johnny it wasnt a negative comment, just that if you leave them on you will get shorter battery life.. if you measure the system in use the meg draws alot more current than the HH electronics.. Duration depends on the batteries and how much the solenoid and backlight is used.. and we all know that most meg divers fly their units manually (because of training) while most HH electronics users don't..

come one.. 3 hours is a safety suggestion so that you always have power in reserve and to try and cover duff cells out of the box.. Normally in warm water you can expect 6 hours+ out of a single AA (more if you fly manually).. if you compared that to 5 aa cells for the meg thats over 30 hours... Alkaline cells on a meg are more resistant to cold water because the batteries are in the loop and will be warmer than ambient water temperature..

I use 3.6v cells and on my last set I had OVER 40 hours (4 full CCR classes plus pleasure dives) of dive time (it was a mix of automatic and manual).. I don;t know the exact time since it was spread out over 3 different heads.. before the monitor and if I didn't have a vm handy, I would replace the cell between 15-20 hours of dive time (not bad for a $5 battery).. if I could test them I used them longer..