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Hummer H2For those who like a little more gleam to their Hummer, the H2 offers a similar rugged look as the H1, but as a lower cost, and with more added features, making it almost a massive luxury SUV.
Thinking of adding a winch, but I got a lot off stuff already on this battery, lights, air compressor, etc…
Im gonna put a deep cycle marine battery where the current battery is just to make hooking everything up easier. And I’m putting the starter battery on the passenger side where the expansion reservoir is.
I want to have everything in the truck work on the deep cycle and only have the starter battery work the starter. Very similar to what you might see in a marine application on a large boat. So basically with the key in acc mode, it’s only going to draw from the deep cycle, but when the truck is started, the starter and deep cycle are linked and charging off of the alternator. I’ll have a smart isolator that turns on at 13.3v and off at 12.8v to accomplish this…
My plan for the coolant reservoir is to use one from a 2015-2022 f150 and mount it above the electric fans. If anyone has a better battery mounting solution or coolant reservoir solution please let me know. Also tell me if my wiring schematic is terrible and going to break something…
Will there be an issue with having the ECU and starter on different batteries? Even if the batteries are only unlinked for a short time during cranking? Ideally I’d like to have the starting battery connected to the fuse box, but Id like to run the radio and stuff inside the truck with the engine off. And my air compressor and inverter are all on switched ignition power and everything is already wired.
Last edited by Gavin Costigan; Jan 1, 2023 at 09:01 PM.
Edit:
I also found this smart isolator on Amazon that I might use. Seems to have more documentation than the one in the original post. I like that it has a manual override too. But the other one has that as well.
I know the ones that are Duramax swapped put the second battery right up against the washer fluid reservoir remove the stock airbox is and just use a cone style filter on the end of the air tube. The biggest drawback to that though, which I am not fond of, is that basically turns it into a hot air intake since all intake air is then coming from under the hood which is not ideal but realistically it probably does not make much of a difference. Another option I've seen on some ambulances is they have a battery box mounted underneath to the frame. Heavy duty steel box and it does make changing or servicing that battery more of a pain in the butt. Google image search frame mounted battery box. Might be a decent option if you can find a spot big enough to mount one.
I'm looking at doing the same thing sometime this summer but on a different vehicle - I have a custom stretched S10 tow truck (yes a small S10 but it has a 1 ton dually axle with air suspension) with a 16 foot hydraulic tilt deck with a winch. Right now is just runs everything off the stock battery and the winch struggles if I'm trying to winch a vehicle on that is not running. On this I have plenty of room under the deck along the frame to mount a battery box so location is pretty easy for me. Pic of the S10 if you are curious....
I know the ones that are Duramax swapped put the second battery right up against the washer fluid reservoir remove the stock airbox is and just use a cone style filter on the end of the air tube. The biggest drawback to that though, which I am not fond of, is that basically turns it into a hot air intake since all intake air is then coming from under the hood which is not ideal but realistically it probably does not make much of a difference. Another option I've seen on some ambulances is they have a battery box mounted underneath to the frame. Heavy duty steel box and it does make changing or servicing that battery more of a pain in the butt. Google image search frame mounted battery box. Might be a decent option if you can find a spot big enough to mount one.
I'm looking at doing the same thing sometime this summer but on a different vehicle - I have a custom stretched S10 tow truck (yes a small S10 but it has a 1 ton dually axle with air suspension) with a 16 foot hydraulic tilt deck with a winch. Right now is just runs everything off the stock battery and the winch struggles if I'm trying to winch a vehicle on that is not running. On this I have plenty of room under the deck along the frame to mount a battery box so location is pretty easy for me. Pic of the S10 if you are curious....
S10 tow truck? That’s the first I’ve seen one of those! But I might just be too young. I might end up just doing a cone filter. Shame though since the H2s intake design is pretty cool.
Lol - you will never see another. The frame is custom stretched and the 1 ton dually axle is from a Toyota motorhome. The tilt deck is custom built...
I agree that the cone filter does seem like the easiest solution as eliminating the stock airbox frees up a nice big spot for a second battery.
I wish we had another section for general car related stuff, though that might defeat the purpose of having a hummer specific forum. But I’d love to see what your doing with that truck.
I’m going to look into maybe doing something with the washer fluid. Maybe I can fit the battery back there or the coolant res back there. And there are some smaller pump/res combos for $15 on Amazon I could mount elsewhere.
A cone filter might be more of a pain that it initially appears. I’d have to find an adapter that fits the MAF with enough clearance from the throttle body. And on top of that, the supercharger noise is already pretty loud.
maybe you can go with a LiFePO4 battery you can probably get a smaller battery that way since they hold twice the energy for there size as a regular battery. might be simpler to relocate.
Dual Battery Upgrade
