How low do you go ??

3_gun

Enlightened
Joined
Jun 27, 2021
Messages
213
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

Flashlight Enthusiast
Joined
Apr 30, 2015
Messages
2,409
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

Newly Enlightened
Joined
Dec 28, 2020
Messages
125
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

Newly Enlightened
Joined
Apr 1, 2021
Messages
81
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

Flashaholic
Joined
Oct 1, 2004
Messages
10,773
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

Newly Enlightened
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

Flashaholic
CPF Supporter
Joined
Dec 20, 2012
Messages
6,048
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

Flashlight Enthusiast
Joined
Mar 22, 2013
Messages
1,353
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

Flashaholic
CPF Supporter
Joined
Dec 20, 2012
Messages
6,048
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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