I have a ES1224 Truck PAC that I have had for a year and a half, and I have only used it maybe twice for 24 volt, and eight or ten times for 12 volt. One of those times was to start my Dodge with a Cummins when it was 5 degrees outside and the truck would barely turn on lights, and the starter would not crank or even click. Plus, the Truck PAC was not in a heated area overnight. This PAC cranked the Cummins like it was 50 degrees outside easily!
I once again used this last week when it was 35 degrees out and I had a Cat 627 Earthmover (24V) and went to start it. It would only click and maybe bump the fan blade an inch or two, so I tried the ES1224 Truck PAC on it. Well, believe it or not, with some help from the starting fluid can this started right up, maybe not the fastest cranking, but hey, with basically no battery help, I was impressed here. This is quite a task for a 24V diesel in cool weather.
These are not cheap, and they are heavy to carry around, but this is the only brand to buy, and I would recommend it to anyone. So, don’t get like all other manufactures and cheapen stuff up. Keep up the good work on a great product.