Question : How to properly read battery level using a multimeter?

[DiscoPotato]

Hello guys, can someone please explain or tell me how to properly read battery level using a multimeter.
I just recently purchase a multimeter since from what I read here on the forum, owning one is very important for safety as well as for avoiding any hazard when creating a coil. I cannot express how helpful a multimeter is, since with it, I was able to rebuild my ce5 and vivi nova 1.8ohm 2.2 ohms (this might not sound impressive but I'm proud of it, I try to lear as much as I can but taking it one step at a time lol)


Now back to my question, using a multimeter, how would you know if the battery is fully charge and if it already needs to be recharge?
I have 2 Efest IME purple battery, one is a 18500 1000mAh and the other is 18650 2500mAh, both are 3.7v.


What value should the multimeter shows on the lcd display if the battery is fully charge? and when it needs to be recharged?
My charger shows green light when the battery is done , but I'm still curious as to what value should I look for to check the status level of my battery.


I'd appreciate any feedback

 

[Jockamo]

4.2V would be a full charge and I recharge somewhere around 3.5 V. 3.5V on my sigelei shows 10%.
When using the meter to check resistance touch the leads together and subtract that value from your coil measurement.

Unless I have been doing it wrong all these years. Either you just learned something or we are both about to learn something when the post pour in telling me I'm wrong.

 

[oseigneur]

I confirm that a freshly charged battery will display 4.2V.
In principle, you can drain your battery as low as 2.5V. However, power will be so low at 2.5V that in practice you will start the charge process before reaching that level.

The capacity of 2500mAh of your battery is measured when it is drained down to 2.5V.
If you use your battery from 4.2V until 3.5V, it will have delivered about 1500mAh

Source: dampfakkus (where you can see discharge curve for batteries)
***.dampfakkus.de/akkutest.php?id=509

 

[Rickajho]

You need to find the range on your selection knob for DC volts. It should have multiple range settings and you want to turn it to the lowest range - typically "20" for lower than 20 volts on most meters. For e-cig batteries that will get you a reading with two positions right of decimal. A fully charged battery will read 4.20 volts. If your charger isn't working right and is over-charging it may read a battery coming right off the charger as, say, 4.27 volts - which would be a bad thing. Checking battery voltage with a meter is always a good idea.