Experiences with Minn Kota DC chargers?

[MSKYHNR]

anyone use the DC chargers from Minn Kota that charge your batteries from the big motor on long runs? how well do they work? any idea how much run time it takes to charge the TM batteries for another hour of use...ie, 10 minutes run time adds how much life to a couple TM batteries on avg?
thanks for any help or input/info
bn

[3M TA3]

Originally Posted by MSKYHNR

anyone use the DC chargers from Minn Kota that charge your batteries from the big motor on long runs? how well do they work? any idea how much run time it takes to charge the TM batteries for another hour of use...ie, 10 minutes run time adds how much life to a couple TM batteries on avg?
thanks for any help or input/info
bn

I just installed one. Heading to Ontario for 2 weeks in the bush. Alternator output is key. The faster your main runs the more current it puts out, the faster your batteries will charge. That's if you starting battery is up to snuff though. I'll let you know when I get back.

[point12]

I've had one in my boat for a couple of years now. Love it.
I would never have a boat without one again.

Al Denninger

[3M TA3]

Used it while in Ontario. Main motor was run only about 30 to 40 minutes each day. It definitely helped keep the
TM batteries charged however I think you would need to run main for several hours each day if you used the TM a bunch. Regardless, it helped for sure and I'm glad I made the purchase and installed it.

[montanafos]

I was going to purchase one for my boat and after talking with the manufacturer about it they pretty well convinced me that it wasn't going to de me much good in my application. Which was...fishing on lakes with no electricity where I would be using my bow mount trolling motor frequently. The best solution ended up being a yamaha 2000 watt generator. That has been a PERFECT fix. Can use it for the camper and the boat and if the boat is in the water I can set it in the bow and charge the batteries.

About how much more run time do you estimate it gives your X (number of Volts from trolling motor)?

Sounds like i might get one of those myself.

[REW]

The real problem with using the main motor alternator to charge your trolling motor is that you simply don't get enough out of your main motor to give you the added boost to your trolling motor in a reasonable amount of time.

If you are running your trolling motor on high, you are discharging your trolling motor at about 20-40 amps.

Most of the big main motors today, have a "surplus" alternator current available in the amount of 10-15 amps. So, lets assume that for practical purposes, you can recharge your trolling motor batteries at a rate of 10 amps which might be close for many motors. Remember, in many of the fuel injected and or other new motors, the alternator can be a 30-50 or even a 90 amp alternator. But, if the engine is fuel injected, the fuel pump will often require 80-90% of the available alternator current to keep the fuel flowing to the engine. So, even though you might have a pretty large alternator on the boat, this does not mean that you have much spare current available for use off of the motor.

But, if you can charge your battery at a rate of 10 amps, and you have run your trolling motor in the wind and waves on a speed of 10 out of 10 or maximum power, for 6 hours of fishing --- you will then need to run your big motor for 12 hours at least 1/3rd throttle or an rpm of about 3000 rpm to get the batteries charged back up.

Every situation is different. Maybe you have a 100 amp alternator on your big motor that has a 90 amp surplus when the motor is running. Not likely but possible. Then, if you could charge your battery at 90 amps, you could recharge that same battery that you used for 6 hours at 20 amps in about 30 minutes of running your big engine.

So, if you are on a big lake and if you normally run your big motor for an hour going to the fishing ground and another hour on the way back for 3 or 4 hours of fishing with the trolling motor at partial power setting, you could likely get some of the trolling motor batteries recharged.

But, as the other posters have suggested, the best solution is a small gas powered generator that you can run at night or in the evenings after you have returned to camp. Simple easy and absolutely reliable.

Take care
REW

[3M TA3]

REW, you make some good points. I will say however that my two bank alternator charger got me 2 extra days of TM use on my last 2 week trip in the Ontario Bush. I really didn't know what to expect from the charger and I have no clue how much current my alternator had to spare. I do know that the charger cost less than 100 bucks including shipping. Not sure if I would have had enough room to take along a small generator and extra gas for it since the boat was loaded super heavy with 2 weeks worth of food and camping gear for 3. All I know for sure is that I ran the TM pretty much the way I've always run it, speed of boat at around .8 to .9 mph and I got 2 extra days out of the batteries. I thought it was a good deal for my type of use and so far, it has served me well. My main engine is a Honda 150 and I also have the Honda 9.9 for those windy days and I will admit to the kicker use during the trip as well. Perhaps 30% of the time. Same as previous years.

Catch some fish.

[3M TA3]

I meant to add that I would not have enjoyed the sound of a generator disturbing my peace after a long day of fishing. The quiet is one of the best things about going up there.