Hello,
Recently i had to change the battery in my cell phone because it was bulging and this got me thinking.
I learned a long time ago that charging an Li-ion cell such as an 18650 to only 4.15v instead of 4.20 volts leads to longer life, and charging up to only 4.10v leads to even longer life.
Now 4.10v amounts to roughly 87.5 percent capacity which is almost 90 percent. The life expectancy could go up by a lot though, at least 2 times longer possibly even more. That's not bad considering we only lose 10 percent capacity.
Also, most people keep an eye on their percentage anyway so if it gets too low they charge it again.
Even losing 20 percent would not be too bad (about 4.05v max) if we dont need the full run time of the phone before the next charge can be done. A charge to 80 percent could lead to four times the life expectancy.
It's kind of funny i never applied this idea to my phone. I guess I was always worried that if i really needed it i didnt want the battery to run down before i was done using it. In a power outage (we had one the other day due to a fire in town) you really want your phone to have a good run time. So the trade off is longer battery life vs emergency or unexpectedly long run time.
But thinking this through, i then have to wonder what would be a good minimum percentage before the next charge. Previously i was charging constantly and if i was out or something and it went down to even 85 percent i would quickly charge it back up again to 100 percent. So i was doing the worst possible. Electrical stress is often measured in terms of voltage and/or current so the more voltage the more stress. 100 percent is worse than 90 percent and 80 percent is less stress than either.
So if charging to only say 80 percent, what would be a good minimum. I hate to go too low like 20 percent.
What do you think? How are you charging your phone and what minimum do you allow before charging again?
Recently i had to change the battery in my cell phone because it was bulging and this got me thinking.
I learned a long time ago that charging an Li-ion cell such as an 18650 to only 4.15v instead of 4.20 volts leads to longer life, and charging up to only 4.10v leads to even longer life.
Now 4.10v amounts to roughly 87.5 percent capacity which is almost 90 percent. The life expectancy could go up by a lot though, at least 2 times longer possibly even more. That's not bad considering we only lose 10 percent capacity.
Also, most people keep an eye on their percentage anyway so if it gets too low they charge it again.
Even losing 20 percent would not be too bad (about 4.05v max) if we dont need the full run time of the phone before the next charge can be done. A charge to 80 percent could lead to four times the life expectancy.
It's kind of funny i never applied this idea to my phone. I guess I was always worried that if i really needed it i didnt want the battery to run down before i was done using it. In a power outage (we had one the other day due to a fire in town) you really want your phone to have a good run time. So the trade off is longer battery life vs emergency or unexpectedly long run time.
But thinking this through, i then have to wonder what would be a good minimum percentage before the next charge. Previously i was charging constantly and if i was out or something and it went down to even 85 percent i would quickly charge it back up again to 100 percent. So i was doing the worst possible. Electrical stress is often measured in terms of voltage and/or current so the more voltage the more stress. 100 percent is worse than 90 percent and 80 percent is less stress than either.
So if charging to only say 80 percent, what would be a good minimum. I hate to go too low like 20 percent.
What do you think? How are you charging your phone and what minimum do you allow before charging again?