TDA797 for DIY Bluetooth Speaker

[claymca]

Attempting to put together Bluetooth speaker. Similar to the one here: DIY Custom Pelican Mini Portable Boombox w/Bluetooth & T-Class Amp! - YouTube

Parts I already have.

Speakers:HiWave BMR12 Compact 2" Full-Range Square Speaker 12W 8 Ohm | 299-208

Case: Pelican 1050

Amp: TDA7297 Version B 2 15W Audio Amplifier Board Dual Channel AC DC 12V | eBay

I want to use a battery that remains in the case. I also want to use the speaker while it is charging.

Here is a block diagram with how I am thinking it should be put together. Any help is appreciated.

 

[Mihkus]

Isnt that battery a bit too small?
2,6Ah aint that much... + those step down thingy's, I dont think its going to sit together very well..
Yet if you can push out those "2A" from a regulator... that heat output at 5V 2A would blow the regulators.
But... Now theres switching type of regulators that have very high effiency..

 

[claymca]

Would something like these work?

DC DC Adjustable Step Down Voltage Regulator Module | eBay

Pololu - 5V 3A BEC Step-Down Voltage Regulator

 

[claymca]

I found this. i think this will work.

DC DC Dual Double Output 7 16V Step Down Buck 1 16V Max 6A Converter Regulator | eBay

 

[claymca]

So after some research i am thinking about using this battery holder:6 AA Cell Battery Holder | 140-976

With six of these batteries: UltraFire Protected 18650 3.7V 2400mAh Lithium Batteries (2-Pack Grey)

I will use a DC-DC dual double output 7-16V Step-down BUCK convertor to send power to the bluetooth module and amp.

Is there a PCB already built that I could use to charge the batteries and use the AC power while the battery is charging?