Is there way to construct an 18650 battery pack with built-i?

[MatthewAiden]

Hello guys, the weather is so fine, and I want to ask some advi...ses. Please be kind
I'm a DIY enthusiast especially in electronics. I'm actually building a portable Playstation 2 Slim with an IPS display, so that it would look like a Wii U controller. It's my first large electronic endeavor.

However, being portable, I'd need it to be powered by rechargeable batteries. I'm very confused on how to approach the power part of this project. I'll try my best to be detailed as possible! I look forward towards your answers!
The Little Details

Looking around, I concluded that a battery pack of 18650s (3S) would do a good job, it seemed straight forward too. Connecting three of them in series will produce a maximum of 12.6V. It's also a bit common, therefore a lot of information about the batteries can be found, and even be salvaged from laptop battery packs.

I have some details on the electronics included in the project so far:

Sony Playstation 2 Slim (Model 75003)

Operational Voltage: 8.5V
Power Consumption: 6 A Maximum
Innolux N070IDG (Yeh, I love nice screens )

Type: IPS LCD
Resolution: 1280x800
Size: 7 Inch Diagonal
Operating Voltage: 9-12V (Best at 12V)
Consumption: 190-210mA (full brightness) (Indicated from Bench power supply)
Display Interface: Includes Interface board of HDMI, VGA, 2 x AV.

[Shadow]

Best to browse or ask on the Ben Heck forums for that sort of stuff.