Originally Posted by cyccommute
Yes, for small batteries (low Ah rating) high current draw will shorten their life. For a detailed description go
here. For your pack, you are pulling 2.4A from a 5 Ah battery which means you are drawing about half the battery capacity per hour. This is actually a pretty comfortable amperage draw for a rechargeable. If you were using a 2.5 Ah battery, you'd be on the edge. If you were using AA batteries (1.3Ah), you'd be killing them in no time flat.
Heat, whether on charging or discharge, is the enemy of nearly all rechargeable batteries.
Actually, my current pack is 12 2.5Ah AA batteries, so I guess I'm on the edge. I think most AA rechargeables nowadays spec at at least 2 and often 2.5Ah (Energizer does).