Next time the battery in an H3 Hummer dies, I recommend getting the Optima Battery 8022-091 75/25 Red Top or 8042-218 D75/25 Yellow Top instead of a factory replacement. Although, the Optima D75/25 is much bigger than the factory battery and will not fit inside that plastic box… I think to myself “Do I really need that battery box?” Personally, I think that plastic box is just there to add a distraction from how small the battery is and the non-GM labeling of the battery. I ditched that H3 Hummer plastic box that was hiding the small battery and dropped in a much bigger battery in its place. Reason being, the factory battery is underpowered for a winch and provides only a single set of terminals.
My Warn M-8,000lb winch is capable of such extreme power demands that it can easily damage a battery. The alternator will never be capable of keeping up with the demands either. Throttling the engine of H3 Hummer up to 2,500 RPMs helps out with those demands, but again it will not keep up. However, a bigger battery is just a better all-around solution, just don’t forget to throttle up when winching. The Optima D75/25 has ~33% more power over the factory battery that GM decided to install. That ~33% more power goes a long way helping smoothing out the issues of winching.
The Optima D75/25 battery has the added benefit of having dual terminals ready to go. I use the Traditional style connections posts on top for the H3 Hummer factory wiring harness. As for the side terminal battery screw posts, I have my winch all by it’s lonesome. This is also where I would wire up things like hi powered lights, compressor, portable fridge, and other hi demand electronics. Having the Winch and the ECU, HVAC, Stereo, etc. on a separate post from the winch is a better setup. This way the winch isn’t trying to pull excessive power through the same point of contact that the Hummer is trying to run on and charge. Also with the winch and the vehicle’s electronics further isolated from each other, in theory, this should help maintain a healthier battery.
Considering this is a Hummer, I doubt I’ll ever agree with why GM put such a small battery in the vehicle designed for going off-road or that pointless battery box in there. However, the engineers at GM truly did us a true spirited 4×4 enthusiast a solid favor by making it so easy to install an Optima D75/25 battery in its place. Of course, don’t forget the aesthetics, because, with such a beautiful battery like that, it would be a shame to hide it in a plastic box.