Use vs Abuse what is acceptable battery practice?

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how crazy is this
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Use vs Abuse what is acceptable battery practice?

Clearly there are many ways to damage a lion cell and trash it or make it dangerous. Assume we all try to avoid the truly bad (extreme temps, low / high voltage, physical damage etc). I have a few things I do for which I think the benefits outweigh the risks. However I am curious, just where is the cost benefit ratio?

Thinking of this as I just got a pair of earbuds that I really like. The charging case fits in my pocket and is very convenient to store them in. Fairly safe assumption that it does terminate properly and not over charge. Much less certain what happens at say 90% charge. Will it just terminate or will it always go for that last 10%. Should I even care? They were $40 and if I get a couple of years or so out of them that would be as good as I typically get before something breaks anyway. Would always having them fully charged – even if that is frequently after a very small amount of use really shorten their life that much?

I charge my phone nearly every night when I go to bed. This is supposed to be bad but I have been doing it for years and especially with the last two phones I have had I just don’t see enough degradation to make up for the convenience.

I keep my 18650s fully charged. I don’t have all that many in the first place and most of them are in lights so when one gets low I want a full battery ready to go. Not worth the hassle to me to do the right thing and simply top off before using. How much am I really loosing on this? Doesn’t seem worth it to me. Have some very old Tinnergy cells that still perform over 80 or 90 percent of new and they have always been stored fully charged. So far the only cells I have had that have degraded quickly were just junk cells in the first place.

Anyone wipe out earbuds much quicker than expected because you always kept them in the charging case and were using them throughout the day as well? Don’t most of us maintain at least a limited amount of cells fully charged an ready to go anyway?

If I knew that I would say keep my current 5 – 6 hours of play time for like a year longer if I didn’t put them in the case until they were down at least a 4th or half it may be worth the effort. Could it be just as likely that just putting them in the case all the time would only cost a few minutes of play time or a few weeks faster wear? Thoughts?

pennzy
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My cheap Vipon deal earbuds drain the charge case battery when left unattended for months. I now remove them until I’m going to use them. Just something to check for.

D'AVerk
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about 3-5-8% capacity lost per year if stored charged in cool place, and 5-15% if in hot.
About 1-3% if store in cool place charged up to 40%.

I store new and reserver cells in door of refrigirator charged up to 3.5V and have operational pool charged full for immediate use.

We should remember, that main problem for modern flashlight is not datasheet capacity on 0.2C, but inner resistance and ability to hold high currents. Very possible situation, when hicrrent cell still have 90% on 0.2C, but can’t hold anymore any currents close for C+

flydiver
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Sounds like you already answered your own question. Acceptable is anything that doesn’t cause fire or harm. You seem fine there.
After that it’s just a matter of hassle vs longevity.
Best practice is more hassle than ‘whatever is easy for you’, and may not be ‘best use…..for you’.

To Air is Human, to Respire….Divine.

D'AVerk
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flydiver wrote:

After that it’s just a matter of hassle vs longevity.

As for me, i d’t see any hassle in saving part of cells in storage condition.
Especially, if in operational state about 5-8 cells. Time to warm and charge cells is pretty little. Anyway, a can’t use more then 5-6 flashlights in one time Big Smile
flydiver
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I use the same practice. 90% of my can cells are in cold storage.
My EV Nissan Leaf sits mostly at 30-50% and I seldom charge it over 80% unless needed. When THAT battery starts losing too much capacity it’s an expensive predicament.
My phone gets mostly 30-70% charge use, unless more is required.

To Air is Human, to Respire….Divine.

Perception
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Outside of being unsafe, you just have to figure out how much battery degradation is ok with you. I have EDC lights that I top off almost daily, so they probably spend their entire life above 4V. I do it because I’m not carrying an extra battery in my pocket and I want all the runtime I can get if I need it. My at home lights are different though. I pull those batteries off the charger around 4V, and then use them down to probably 3.2-3.4 before I charge. I can always grab another battery or light at home, so I keep those batteries in the middle of their range to keep them happy and extend their life. All in all though, I’m not very tough on batteries so I don’t notice the effects of degradation very much anyway.