The mAH rating of a battery tells how much power a battery can deliver, but it's
measured at a particular current drain. I can think of two major ways a cell
might be "improved" while retaining the same overall mAH rating:
1) Ability to deliver more current (lower internal resistance.) The
maximum current that a battery can deliver is limitted by the battery's
internal resistance. While this seldom comes up for
flashlight people, people driving radio control electric motors
would like to be able to draw 20A or more from their battery packs,
even if that means it only runs for 1/10 hour. Not all batteries
can do that without hurting themselves. Some batteries can't do
it at all.
2) More capacity at higher currents. The mAH rating is usually done
at a current of C/10 or less (200mA for your 2000mAh batteries.) If
you draw more current, the battery will typically provide less overall
power (say, only 1500mAH at 2A discharge, etc.) You can improve the
battery by providing closer to rated power at higher currents.
Then there are more mundane improvements, such as more recharge cycles,
or faster recharging...
(someone has to read a detail spec sheet pretty carefully to figure
out what is going on, though...)
BillW
