Audio Systems: Car audio - coverting battery power to AC for show piece, dry cell batteries, custom speaker box

Question
I am building a custom speaker box enclosure that attaches to a bike, it will have have two dry cell batteries to power the speakers, subs, amp. It wont last long at high volume, and I plan to show it indoors mostly. I would like to have the option of switching from the battery power of the mobile sound system, to ac power when stationary... looking for a way to plug it into a regular 110 outlet. What do i need to get to convert? and can i charge the batteries in the process?

Answer
Yes, to all the above.

But, we need to know what batteries you are using and how much current the speakers will draw.

The simplest method is a 110 converter or inverter that will provide the voltage you seek.

You can find such power converters at Radio Shack and other electronic stores.  I found several of them online by doing a simple google search.

Once you know what power you need you can select one that fits best to your needs.

It is easier to use a separate battery charger because building a dc supply that runs the speakers and charges at the same time is not easy. It involves really two supplies and some switches all built into one. If you can use a power pack for a notebook pc they usually have such supplies already designed for this purpose; they use voltages in the 7 to 13 volt area so you would need to know what batteries you are going to use for the bike speakers.

Best wishes,
C