To Land Yacht. Upon further reading, I have discovered that a 17F morning on a battery is a great way to introduce a LOT of internal charging resistance to a led acid battery. Of course, what happens then is that the battery I am using that 150 amp hour T-1275, becomes capable initially, especially with voltage drop at such temperatures, of sucking huge amounts of amps at start up. All that battery resistance doesn't help. What it does probably do is use the additional amps to make the electrolyte and plates heat quickly, so that things will charge properly with the electrolyte in the battery.
What this means is that my Mega Watt may have escaped going poof this time, and that these power supply units do NOT have a method of temperature compensation at extreme temperature ranges.
I had no way of knowing or predicting that I would be there in MT on the coldest day on record ever for a Sept 11th, when I turned the Mega Watt on that morning at 17 F.
Frankly, it really kind of sucked being in such temps in a 3 season Travel Trailer... I didn't get running water until 12:30 pm that after noon also.
My guess is that power supply units work a lot better in moderate temperature ranges... shirt and pant weather, but G string bikini or Carrhart insulated clothing weather temps, you need to reassess suitability and voltage you set at.
My other thought is that the Mega Watt I have may have a limit as to Amp hours and Batteries in your bank. It' fine with a pair of Group 24's, probably a pair of Group 27's also. I would test for bulk charging on a pair of 6V GC-2's to make certain that at a 50% SOC, they do not over draw or over load a Mega Watt S35 version, for bulk charging purposes, or back the start voltage down, pre hooked up, to 14.4V.
The Upper limit of Amp Hours in your battery pack needs to be defined for the Mega Watt. A single T-1275 may or may not be close to it with it's 150 amp hour capacity, and 75 amp hours @ 50% SOC.
YMMV... but as Mex says... when it comes to using power supplies, think before you do, and you'd better read a lot here and learn to understand some theories, if you don't have the EE title hanging from your shingle. I don't have that "EE status", so I rely on the Pro's from Dover here on this board.
