Hardware Input Please: Mobile, Self-Contained XBMC

[Dekx]

My goal is to build a self-contained XBMC unit to replace my daughter's portable DVD player. This is my first foray into RPi and electronics builds, so I don't want to do any soldering/splicing/etc. I want to have a single power cable coming out of the unit and I want some battery time so that the unit can persist when the car is off. I also want an additional HDMI out so that I can leave the touchscreen off and run the unit to a TV. In the future I can easily add a powered USB hub and laptop hard drive.

I just wanted to run my build by you all to make sure I'm not missing something, going overboard, using a less-than-optimal component, etc.

B+ kit

SainSmart 9" touch screen

HDMI Switch

Battery/Power Supply: I confirmed that it can receive and give a charge at the same time. This is the spot where I feel like should be able to save some money but I've scoured Amazon, New Egg and Tiger Direct to no avail.

Runs from power supply to touchscreen

Regards,
Josh

[Gomez]

You can definitely find a cheaper power bank.

It doesn't have to be this one but I do have a cheap power bank which also comes with aversatile usb cable which is nice.. I can use it with my Xperia and my brother uses it sometimes and it works fine with his iPhone so the cable can do the job and the power bank itself is good.

I am still waiting on my RPi from ebay so I am not sure if it works with it but I am pretty sure it does since the first port runs at 5V 1A (max) and the second port at 5V 2.1A(max), the first one should be enough amperage for a RPi without much stuff plugged into the usb ports ...

It's your choice on the powerbank, if you go for a reliable and trust worthy brand one or a cheap one out of ebay, it does do job for me but its your choice..

other than that you seem to have everything set for the project, good luck and have fun

edit:
it doesn't come with the charger for the battery itself.. I have this one

[Dekx]

Thanks! I found a cheaper battery and USB > 5.5 x 2.1 for way less than my previous battery pick.

One thing I just realized I forgot is speakers. I can find all kinds of internal speakers but they're not wired to run from 3.5 audio jack, and I can find all kinds of external speakers which run on 3.5 but which aren't small. Any ideas?

Edit: I'd prefer not to have to power them.

Regards,
Josh

[DougieLawson]

Edit: I'd prefer not to have to power them.

You don't have a choice. The analog audio from your RPi is line level only, you have to have an op-amp between that and your speakers and that op-amp will need power (admittedly you could power it from the 3V3 or 5V0 supply on the RPi's pins).

[Dekx]

That makes sense. It also makes dredging through Amazon much less painful.

Thanks!
Josh