How often should I check li-ion voltage?

withoutink · 2019-10-21T13:14:00.000Z

Since I work full time from home, I don’t use my flashlights a ton. That being said a number of my lights just sit dormant ready and waiting to be used. How often should I check the voltage on batteries that aren’t used very often (either in lights or in my battery storage box), I was thinking of simply adding a calendar reminder to prod me as needed.

TIA

Unheard · 2019-10-21T14:15:12.000Z

At least once a year, preferably on Dec., 21st. More seriously, there are flashlights that drain their cell faster than that, and sometimes protected/charger equipped cells drain themselfs due to a defect or design flaw. Or both.

I fear, to be on the safe side, you have to test your equippment.

Couchmaster · 2019-10-21T15:05:52.000Z

Depends on the flashlight. I’ve taken to unscrewing tailcaps on ones that are not in the mix. However, 18650 batteries by themselves sitting for 6 months lose very little voltage.

flydiver · 2019-10-21T15:09:35.000Z

Yep, depends on the light AND the battery.
Some lights have a parasitic draw and will pull down the voltage over time. Those can often be disabled by unscrewing the back a bit and breaking contact.
Old batteries will self discharge faster than newer batteries. Really old batteries may show their ‘character’ by losing even faster.

I put a piece of painters tape, the kind that you can put on for a LONG time and still remove, on the light, note the battery, voltage, and date. I found some bright green stuff that works well for this. The blue is hard to read. I seldom charge over 4.0v for lights that are going to sit for a long time. For stored batteries I take them to ~3.7v and store them in the fridge.

All batteries get checked at least once a year. The batteries in service is more like 3-6 months.

withoutink · 2019-10-22T22:24:29.000Z

Awesome thanks so much, I was just thinking about putting in a calendar event for every 3 months. So that sounds safe enough. Thanks again

Obviously I will keep an eye on in-use batteries more frequently

Lightbringer · 2019-10-22T23:08:29.000Z

Idle cells, I generally just ignore them.

I’m not planning on keeping them in “active status” or anything. If a new batch that gets fully-charged when I test them on arrival holds their voltage well enough a year later, they’re good to go. If I plan to use them in a light, I just top ’em off.

Inside lights, though, I always physically lock ’em out, tailswitch or sideswitch, no different.

d_t_a · 2019-10-23T12:28:09.000Z

flydiver:

Yep, depends on the light AND the battery.
Some lights have a parasitic draw and will pull down the voltage over time. Those can often be disabled by unscrewing the back a bit and breaking contact.
Old batteries will self discharge faster than newer batteries. Really old batteries may show their ‘character’ by losing even faster.

I put a piece of painters tape, the kind that you can put on for a LONG time and still remove, on the light, note the battery, voltage, and date. I found some bright green stuff that works well for this. The blue is hard to read. I seldom charge over 4.0v for lights that are going to sit for a long time. For stored batteries I take them to ~3.7v and store them in the fridge.

All batteries get checked at least once a year. The batteries in service is more like 3-6 months.

Store batteries in the fridge?