I have had very good luck with my Moor Sub Troll 900 speed and temp unit. This year I started having problems. I checked the battery and replaced it several times. It worked then quit. I switched from the CVS battery to a Duracell and problem solved. The clips on the terminals were loosing up on the CVS. The Duracell had a more positive snap and works. Hope no one got frustrated with these units because of the battery.