge it that is dangerous.Stop using and never charge a Li-ion cell that's voltage dropped too low. >Do not store Li-ion cells long term at full capacity, but instead at 3.7V. These are great suggestions, and also they are absolutely impossible to follow given that we have absolutely no access to the sealed Li-Ion cells in devices that we buy. How would the OP even know what voltage the cells inside his headphones are at? Even with replaceable cells, we can't expect people to have the tools to measure the voltage - unless the device itself displays it. And even then, if we know that charging a cell after its voltage drops below 2.5V is dangerous, why do we allow chargers that do that (including devices with internal batteries) to be sold to the public?

Maursault 5y ago
With experience one can have an idea of what charge is left on a cell. One easy way to gain experience is with a decent Li-ion flashlight. It doesn't take a whole lot of tools to test resting voltage of a cell, a cheap multimeter will do. Modern chargers should be smart, have some function to automatically test for resistance, and refuse to charge a cell with resistance that is too high or if voltage under load is below 2.5V. Frankly, I am a bit astounded these devices were developed. I'd recommend against wearing Li-ion cells on your head unless you really know the cells, know their age and history.
- romwell 5y ago
  Again, as a tinkerer, I'm happily learning from your comments — thank you! But the general public can't be expected to know all that without it being even in the booklet that comes with the product. >Frankly, I am a bit astounded these devices were developed. Well look at the comments here that say "risk of death is a part of life, deal with it". That kind of attitude is why.

Maursault 5y ago

With experience one can have an idea of what charge is left on a cell. One easy way to gain experience is with a decent Li-ion flashlight. It doesn't take a whole lot of tools to test resting voltage of a cell, a cheap multimeter will do. Modern chargers should be smart, have some function to automatically test for resistance, and refuse to charge a cell with resistance that is too high or if voltage under load is below 2.5V. Frankly, I am a bit astounded these devices were developed. I'd recommend against wearing Li-ion cells on your head unless you really know the cells, know their age and history.

romwell 5y ago
Again, as a tinkerer, I'm happily learning from your comments — thank you! But the general public can't be expected to know all that without it being even in the booklet that comes with the product. >Frankly, I am a bit astounded these devices were developed. Well look at the comments here that say "risk of death is a part of life, deal with it". That kind of attitude is why.