What should the Voltage reading be on charged battery?

[livemusic]

First, I am pretty ignorant of anything electronic, lol.

What about a Nitecore NL183 battery, 2300mAh, 18650, 3.7v, 8.5Wh. What does Wh mean? Second, after I charge the four NL183 batteries on my Nitecore Intellicharger I4 charger, the readings are 4.14 - 4.17. Is that volts? Is that good? If the battery is rated 3.7, why am I getting 4.1x? Is the range of 4.14 to 4.17 for four batteries acceptable? Sorry for being so ignorant, lol.

The above stems from my having a TM16 flashlight and it quit working months ago and tomorrow, I should have some new Nitecore batteries delivered. So, I can install new batteries and see if it works.

Lastly, might as well ask another question. For a AA or AAA battery, after charging, should the reading be 1.5 or just what for me to consider the battery 'good?' Is there a certain level a 1.5v battery should charge to before discarding it?

EDIT: The meter I have is a DMiotech Smart-C multimeter. I dial it to the left of 'due north' on the '20' setting.

 

[staticx57]

Quick answers: Wh or Watt-hours is the capacity of the battery.

The 3.7v is the nominal voltage of the cell or the cell at storage conditions more or less. The working voltage of the cell is 4.2 volts down to likely 2.7 volts. The NL138 will have a protection circuit that will protect it from over discharge (voltage dropping too low).

 

[StorminMatt]

The 3.7V figure for non-LiFePO4 Li-Ion batteries is what is called a 'nominal voltage'. It is to some degree the average between the voltage of a fully charged and fully discharged battery. However, the actual voltage is going to vary with the state of charge from around 3.0V for a fully discharged battery to around 4.2V for a fully charged battery. If your batteries are coming off the charger at 4.14-4.17V, that's OKAY for fully charged batteries. This voltage can vary, depending on the age and condition of the battery as well as the charger. Another charger might give entirely different results.

As for AA/AAA batteries, the voltage here depends on chemistry and state of charge. What type of AA batteries (is alkaline, NiMH, or primary lithium) are we talking about?

 

[livemusic]

...As for AA/AAA batteries, the voltage here depends on chemistry and state of charge. What type of AA batteries (is alkaline, NiMH, or primary lithium) are we talking about?

Nothing is simple, is it. I have...

alkaline (Duracell)
NiMH rechargeable (Rayovac, Energizer)
Eneloop rechargeable

The Eneloop does not say what type it is!

Say, why are the Duracell AA batteries 1.5v and the rechargeable ones 1.2v? That surprises me but what do I know. Not much.

EDIT: The 4.14 - 4.17 reading for my Nitecore NL183 after charging... so, it's normal. Does this mean that these batteries are 'good,' or could one of them still be defective and making my Nitecore TM16 flashlight not work?

 

[StorminMatt]

Eneloop is NiMH. All NiMH cells fully charge to around 1.4-1.5V. As the cell is discharged, voltage rapidly drops to around 1.25V and stays there until the cell is almost discharged. It then rapidly drops to around .8-1.0V, at which point it is fully discharged. Alkaline batteries, on the other hand, are around 1.55-1.5V fully charged and steadily drop to around .8-1.0V when fully discharged.

The fact that alkaline batteries are rated at 1.5V nominal vs 1.2V for NiMH is somewhat arbitrary, especially since alkaline batteries are really only 1.5V when fairly new. The voltage of NiMH is actually higher than alkaline batteries over much of the discharge cycle, particularly at higher current draw (which causes the voltage of alkaline batteries to sag lower). Why NiMH batteries have a lower nominal voltage is unclear, but is likely due to the relatively constant voltage plateau of NiMH.

EDIT: The 4.14 - 4.17 reading for my Nitecore NL183 after charging... so, it's normal. Does this mean that these batteries are 'good,' or could one of them still be defective and making my Nitecore TM16 flashlight not work?

It is possible that a light might not operate correctly with these cells if the current draw exceeds that which trips the protection circuit in these cells.