jmo, but i can't be annoyed with manual batteries. i have an ego that i only use if my other batteries are totally dead. for total ease of use, go with an echo for longer battery life or volt/bloog for size. and, don't worry about folks telling you that you'll kill a battery. it takes very little care to fill a carto and just tap it to ensure no liquid is exiting the bottom. heck, the new auto volts have a sealed top anyway. regardless, the only battery i've killed(and this is tmi, be warned) was with an echo i was using with a plastic whistle dip while using the bathroom. standing there with the echo in my mouth while doing my business and it dropped off the whistle tip because of the weight and ended up in the loo. the whistle tip stayed in my mouth, so i still have that. 
