[patrick_g]

Yes, Mike, 'twas brillig and the slithey tothes did gyre and gimbal.

Thomas, What set my alarm off was the 450 AH comment. Again, I'm not super familiar with jump paks but when reading about them I did not see other battery technology mentioned beside lead acid. The ones I read about are lead acid technology with gelled electrolyte (gel cells). They have the energy density of automotive type starting batteries. A 450 AH unit would have to weigh over 4 times as much as the 100 AH batts in my truck and would not be the most convenient thing to carry around and would likely have to have wheels if not a little motor to help propell them (but at the prices quoted would have been a terrific bargain most likely to be preferred over "standard" automotive batteries.)

You may have indeed seen a 450 AH label or a misprint in the instructions. It wouldn't be the first time a product was mislabeled or misleadingly labeled. It just didn't pass my first stage sanity test, the too good to be true clause. If you could get 450 AH in that small of a package at that light of a weight for that cost, electric cars and or hybrids would get a serious boost in capability with a simultaneous reduction in cost.

My understanding of lead acid technology leads me to say:

1. brief high amp outputs for starting a diesel or gas engine is a reasonable use of the jump pak

2. Longer term but really light loads such as a trouble light, miniature air compressor or similar are OK if not continued till the batt is too flat.

3. High current loads like your winch, continued till the batt is exhausted or nearly so is NOT conducive to long batt life and not recommended use.

I didn't see any reference to other batt technology but it is possible that some jump paks may have other technology and be more forgiving regarding running them way down and recharging without damage.

When I use my 12,000 lb Warn winch for any non-trivial pull I leave the engine running to assist my parallel pair of 105 AH batts.

Pat