# Charge and discharge

Discussion in 'General Electronics Discussion' started by Gregg Sanders, Sep 7, 2015.

1. ### Gregg Sanders

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Sep 7, 2015
Hello.Im busy with a personal project and i want to know if there is a way that i can store 220v in a few minutes and release the 220v over a period of a few minuts. i thought capacitors would be my solution but any suggestions at this point would be appreciated thanks.Out put power that i want to achieve is about 4 kw.

2. ### Harald KappModeratorModerator

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Nov 17, 2011
Am I right in assuming that you mean AC (as suggested by the value of 220 V)?
Then the answer is no. AC cannot be "stored". You will need an "uninteruptible power supply", short UPS, that stores the energy in DC form (typically within an accumulator) and bridges a loss of primary power by generating an AC output from the stored energy.

3. ### rickselectricalprojects

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Feb 1, 2015
as Harald Kapp said above, you cant store ac voltage in capacitors. in fact applying ac voltage to electrolytic capacitors will blow them up and is my favorite way of blowing them up!!!

4. ### oz93666

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Dec 7, 2014
4kw for a few minutes is a lot of energy .... forget capacitors or coils (unless you have thousands of \$ to spend)

your only option is batteries or fly-wheel storage.

5. ### AnalogKid

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Jun 10, 2015
4 kW for a few minutes is 1 million watt-seconds. That's a lot of energy storage without even getting into the AC/DC/AC conversion at kilowatt levels. Here is a first-pass, seat of the pants analysis. Based on CCA ratings, a large car battery is good for about 1000 A for 30 seconds, or 360,000 w-s. You would need 3 such batteries for 4 minutes of storage, plus another one to cover inefficiencies.

ak