Re: Dual Battery - YES!!!
I installed a second battery in my rig with components that I found at the local auto parts store & a dual battery isolator/dash indicator on EBay (Vortex Brand ≈ $125).
The dual battery isolator kit came with the solenoid, cables, and most importantly - a display to mount inside the cab that indicates each battery's strength. It also has the capability to toggle between batteries, so if the primary battery is dead, I can "jump start" myself via battery #2. Or if I need some extra OOMMPFF, they can be tied together (such as when the wench is under a lot of load). Come on, doesn't your wife get out & push when you're stuck?
To make room for the second battery, I removed the OEM air cleaner box & installed a "free flow" aftermarket air filter. The filter now, turns down & tucks neatly in front of the brake master cylinder.
I installed a plastic battery tray (corrosion) in the space where the air box was. The battery tray required some leveling, so I leveled it with some SS bolts that pass through the inner fender wall. I used some nuts, fender washers & lock washers to hold the tray at the right height.
An auxiliary fuse box was installed on the inner fender wall below the master cylinder, to feed all of the new components. an 8 Ga wire feeds a small fuse panel under the rear seat. The winch has her own dedicated cables. The ground for the winch & battery #2 are tied to a dual copper grounding lug on the chassis below battery tray #2 (Home Depot electrical department). There was enough spare cable between the winch & the dual battery kit to even upgrade the OEM battery, battery and fuse box grounds, & positive alternator output cable.
There are some additional relays to control auxiliary lighting, power sockets, and a power converter under the rear seat - driver side. I installed some power sockets (under front drivers seat & under rear seat on the face of the kick panel), to power spotlights, & recharge stuff. They are fed from battery #2, so that the main is not drained to power a cooler, tv, radio, space heater, etc.
Spiral wound batteries was used for both batteries, as they can be installed on their side without any leaking. A hold down strap with j-hooks worked the best in keeping it in place. Battery #1 was a more expensive Optima, #2 an Exide.
As for all of the toggle switches, I found a great place for all of them - between the speedometer cluster & the AM/FM radio. I mounted them in a column & was able to get 6 of them into this location (F-Fogs, F-Driving, Roof-Driving, R-Flood, Brake lights, & a spare).
Yes, brake lights... I want to be able to turn them off when hunting [so we can sneak up on game or drive a ridgeline, without alerting the game (or snipers) when we brake]. There is a red led on the dash that lights up when the brakes are activated when this switch is in the "off mode."
Here are images of the installation. The foam "pre-filter" on the air cleaner is there because I do a lot of off-roading in dusty areas. I can easily remove & rinse the foam filter in any stream or faucet. It is merely a foam "pre-filter" from a shop vacuum. It is pulled back to illustrate the filter underneath.
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