After reasearhing how to install a UHF radio and second battery into a Isuzu 2022 MUX, I couldn't find any information on how to get the DC and UHF radio coaxial cables through the firewall, I searched forums and Youtube, there are many that show fitting to a DMax but not an MUX specifically so I decided to do a brief video on my installation, hopefully it will be a good guide and give you some ideas.

I reasearched all the parts for the second battery installation and decided to use the Itechworld equipment as it seems to be comprehensive and a good price.

I also decided to install the Victron SmarShunt 500A/50mv and the Victron Connect app, this will give me the state of charge of the battery, the capacity left, the current drain and charge voltage.

For the UHF radio I chose the GME 330C radio, mainly for its compact size. The antenna is AE4018BK1 for its flexibility and cheapness of any failure in the antenna itself, I also chose for the 2.2dBi antenna the AE4002 again for its flexibily and ease of replacement.

Here are the links to all the equipment.

Itechworld
Battery: https://itechworld.com.au/collections...
Solar Blanket: https://itechworld.com.au/collections...
DC Control Hub: https://itechworld.com.au/collections...
25A DC-DC Charger: https://itechworld.com.au/collections...

Victron
Victron Connect App: https://www.victronenergy.com.au/pane...
SmartShunt: https://www.victronenergy.com.au/mete...

GME
XRS-330c Radio: https://www.gme.net.au/au/fixed-mount...
AE4018bk1 6.6dBi Antenna: https://www.gme.net.au/au/antennas/ae...
AE4002 2.2dBi Antenna: https://www.gme.net.au/au/antennas/ae...
You can also connect to the UHF radio via the XRS Connect App