These are long life but low current batteries. I was looking for batteries for my 40+ year old HP-11C calculator. There are lots of "compatible" batteries that would fit and work in the 11C, but the sliver oxide 357s can last up to 10 years in this calculator. The record is 20+ years. These may not test well on cheep battery tester. A cheep battery tester may put to high of a load on the battery causing it to test low. When my batteries came in I tested on a ZTS MBT-1 battery tester and all 3 tested at 100%. Another plus is the 3 pack, the calculator uses 3 batteries.