You can wire it to an ignition source,carefully.
Pull the headlamp fuse, and use a volt meter to see what terminal has power
with the lights on. NOTE that, and stay away from it.
Wire a fused jumper to the adjacent terminal, then the other end to the switched
You will cut one spade terminal at the end off, and that goes to the
+12 ignition. Then the other spade terminal goes into the fuse slot
that does NOT have power on it with the lamps on.
It will go like this:
Notice the red fused jumper. This will take the power from the left lead,
and sent it to the fuse terminal on the right lead. You would do the same
thing. If the wire will not stay in that terminal, plug a blown fuse in over
top of it, like this:
This was how I changed the switched 12V Ports, to 12V battery so they were always hot.
This was also how I wired an AUX battery to all my audio components in a
different car. That way, my 1800 watts of stereo would never drain the
primary battery, to never have a starting issue.
The batteries were separated by an isolated relay. That relay was only latched
when the key was in the RUN position, to charge both batteries. So, if the AUX
battery was weak, it would not pull any power from the primary when cranking.
Thus, when the key was in ACCY position so I could use the stereo, they were
still separated. I wired the amps, radio, and some lighting to the AUX battery.
Had two LED volt meters, one on the primary, and one on the secondary. The
secondary also had a solar charger on it, set on the rear deck, in the back window.