Re: Variable speed motors~just how much longer does the battery last?
ooops stepped away and this thread jumped ahead...
With all other things being equal (are they ever?) the answer would be yes. Are we talking two or three times as efficent? No, afraid not. More in the 10% to 15% range for most applications.]
Under normal conditions of trolling at mid range speeds, digital TM's are
at least 2-3 times more efficient as an ol' school speed coil TM's. Been there, done that, have the Tshirt to prove it. This is from a real world prospective of using them. I've used a Traxxis, at least 2-3 times longer run time. Used a Varimax, 2-3 longer run times. Heck, I really don't know how long the battery lasted with a digital TM as I never ran down the battery completely dead, 10 hours of fishing and it was still kicking. With a 5-speed TM, the battery would be toast in 4-5 hours.
{edit} If this were a high quality stepper motor that had to maintain precision speed and hold position at low speeds I'd agree with you as it would take more power to control the motor. A stepper motor that's is stopped is eating up current holding position of the motor, something a trolling motor doesn't have to do. A Digital TM's circuitry is pretty crude, compared to a stepper motor controller. Designed along the lines of efficiency opposed to accuracy. {end of edit
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And that's why I think the claims of 4-5 times the battery life are really only with the absolute ideal conditions.
I'll will agree with that and think 4-5 longer is a stretch.
BUT, (and this is not ideal conditions, overkill if anything) I put a 24V 70# digital TM on my jon boat to see how it would do. After 12+- hours of trolling the 2 batteries were still 75% charged. The old 40# Endura would have drained both of those batteries in 8-10 hours. Yeah, I agree that not many will experience this type of result as I was running the 70# TM really slow. But it goes to show that digital TM's can be very efficient.
It's just not the improved battery effiency, a digital TM is a much better tool for trolling. Let's say you are bucking the wind and trying to pull your lures at 1.5 MPH. Going up hill (against the wind) the digital will allow you to "dial-in" and bump up to the perfect speed, going down hill the digital TM will allow you to "dial-in" and slow down to the perfect speed. 5-speed motors have fixed speeds, and from what I've experienced, finding the "sweet spot" is hit and miss, #2 too slow, #3 too fast, etc.
I can defiantely understand the money thing and think digital TM's are pretty darn pricey. If you are only going out for 4 hours at a shot, you won't see a huge benefit of getting a digital TM, outside of the variable speed.
(BTW, you are going to hate me for this... BPS had the old model Varimax 40# TM's on blowout special for $125 a couple weeks ago. Even though I don't like this TM, I was really debating on buying one. $125 for a digital TM
I'd put up with the annoyances for that price! Too bad they only lasted for a couple days. You might look around and see if you can find another place blowing them out as MG redesigned several annoying "features" of the Varimax and the new models are going for $250+. For $250 I'd pay the premium and get a Minn Kota)
