[HarryT]

Originally Posted by danskmacabre

Ah that's interesting.. I don't suppose you have any links detailing that?
Not that I don't believe you, just curious as to the reason behind that.

According to Wiki:

The internal resistance of standard (Cobalt) lithium-ion batteries is high compared to both other rechargeable chemistries such as nickel-metal hydride and nickel-cadmium, and LiFePO4 and lithium-polymer cells.[50] Internal resistance increases with both cycling and age.[51][52][53] Rising internal resistance causes the voltage at the terminals to drop under load, which reduces the maximum current draw. Eventually increasing resistance means that the battery can no longer operate for an adequate period.