Lowrance 2000C battery life
<For example, Lowrance 2000, good though it is, only seems to have two hours battery life>
Only about an hour on alkalines, assuming you press the button every minute or so to get the display visible again. It really needs to be powered via the cigar lighter.
Otherwise it seems great and excellent value. Comes with 3 different mounting systems. There is a simulator on their web site which is very useful to try before you buy.