How low do you go ??

3_gun

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Joined
Jun 27, 2021
Messages
210
Most of my lights have LVP built in as well as a battery level of some type. I don't really trust either very much but of the two it's the battery level I trust more. Even with that said I've tested batteries at different levels & found the level as indicated & my Fluke don't often agree. Of those two I'll take the Fluke every time.

Few of my lights are paired to a specific battery. If I'm going out & know I'll be gone for awhile I'll drop the lightly/slightly used battery from my EDC in a holder & install a full charged one. If I'm REALLY going to be out I may even back up that switch with a spare battery or carry a second light.

This causes me to end up with a few mostly or partly used batteries on my desk. The question becomes when do I really need to recharge? I've been using 3.0v & less gets charged, 3.1-3.8v gets put in a light for short, "around the house" kind of use & 3.9v + is put back in the ready to use case.

I don't want to get caught with a dead battery half way thru a day but I also don't want to run to low or recharge to often. I think these are pretty good points for the actions but I've been using 18650/21700 lights for less than a year now & am doing a bit of second guessing.

Thoughts
 

xxo

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Joined
Apr 30, 2015
Messages
2,389
I usually charge when they get below 3.6V. If I am not going to use them for a while I charge to 3.9V.
 

parang

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Dec 28, 2020
Messages
124
I am careless - I leave it to the LVP to tell me the time is up and I charge everything with the Auto setting with my Vapcell S4 Plus. Samsung 21700-40T is prevalent. But these are all mostly used at home, no big deal if/when they are getting depleted.
 

chip100t

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Joined
Apr 1, 2021
Messages
71
I charge little and often the lights I use regularly as I like to know I always have a fully charged light on me. What I do do though is not leave the torch charging once the light says it’s charged it gets unplugged. I never charge anything overnight for this reason.
 

Lynx_Arc

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Joined
Oct 1, 2004
Messages
10,759
Location
Tulsa,OK
As rechargeables these days can be topped off anytime so as to not leave you stranded in the dark I typically just estimate how much use I have on a battery and if I truly need more than half the capacity at the next outing or not and recharge it accordingly. I've been caught off guard a time or two that is why you have a backup light for sure and your back up light uses the same size batteries and lithium primaries if available etc.
 

gearhead1972

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Joined
Mar 12, 2011
Messages
166
Location
Kent, NY
I use my light everyday in the shop at work, looking at machinery, looking for parts in conex boxes. So i pretty much check my voltages every other day. I also carry a backup on me, and a few in the car, plus I keep a charger at work and extra batteries. 3.8 will get put on the charger.
 

Poppy

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CPF Supporter
Joined
Dec 20, 2012
Messages
6,023
Location
Northern New Jersey
I don't use lights for work, so compared to others, they get used infrequently. I know that for storage it is recommended that Li Ion be kept at 3.7 volts. Personally I don't bother reading voltages. I fill them up and periodically recharge the cells that are in some lights. When there is a hurricane coming, then I will grab 6-8 lights ,maybe more, and top off their cells, and usually my Ryobi 18V tool batteries. And top off 1/2 a dozen or so battery packs.

So I guess the short story is: I generally keep them near to fully charged. I don't care as much about losing some battery life/longevity, I want them fully charged and ready to go when I need them. I bought a charger that can determine the capacity of the battery. Some day, I'll read the directions, and actually use it. Then I'll toss the weak batteries, into a "Use when desperate" pile.

I have a back up pile of idk, 16-24 new, still in their boxes, (probably charged at 3.7 V) batteries that can be put into service at any time. So again, I don't have to be too concerned about losing a few mAh from batteries by keeping them topped off.
 
Last edited:

vicv

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Joined
Mar 22, 2013
Messages
1,330
Location
Southern Ontario
Most of my lights have LVP built in as well as a battery level of some type. I don't really trust either very much but of the two it's the battery level I trust more. Even with that said I've tested batteries at different levels & found the level as indicated & my Fluke don't often agree. Of those two I'll take the Fluke every time.

Few of my lights are paired to a specific battery. If I'm going out & know I'll be gone for awhile I'll drop the lightly/slightly used battery from my EDC in a holder & install a full charged one. If I'm REALLY going to be out I may even back up that switch with a spare battery or carry a second light.

This causes me to end up with a few mostly or partly used batteries on my desk. The question becomes when do I really need to recharge? I've been using 3.0v & less gets charged, 3.1-3.8v gets put in a light for short, "around the house" kind of use & 3.9v + is put back in the ready to use case.

I don't want to get caught with a dead battery half way thru a day but I also don't want to run to low or recharge to often. I think these are pretty good points for the actions but I've been using 18650/21700 lights for less than a year now & am doing a bit of second guessing.

Thoughts
3.0 volts is doing damage. 3.4v is dead. I like full brightness so I charge often. If I pull a cell out to check and it's at 3.8v or below, it/they get replaced with charged ones and they get put on the charger
 

Poppy

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Joined
Dec 20, 2012
Messages
6,023
Location
Northern New Jersey
I generally keep my cell phone at about 80%. It has rarely seen 100% and even less frequently has it seen less than 50%. It is usually between 60 and 87%. It seems to do well compared to my kids, but of course they use their more than I.
 
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