well a 2500 should last longer.. on the same load.. but it should also take longer to charge..
1200mah (mah = milli amp hours..) if your truck draws 200mah then the pack should last 6 hours and if your charging with a 100 mah charger it should take 12 hours to charge..
the 2500 pack should last 12.5 hours on a 200 mah load.. and take 25 hours to recharge on a 100 mah charger.. (100 mah charger is used for comparison.. that is the size of the charger that came with the packs i ordered, a peak charger will do this alot faster and is better for the battery pack..)