kully560 said:
>>SNIP<<today another rep suggest a 40lb. tm sop as not to kill the battery for a day of fishing.
First off, are you running all electric? Or, do you spend most of the day using the TM or a lot of casting dead in the water? Alot depends on how you use the TM.
Anyway, I've read that
larger thrust motors at slower settings (which I bet most use most of the time) actually use
LESS current than a lower rated thrust motor at the same speed / amount of thrust applied.
That said, my 50 lb TM on my all electric boat and I will get four + hours run time (drained to 11.9 volts or 40% DOD) on a single tiny 35Ah solar / wheel chair battery, and I have three. The second is spare in case I run over 4 hours on the first, in the event I run over 8 hours which is very doubtful I can use the third "house" battery as my spare tank. I'm also conservative on the DOD even though my batteries are deep cycle and could drain them down further.
When I got my boat, I could (and did) run my boat all day on my Waaayyy too big and heavy 92Ah battery with power left to spare at the dock. Considering I'm running all electric, I seriously doubt run time will be an issue with the 55lb. the first sales man recommended.
Obviously some of this depends on your boat configuration. If you're running a gas motor and need to lots of starts on it with one battery for it and the TM, and the age / Ah rating of a single battery, or if you're running second separate TM battery and or a house battery.
Food for thought...
I setup a "house" battery for my DF, lights, and electronics because goosing the TM would drop the DC on the TM battery enough to reset the DF and GPS. A house battery fixed that.
I'm running THREE 35Ah batteries for a total of 105 Ah at ~65 lbs and they're easier to distribute weight, and it gives me backup should one battery fail. My old setup was a 92 Ah TM battery AND a single 35Ah house battery and weighed 85 pounds.
I'm on season three with this setup and it's worked out very well, the last thing I think about is TM / battery issues.