No, that's wrong. There is no way they would consume anywhere near 40W average power. You don't get the fact that speakers are rated in peak power and you won't be using anywhere near that power when playing music. I would be very surprised if you used more than 1/2W average power even listening to loud music.

The speakers rated 80W Peak Power and 20W RMS. i know peak power isnt saying nothing cause its only for a few sec. anyway can u explain in a simple way? sorry but my english is very bad.

 

http://www.madisoundspeakerstore.co...urasound-ns3-193-8a1-3-black-cone-wide-range/

How Do i measure this speaker current? power is 20W RMS.

Going back to post number one, to measure the speaker current, you measure it with a current meter. Connect the power supply through an amp meter and turn the music on. When it sounds about right, look at the current the meter is showing. This works pretty well with an old, analog meter, the kind with a needle. A digital meter will jump around and be hard to read.

 

What are your concerns with the 5 ampere-hour battery?

 

The speakers rated 80W Peak Power and 20W RMS. i know peak power isnt saying nothing cause its only for a few sec. anyway can u explain in a simple way? sorry but my english is very bad.

You are not understanding that with music, the average power is always going to be much lower than peak.

 

+1
Your speaker's efficiency is 80db at 1watt/1meter, so it only needs 1 watt of power input to produce 80 decibels of sound at 1 meter distance from the speaker.

For reference, normal conversation is 60-65 db, a normal phone dial tone is around 80db. 90-95 db is getting loud to very loud. So, if you are using these at normal listening levels you may not use even 1 watt average power.

The battery life is dependant on how LOUD you want the sound.