Augment a pickup to be a power generator - electricity.straw.vehiclepower PEP BB

This is a badge bit (BB) that is part of the PEP curriculum.  Completing this BB is part of getting the straw badge in Electricity.

In this Badge Bit, you will augment a pickup or other rig to be a generator.  Instead of maintaining a generator to power your tools, why not use the engine in your car?  Let's add some batteries to your rig so it can stack some functions!

Here's a video of a pretty nice system:


And another that is also in-line with the aim of this BB (except for lacking one battery):


To complete this BB, the minimum requirements are:
  - has two batteries (not counting the vehicle's battery)
  - has fuses at both ends of the main supply wire
  - can provide AC and DC power
  - is a relatively permanent installation

To show you've completed this Badge Bit, provide proof of the following as pics or video (less than two minutes):
  - the parts you're putting together
  - a short description of the build
  - the project mid-way through
  - the assembled back-up battery system
  - the system powering a device