What do mA and mAh stand for?
mA is the unit (mili Ampere) used for the charging current, which you can compare to “the speed of charging”. The higher the mA the faster Eneloop batteries will charge. mA is also used for the discharge current. Eneloop chargers generally charge between 150 and 1500mA depending on the charger.
mAh stands for milliAmpere hour. This refers to the amount of energy (capacity/charge) that a battery contains. On every Eneloop there is a mAh number written. This is the total capacity the battery can contain. A regular white Eneloop AA has a capacity of 1900mAh.
What is the difference between mA and mAh? And how do they work?
So how does it (not) work!
Let`s take a standard Eneloop with a capacity of 1900mAh. When you have a charger that uses a charge current of 100mA, the battery will be fully charged in 19 hours. 19 hours of 100mA = 19*100=1900mAh
This is a simplified way of looking at it, but not really the way mAh actually works.
It`s the opposite:
To simplify it, you take a battery with 1900mAh and a device (let`s take a flashlight for example) that uses a low current of 100mA. The battery will take 19 hours to discharge the battery from 1900 till empty. So 19 hours of discharge at 100 mA equals 1900 mAh.
Isn`t that the same? Why can`t you use that with charging instead of discharging?
Let`s go back to the first example. A battery charger uses a charge current of 100mA. When you charge the battery for 19 hours you will have 1900mAh charged. This is also written on a standard Eneloop, so the 1900mAh of capacity is now inside the battery.
Now you extend the charge time to a total of 25 hours. This would imply that you do 25*100mA which would result in 2500mAh. This is the problem! A 1900mAh battery can only hold 1900 mAh even if you put 2500mA into it.
Still not sure?
Try to compare it with a 1-gallon jug. Fill the jug with 1 gallon of water and it`s full. When you continue throwing water into it, it will still only be 1 gallon of water inside the jug. When you empty the jug, only 1 gallon of water would come out. Simple.
This is a very basic way of looking at it. In real life, the mAh depends on a few more factors, like the discharge current that is being used, the age of the battery (how much it is used), and the (ambient) temperature.
More questions about charging (Eneloop) batteries
+ Is slow charging better than fast charging for Eneloops?
+ What do mA and mAh stand for? And what’s the difference?
+ How many times can Eneloop rechargeable batteries be recharged?
+ Do Eneloop batteries need a special charger?
+ How long do Eneloop batteries hold a charge?
+ What is the recommended charge current for Eneloops?
+ What’s the best Eneloop charger?
+ Eneloop Voltage – what’s the deal
+ Can you overcharge Eneloop batteries?
+ What is the maximum charge voltage for Eneloops?
+ Do I need to charge my new Eneloop batteries before I start using them?
+ Should I discharge my Eneloops completely before charging them?
+ How long does it take for Eneloop to charge?
+ How do I need to Refresh my Eneloops?
+ Can I refresh Eneloops if I don’t have a charger with a refresh option?
+ How many years do Eneloops last?
Advanced Eneloop charging info
+ What is -dV/dt charging? (termination)
+ What is 0 dV/dt termination?
+ How are Eneloops tested to claim a 2100 cycle life? (IEC 61951/ JIS 8708)
+ Non-charge related questions can be found in the Eneloop FAQ