How many volts are the 18650 batteries fully charged?

[Traijan]

Yes, I just looked it up and everywhere I looked shows 1.5 volts but I know we have a 2nd multimeter that is still in one of the boxes we've not yet unpacked from the move here so when I get to that box I'll try it out with a second multimeter.

If my meter is off then it would read 4.2 when fully charged if it's reading 3.9 now when fully charged I think. I'll try to find the box with the 2nd meter to see what it reads sooner rather than later now that my curiosity is peaked.

 

[Maurice Pudlo]

4.20 volts, my current charger gets them to 4.15 and calls it quits. I'm OK with that. An earlier one would easily go beyond 4.20 volts if you didn't pull them lickety split. Had to ditch that one.

Maurice

 

[beckdg]

Shouldn't a fully charged AA battery read 1.5V?

About that. Due to the charging cycle depending on the increased resistance of the cell against the charge to stop the charge it isn't an exact number. For lithium cells the voltage is the stopping number rather than the resistance.

 

[edyle]

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.

actually, I do believe the traditional NON-rechargeable carbon/zinc common batteries are 1.5 volts, then there are the rechargeable NiCd batteries which are 1.2 volts.

 

[edyle]

You should also put your meter directly on the charger and check the charging voltage.

one of my chargers reads 4.25 and the other 4.28 right now.

and its a real cheapo multimeter I have.

not sure if that's the same numbers I got first time I measured them almost a year ago, but I do recall which one was higher and it's the same one as now.

 

[PapaSloth]

Yes, I just looked it up and everywhere I looked shows 1.5 volts but I know we have a 2nd multimeter that is still in one of the boxes we've not yet unpacked from the move here so when I get to that box I'll try it out with a second multimeter.

If my meter is off then it would read 4.2 when fully charged if it's reading 3.9 now when fully charged I think. I'll try to find the box with the 2nd meter to see what it reads sooner rather than later now that my curiosity is peaked.

Sounds like you have it set to kilometers instead of miles

 

[StarreLabelle]

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

There are different types of 18650 batteries, and I found out they cause my devices to function differently depending on whether it's a 1600, or 2500, etc. You get what you pay for.

 

[WattWick]

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.

Some hobby chargers calculate internal resistance. Even then it's just an educated guess as it's hard to tell how much of the resistance is in the circuit connecting battery to charger.

I have often thought about getting an 18xxx cradle and do a little testing myself... Got the charger for it; just can't find the motivation. Doubt I know enough about electricity to come up with anything worthwhile. Don't want to be "that guy" - throwing numbers out there without knowing the minute details on how they got that way.