JimboZA:
Ok, here's an interesting twist on this- I happened to find an old (1997) RS catalog today while looking for something else. Seems they used to sell a battery checker (I can't find it online in their current (haha) offering, but it had the SKU 596-034), and according to the catalog this tests a 1.5V cell under a load at 35mA.That's an order of magnitude different from fungus' suggestion of 250mA.... anybody got any thoughts?
I invented my 250 mA number up based on the mAH capacity of a battery. I figured that a load that took several hours to discharge a battery would be about right. An AA should last about 8 hours at that load, an AAA about 4.
35mA seems tiny. An AAA battery with 2000 mAH capacity would take 2.4 days to discharge at that load.
Yes, a C or D cell would need a higher load to give a useful value. That's what I meant when I said "...depends on their size".