# What is the definition of Ah unit?

1. ## What is the definition of Ah unit?

What is 1Ah? Don't give me the exact definition regarding the electric charge passing through a point etc. Give me one (or more ) examples. For instance when I say that a battery is 10Ah what should I exept from this battery?
Thanks,
D.

•

2. ## ah unit

I think that question has already been answered many times on this forum. Oh well ...

Multiply current times hours. An ideal 10Ah battery will deliver ten amps for one hour, or one amp for ten hours, or two amps for five hours, etc.

However, a real-world battery isn't perfectly linear like that. If you draw high current from the battery, it will probably deliver somewhat less than 10Ah of capacity. If you draw very low current, it will probably deliver somewhat more than 10Ah. The battery's data sheet should tell you what to expect under various load conditions, temperature, age, etc.

•

3. ## unit ah

Some interesting examples and hints on Ah and batteries you can find here:
http://www.a-aengineering.com/batteryfaq.htm

•

4. ## what is ah?

In Europe and rest of the world, capacity of an battery is usually given at 10 hour basis. Some manufacturers give it at 20 hour basis in specific applications (e.g. Sonnenschein, Austria).

When you have battery of 10Ah in Europe it is always: 1A discharging current for 10 hours, end voltage 1,80V/cel, 20 degC ambient temperature ( not any other combination) if otherwise stated.
In USA ambient temperature (table value) is 25 degC and in Europe is 20 degC.

Always, one need to look at manufacturer's discharging tables and datasheets and see all combinations of parameters for given battery: temperature, end voltage, discharge current, time, ...).

In UPS applications end voltage is usually 1,60 V/cell.
In Solar applications capacity is given at 100 hour basis.

Regards for Greece from Serbia.

--[[ ]]--