# Amp Hours - please educate me

Discussion in 'Tech/Mech General' started by laser101uk, Mar 14, 2014.

1. ### laser101ukFunster

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so, I am a little confused by the term amp hours. I understand that my battery is say 100 amp hours, I assume this to mean that if i was running a 1 amp appliance I would then be able to run it for 100 hours ( I realise not to run the battery below half way) so with this in mind my 1 amp appliance would run for 50 hours.

Therefore If my TV is rated at say 4 amps, according to my thinking I use 4 amps per hour from my battery full of amps....

I am sure I have got this wrong, if anyone can please enlighten me I would be grateful...

Thanks

Steve

2. ### MikeDFunster

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I am no expert but that is about right. So your tv would run! workaround twelve hours

3. ### gozomikeFunster Life MemberLife Member

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Spot on Steve :thumb:

4. ### MicrochipFunster

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This the best way it can be explained

The Amp Hour rating tells you how much amperage is available when discharged evenly over a 20 hour period. The amp hour rating is cumulative, so in order to know how many constant amps the battery will output for 20 hours, you have to divide the amp hour rating by 20. Example: If a battery has an amp hour rating of 75, dividing by 20 = 3.75. Such a battery can carry a 3.75 amp load for 20 hours before dropping to 10.5 volts. (10.5 volts is the fully discharged level, at which point the battery needs to be recharged.) A battery with an amp hour rating of 55 will carry a 2.75 amp load for 20 hours before dropping to 10.5 volts.

Keith

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