Here is picture of an older and larger battery pack. This one has a 33 AH, SLA battery in it and is charged by a separate SLA charger/maintainer. It does have a voltmeter in the case lid that is powered only when the switch to the right of the meter is thrown.
This shot of the interior shows the battery and charger (lower right hand corner). The external 110 AC power cord for the charger is stored on the left end of the battery
To the right is a picture of the newest battery package. It contains a 12 AH, 12 VDC, SLA battery that I obtained from an on-line supplier. The carrying case itself was purchased from a local store of a national tool retailer. The photos below will provide more details and a separate 33AH unit.
N1GY- The simple Approach to Ham Radio
A Couple of Homebrewed Battery Packages
Here is the power cord laid on top of the battery case. Because it .is only a 2 conductor unit and is not position restricted, I used a simple 2 contact set of Powerpoles to connect the external cord to the internal wiring to the charger. It connects to the Powerpole set marked AC Only at the lower left side of the top.