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.
3. Be sure to weight the tank. The tank should be weighed to get credit for the propane that still exists in the bottle and to prevent from over filling. To find the weight of your tank look for the letters TW stamped at the top of your tank followed by a number.. Inspect the cylinder. Before filling any propane tank there must be a proper visual inspection of the cylinder. Look for any damages such as deep dents or areas of heavy rust. Look around the fitting on top of the tank to make sure it is not bent or damaged in any way. Inspect the nozzle for obstruction.