Battery ignorance….

[Buff]

Ok i have not ever been a rechargeable battery guy. So i bought several lights. Some came with batteries and i bought a spare. Then i bought more spares. I literally have a few to many spares. I store them in the thick ziplock plastic bag they came in. They all came at about 75% charged. Had no idea if the go below 2.5 there could be a problem? A fire hazard?? What to do? Do i fully charge them and then every 30-60 days repeat.
As i said i am totally ignorant to what to do and don't want to burn my house down.

This is my storage arrangement.

I did read a lengthy thread on batteries but an old one (2010) and a bit too technical. Just need storage idea as in fully charged then recharging on a schedule.

 

[KITROBASKIN]

Do not fully charge and let sit indefinitely.
Don't let batteries go down to nothing or low voltage disconnect and let them sit for long.
If considered backup, charge batteries to 3.8V-4V and enjoy life.
If long term storage, keep below 3.8V above 3.6V and enjoy life.
Check them semi annually (solstice or equinox?) and feel good about your due diligence.

Others will have some differences with this.

Batteries you want to be lower voltage, put them in a fun flashlight and maybe take them to the river walk in Morganton some lovely evening?

 

[Monocrom]

That's actually a good storage arrangement if one has tons of batteries. For anyone unaware "HART" is an in-house Wal-Mart brand mostly known for power-tools. (Most of which are very inexpensive but not very powerful at all.) As for the questions....

Not a fire hazard stored that way. But make sure the cells aren't touching each other end-to-end. As far as they stand still, and aren't used; they should be fine but check a few times a year. If a cell hasn't been used in quite awhile. Be sure to charge it up first before putting it in a light.

 

[Buff]

checking all my batteries now. I have two lights with Anduril 2 that has the test mode. All 18650 and 21700's were 3.6-4.2 so all is well there and I've had some for 4-6 months.

My smaller batteries are all showing 75% which is how they usually come with the lights.

Not sure what to do with this 4 pk still in the wrapping I purchased a month a go?

 

[Monocrom]

A month is nothing. No worries for now.

 

[Buff]

I was writing when y'all were responding in good time. I learn so much. Thanks.
Also if my charger says 75% is that 75% of 4.X or 75% of that usable range?

 

[iacchus]

Pick up a digital multi meter. It doesn't have to be a Fluke, just something you can use to check voltage to two places and not have to count the binks to do it. Solid investment, costs you a sawbuck.

 

[Buff]

Love this charger. It shuts off when battery is 100%. Definitely wouldn't mind a proper tester but maybe it's not necessary.
Plus i charge on the lowest setting. Guess that's ok?

 

[Buff]

@iacchus exactly what i was thinking.