How many volts are the 18650 batteries fully charged?

[Traijan]

Hi,

So, I was following the advise of a topic here or well... someplace that suggested that until I get used to how my Stingray X (and my vaping regiment) discharges the battery (18650) that I should be checking the battery charge with my multimeter so that I get a rough idea when it needs to go back on the charger so as to prevent draining it down to 0.

I don't know why but I thought these batteries are 4.2v when fully charged but taking one off the nitecore i2 charger when the three amber lights are fully lit up only produces about 3.7 or 3.8 (possibly 3.9, I can't be certain as it was this morning that I checked them) so thought I'd ask...

What should the voltage be on a fully charged 18650 battery?

One is an MXJo 18650 (had to buy a new one due to my stupidity but that's another story) and the other one is an Vamped Vapor cell 18650 both listed on the wrappers as IMR.

Thanks

 

[edyle]

nominal 3.7 volts.

3.3 to 4.2

4.2 is fully charged

 

[eratikmind]

How long have you had these batteries?

 

[Nytebreed]

4.2 volts full charge. I usually try to swap out @ 3.4-3.6 volts.

I am unfamillair with the MXjo, but keep in mind the Vamped is a 20a continuous drain battery not 40 like advertized.

 

[edyle]

Hi,

So, I was following the advise of a topic here or well... someplace that suggested that until I get used to how my Stingray X (and my vaping regiment) discharges the battery (18650) that I should be checking the battery charge with my multimeter so that I get a rough idea when it needs to go back on the charger so as to prevent draining it down to 0.

I don't know why but I thought these batteries are 4.2v when fully charged but taking one off the nitecore i2 charger when the three amber lights are fully lit up only produces about 3.7 or 3.8 (possibly 3.9, I can't be certain as it was this morning that I checked them) so thought I'd ask...

What should the voltage be on a fully charged 18650 battery?

One is an MXJo 18650 (had to buy a new one due to my stupidity but that's another story) and the other one is an Vamped Vapor cell 18650 both listed on the wrappers as IMR.

Thanks

Don't let it drain down below 3.3

Check Baditudes blog on battery info - see my sig for link

 

[bluecat]

4.2 .... then ish depending on the accuracy of the mm.

Description

These are the newest version of the MXJO IMR Safe chemistry LiMN 3.7V rechargeable batteries in an 35A 18650 2500MAH size. These cells can handle high amperage and are safe to use in series / multi-cell applications. Can be charged with any LiIon battery charger with 4.2V output.

Specifications

-Capacity:2500mAh
-Nominal Voltage : 3.7V
-Max continuous discharge :20A
-Max. Discharge Current : 35A
-Dimensions : 65*18.24MM (+/-0.05)mm
-Operating Discharge Temperature : -10 to 60 Degrees Celsius
-Standard Charge : CC/CV
-Cycle Life : > 500 cycles
-Weight : 65g

Caution

-Do not over-discharge/overcharge, if allowed to drop past2.5 volts, chargers will no longer be able to charge these batteries
-Recharge empty batteries (resting voltage ~3.6V) as soon as possible
-Leaving LiIon batteries in discharged state will incur irreversible damage (capacity / cycle loss)
-Do not short circuit (will release tremendous current)
-Do not dispose of in fire


What I found on the MXJo.... People are saying they are re-wrapped LGs.. similar stats. Not sure if true or not.

Then this

Charging Lithium-Ion Batteries

 

[Poisontail]

I charge at 3.6 switch on my charger and they cap out at 4.2 which is perfect voltage

 

[Traijan]

4.2 volts full charge. I usually try to swap out @ 3.4-3.6 volts.

I am unfamillair with the MXjo, but keep in mind the Vamped is a 20a continuous drain battery not 40 like advertized.

Hmm, wondering then if I should ever buy them again if they're misrepresenting their product. Anyway, it was a one off purchase of the Vamped battery as it was at a vape shop that I don't normally visit when I overheated the original battery (the MXJO) on the way home the day I bought it. Still, doesn't make me too happy to hear that they're misrepresenting their products.

How long have you had these batteries?

Only a few days. Bought the Vamped about 3 or 4 days ago, and the MXJO I bought the new one just yesterday.

 

[Traijan]

I charge at 3.6 switch on my charger and they cap out at 4.2 which is perfect voltage

Pretty sure there is no switch on my charger. When I pulled one off and tested it after the three amber lights were all lit up I was surprised not to find 4.2v, maybe the Nitecore i2 isn't really a good charger for this application. Although, I thought I'd read in many many places that people recommend this charger for an inexpensive reliable charger.

 

[iamthevoice]

Did you happening to check the starting voltage of those batteries before charging? When Li batteries are stored when over-depleted (below 2.5v), they are often damaged. Probably not the case, but you never know. A good way to check is to measure the internal resistance of the battery itself, which should be around 20 milliohms or less (0.02 ohm); more than that is usually indicative of a damaged internal structure.

 

[eratikmind]

Well, either the batteries will not take a full charge or the charger is faulty.

I am not familiar with any of the listed items.

 

[pmcode]

maybe the Nitecore i2 isn't really a good charger for this application. Although, I thought I'd read in many many places that people recommend this charger for an inexpensive reliable charger.

It depends on who you ask, truly. As with just about everything, there is an opinion on everything. "opinions are like ***holes, everybody has one, and everybody thinks everyone else's stinks."

But.....(and take this with a grain of salt) I have read on a vendor's site (can't remember the name right now, but it was a flashlight site, not vaping) that the nitecore's may not be all that. Something to do with the pulses they charge with, or something. This guy was recommending Xtar's, and one other brand, can't remember the name. I went with an Xtar 4 bay, cause I needed to be able to charge 2 26650's together, and their 4-bay charger has a neat feature where you can put a fully charged battery in bay 4 and use it to charge a usb device (phone, whatever). Thought that was pretty cool.

Hope that helps muddy the waters even more....

 

[Traijan]

Did you happening to check the starting voltage of those batteries before charging? When Li batteries are stored when over-depleted (below 2.5v), they are often damaged. Probably not the case, but you never know. A good way to check is to measure the internal resistance of the battery itself, which should be around 20 milliohms or less (0.02 ohm); more than that is usually indicative of a damaged internal structure.

Okay, maybe I'm doing this wrong, but I'm using my multimeter and have tried it on each of the resistance settings from 200 to 2000k touching the positive lead to the positive side of the battery and the negative to the negative and it reads nothing. I know it's not a faulty multimeter as it works on other projects that my wife has to do for her work so I must be doing something wrong, or it's simply got no resistance instead of the 0.02 Ohm that you mentioned.

No, unfortunately I did not think to check the battery when I first got it as the sales person pulled it straight out of an unopened pack so I figured that he wasn't trying to sell me his second hand battery that he's been vaping on for months or longer.

In any event I just pulled it off the charger when it says it's done charging and it registers exactly 3.93v I think I may leave it on longer next time after the charger shows it's done to see if maybe it "trickle charges" it up to the 4.2v

 

[edyle]

Okay, maybe I'm doing this wrong, but I'm using my multimeter and have tried it on each of the resistance settings from 200 to 2000k touching the positive lead to the positive side of the battery and the negative to the negative and it reads nothing. I know it's not a faulty multimeter as it works on other projects that my wife has to do for her work so I must be doing something wrong, or it's simply got no resistance instead of the 0.02 Ohm that you mentioned.

No, unfortunately I did not think to check the battery when I first got it as the sales person pulled it straight out of an unopened pack so I figured that he wasn't trying to sell me his second hand battery that he's been vaping on for months or longer.

In any event I just pulled it off the charger when it says it's done charging and it registers exactly 3.93v I think I may leave it on longer next time after the charger shows it's done to see if maybe it "trickle charges" it up to the 4.2v

Ok, listen; you cann't measure the internal resistance of a battery with some meter; it's something you have to calculate- basically if your battery has high internal resistance, you might meansure the voltage of it as 4 volts, but when you connect it to the coil and measure it (on an rda for example) while firing the coil, you see a drop in the voltage, like drop from 4 volts to 3.5 volts.


the lithium batteryies are better kept between 3.5 to 4 anyway.
4.2 is the max, but it is also a small stress on the battery.

 

[Traijan]

Thanks for the info edyle, I had a feeling if I couldn't make it work the way I was trying to, then it must be the wrong way of trying.
So then that 3.93 volts is okay at full charge and I'm not going to worry about it any further for now.

Much appreciated.

 

[edyle]

Thanks for the info edyle, I had a feeling if I couldn't make it work the way I was trying to, then it must be the wrong way of trying.
So then that 3.93 volts is okay at full charge and I'm not going to worry about it any further for now.

Much appreciated.

you didn't actually mention whether you have another battery that measured 4.2 so I kinda presume maybe one of the probes on the multimeter is flakey or the multimeter is a bit off; maybe the battery justs needs some more time to charge; my batts take some 8 hours to charge.

 

[PapaSloth]

Pretty sure there is no switch on my charger. When I pulled one off and tested it after the three amber lights were all lit up I was surprised not to find 4.2v, maybe the Nitecore i2 isn't really a good charger for this application. Although, I thought I'd read in many many places that people recommend this charger for an inexpensive reliable charger.

I have the same charger, and my batteries always read 4.2 when they're fresh off the charger. This includes an MXJO 18350, if that's worth anything. Maybe your meter isn't working correctly, or the battery isn't screwed in fully?

 

[Traijan]

I tried it on a freshly charged AA battery and it reads 1.2v so I assume it's accurate enough and that when it's telling me that the good battery is 3.93 volts that it's pretty close.

I have yet to wear the two good 18650 batteries down low enough to take more than a couple hours to charge them up. The last one that I charged after using it for a day of my normal vaping still only took about 1.5 to 2 hours to charge up. But I vape much less than most people even though I used to smoke cigarettes at the tune of 1 to 4 pad.


Can you tell me, is it a bad thing if I recharge my 18650 batteries before they are down to the 3.5 or 3.6 volts that somebody posted in this topic as the time they recharge? Is it safe to assume that putting them on the charger when they're only at 3.7 or 3.8 volts will not do them any harm?

I'll probably pick up another battery in the next few days/weeks just to satisfy my curiosity to see what it reads when I buy it and what it shows when the charger says it's fully charged.

 

[edyle]

I tried it on a freshly charged AA battery and it reads 1.2v so I assume it's accurate enough and that when it's telling me that the good battery is 3.93 volts that it's pretty close.

I have yet to wear the two good 18650 batteries down low enough to take more than a couple hours to charge them up. The last one that I charged after using it for a day of my normal vaping still only took about 1.5 to 2 hours to charge up. But I vape much less than most people even though I used to smoke cigarettes at the tune of 1 to 4 pad.


Can you tell me, is it a bad thing if I recharge my 18650 batteries before they are down to the 3.5 or 3.6 volts that somebody posted in this topic as the time they recharge? Is it safe to assume that putting them on the charger when they're only at 3.7 or 3.8 volts will not do them any harm?

no it's a good thing.

the operating range is 3.3 to 4.2
3.4 to 4.1 better for the battery
3.5 to 4.0 better yet
3.6 to 3.9 better yet yet

 

[PapaSloth]

I tried it on a freshly charged AA battery and it reads 1.2v so I assume it's accurate enough and that when it's telling me that the good battery is 3.93 volts that it's pretty close.

Shouldn't a fully charged AA battery read 1.5V? If your AAs are reading 1.2V and your fully charged 18650s are reading 3.93V, it sounds like something is up with your meter.