18650 Battery charging question

[MrWarspite]

I know you dont want to drain a battery all the way down if you can avoid it. When i fully charge my 18650 i get 4.1v on the lavatube display.

How low do these go for being drained?

Id like to try and recharge at 50%.

Cheers!

 

[RocketRod]

I wouldn't discharge it below 3.2v But i'm sure others have opinions. there are allot of systems out there that will stop the use of one at that voltage. Not sure if the lavatube has that type of protection.

 

[sailorman]

I have a Lavatube (V-Tube). The battery is 1600mah. I chain vape for about 6 or 7 hours and recharge at 3.8V.

The Lavatube is supposed to start blinking at you at 3.3V, but I've never seen it.
The battery shouldn't be run down below about 2.8 volts in any case.
I have heard the LT has a cutoff somewhere below 3.3V, but I've never gotten there either.
Some people claim it cuts off and some claim it doesn't, but I wouldn't depend on it in any case.

I recharge at 3.8V, but I think a good compromise would be 3.5V. That ought to get you an easy 8 or 9 hours on a 1600mah battery. If you have a 2000mah, you could probably go 12 hours before 3.5V.

BTW, after a few charges, your battery should charge to 4.2V

If you want a super long lasting battery, get a 2250mah Panasonic CGR18650CH for $10 shipped from Orbtronic.com
It's superior to the AW batteries in every way. See the Lavatube forum for more details.

 

[newq]

If memory serves the LT simply shutsdown at 3.0v on a LT with 18650 batteries preventing overdrain. I would take rocket rods suggest as the lowest just to be safe. if you take 4.1 - 3.2 Thats a .9 volt swing .45v at 50% battery life would set the device listing the batteryvoltage at 3.7-3.6 volts as discharged 50% of usable capacity. HOWEVER. If you actually consider that these are 3.7 volt batteries and we are overcharging them to 4.1 just inside the safety shelf of the battery you would only really be discharging the batery by .1 volts from it rated max capacity.

Food for thought.

 

[newq]

I have a Lavatube (V-Tube). The battery is 1600mah. I chain vape for about 6 or 7 hours and recharge at 3.8V.

The Lavatube is supposed to start blinking at you at 3.3V, but I've never seen it.
The battery shouldn't be run down below about 2.8 volts in any case.
I have heard the LT has a cutoff somewhere below 3.3V, but I've never gotten there either.
Some people claim it cuts off and some claim it doesn't, but I wouldn't depend on it in any case.

I recharge at 3.8V, but I think a good compromise would be 3.5V. That ought to get you an easy 8 or 9 hours on a 1600mah battery. If you have a 2000mah, you could probably go 12 hours before 3.5V.

BTW, after a few charges, your battery should charge to 4.2V

If you want a super long lasting battery, get a 2250mah Panasonic CGR18650CH for $10 shipped from Orbtronic.com
It's superior to the AW batteries in every way. See the Lavatube forum for more details.

Oh no. we meet again.

 

[MrWarspite]

I have a Lavatube (V-Tube). The battery is 1600mah. I chain vape for about 6 or 7 hours and recharge at 3.8V.

The Lavatube is supposed to start blinking at you at 3.3V, but I've never seen it.
The battery shouldn't be run down below about 2.8 volts in any case.
I have heard the LT has a cutoff somewhere below 3.3V, but I've never gotten there either.
Some people claim it cuts off and some claim it doesn't, but I wouldn't depend on it in any case.

I recharge at 3.8V, but I think a good compromise would be 3.5V. That ought to get you an easy 8 or 9 hours on a 1600mah battery. If you have a 2000mah, you could probably go 12 hours before 3.5V.

BTW, after a few charges, your battery should charge to 4.2V

If you want a super long lasting battery, get a 2250mah Panasonic CGR18650CH for $10 shipped from Orbtronic.com
It's superior to the AW batteries in every way. See the Lavatube forum for more details.

Awesome info, thank you so much Sailorman!

 

[sailorman]

Oh no. we meet again.

HA!! Don't forget, I'm gonna show up there for that beer!

But, what does this mean?

HOWEVER. If you actually consider that these are 3.7 volt batteries and we are overcharging them to 4.1 just inside the safety shelf of the battery...

All my 18650s charge to 4.20V +/- .01V. The max. safe charge is 4.23-4.25V, depending on who you ask. Mine actually stays at 4.0-4.2 for hours, even though I know it's supposed to be nominal 3.7V, I almost never get there.

 

[newq]

HA!! Don't forget, I'm gonna show up there for that beer!

If you made it here, I sure would Sailor Seriously. Have a good one!

 

[mynameisrob]

4.1V is exactly where you want if for a fully charged battery, and a battery that's basically dead would show around 3.2V.
Not letting your batteries drain all the way down will help them last longer bc you won't use a full charge cycle each time that way. If you want to recharge your batts when they get to about 50% you'll want to throw them back on the charger when they hit 3.6V-3.7V. I always put my batteries back on the charger at around 3.6-3.7V and it works really well bc not only are you using a half charge cycle everytime instead of a full one, but you also skip over getting that drop in vape performance that happens as a battery drains closer to empty, since your recharging them again before they get low

 

[sailorman]

4.1V is exactly where you want if for a fully charged battery,....

Wait a minute. 4.1V?? Everything I know is wrong?? I have 6 18650's and over a dozen 14500s and CR123As from 3 different manufacturers around here and every single one of them comes off the charger (both chargers) at 4.2 to 4.21V. Not to nitpick, but I would't want to scare anybody into thinking their batteries were overcharging. The first couple charges, they top out at about 4.17 or 4.18, but after that it's 4.2 - 4.21V every time.

 

[newq]

Wait a minute. 4.1V?? Everything I know is wrong?? I have 6 18650's and over a dozen 14500s and CR123As from 3 different manufacturers around here and every single one of them comes off the charger (both chargers) at 4.2 to 4.21V. Not to nitpick, but I would't want to scare anybody into thinking their batteries were overcharging. The first couple charges, they top out at about 4.17 or 4.18, but after that it's 4.2 - 4.21V every time.

Not sure But I thought 4.2 was overcharged. In another thread I had heard it depends on the quality of the Digital multimeter.

Something about if the resolution of the multimeter was +/- .2 it could read a 4.17 charged batt as 4.2 and hence the actual cvoltage may be 4.1 or something of that sort. My pila charger pulls my AW18650 Batteries off at 4.1 volts. My cr123a 16340's come off at 3.6 I believe but my reading are incosequential as I have a cheap DMM made in china but claims .0002 +/- accuracy if thats to be believed. Just a thought. This was raised in another thread is the only reason I mentioned it.

 

[sailorman]

Not sure But I thought 4.2 was overcharged. In another thread I had heard it depends on the quality of the Digital multimeter.

Something about if the resolution of the multimeter was +/- .2 it could read a 4.17 charged batt as 4.2 and hence the actual cvoltage may be 4.1 or something of that sort. My pila charger pulls my AW18650 Batteries off at 4.1 volts. My cr123a 16340's come off at 3.6 I believe but my reading are incosequential as I have a cheap DMM made in china but claims .0002 +/- accuracy if thats to be believed. Just a thought. This was raised in another thread is the only reason I mentioned it.

Hmm.. A multimeter that is +/- .2V would be pretty worthless unless you were reading off the 200V scale. If it read 4.1, it could be 3.9 which is undercharging, to 4.3, which is a definite overcharge. I think you may mean +/- .02V. That could read a 4.17 as a 4.15 to 4.19 and a 4.23 as 4.21 to 4.25, which is borderline overcharged. That's still not so great, but roughly useable. My meter claims something like .001 accuracy too, which I divide by 10 to get a reasonable estimate, so more like .01, which is good enough.

Anyway, you have to figure that accuracy and resolution are different things. It could have a .00001 resolution, but only be accurate to the nearest 0.1V, which makes all that resolution worthless.

 

[newq]

I dunno sailor I have never worked with anything where such miniscule reading were of any consequence nor have I investigated the difference between resolution or accuracy in DMM to be honest. Usually small voltage discrepancies for my main uses of the meter were incvosequential until now I suppose. I have a nice fluke i use for work but even still the meter isnt used to its potential. It is mainly used for determining true rms of high voltage wiring.

Heh all this good techy stuff