Ampere-hour is a unit of electric charge. One ampere-hour is the electric charge that flow in electrical circuit, when a current of 1 ampere is applied for 1 hour. 1Ah = 1A 1hour. One ampere-hour is equal to 3600 coulombs.
1 If your propane tank has been requalified, the requalification date will be printed on an oval sticker and affixed to the collar of the tank. 2  If the date on the sticker does not have a letter to the right of it, your propane tank needs to be requalified within 12 years of the date on the sticker.nstructions. Locate the collar of your propane tank. The collar is the raised piece of metal at the top of the tank, surrounding the valve. On the bottom half of the collar, look for the letters MFG DATE.. This indicates the manufacturing date.
I've found that a 20 lb. tank of propane lasts about 23 hours of furnace usage.....yes, I made a chart and kept track of the run times! I have a propane fireplace at home which is the same BTU, and it too will drain a 20 lb. tank in about 23 hours of usage.Logged. lb of propane per hour of furnace run time is a good estimate. BTU per Lb. of Propane Gas 21,500. A 20lb propane tank might only have 15 lbs in it! If you set the thermostat low it lasts longer, 50F ain't is not that cold.