# How to convert battery capacity from Wh to Ah (or vice versa)

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• #1
as127
Level 15
The question as in the title, maybe someone will take pity and tell you
I have 2 notebooks, one has a 4.4 Ah battery and the other 28 Wh
(both voltages the same 11.1V)
How to convert from one value to another? (to compare)
Chargers have the same dimensions, voltages and polarities,
different powers (2 A and 3.25 A, both 20V), identical plugs
can I use them interchangeably?
But there are other computer makers: twinhead and lenovo
The manufacturer of the chargers is the same (LI SHIN), and the batteries are probably the same
but I can't read it because it's written in bushes, probably in Chinese
#2
Maly
Level 32
You can probably assume that from the first one we will get 4.4A in an hour, so at a voltage of 11.1V (4.4 * 11.1) we will get the power of almost 49W, i.e. for an hour 49Wh.

The second, when it has 28Wh, for an hour with this voltage, we can "take" the current 28 / 11.1 = 2.5A. So how for an hour is 2.5Ah.

It turns out that this 4.4Ah is more powerful, so it must have a more powerful power supply. This 3.25A will be from him.

Regards.
• #3
azaghorth
Level 6
Power, P=U*I, where U is the voltage and I is the current
Energy W=P*t, where t is time (usually in hours)
For example a battery with 3.7V and 5000mAh can provide 18.5Wh (3.7V times 5Ah), where 5000mAh=5Ah.