Hi Flying Fish.
I have Minn Kota and when I first got it I used the type of charge that you have.
I didn't like it very much.
When I have a chance to fish I fish a lot. The charger that I had would take 10 to 14 hours to charge me battery which meant that as soon as I got home the charger went on-and some times I would go back out with a battery only 75% charged.
I now have an Schumacher SC-8000A - 80 amp 30<>12 amp , 2 amp with Engine Start charger. I can charger both battery in about 6 hours.
I got mine from Bi-Mart for $83.
Fully Automatic Microprocessor Controlled
• 80 Amp Engine Start – for emergency starting.
• 12<>30 Amp Fast Charge - self-adjusting, variable charge rates for everyday charging needs and maintaining your battery in peak condition. Charges and automatically desulfates and restores car, truck, RV, farm equipment, AGM, gel cell and deep-cycle batteries.
• 2 Amp Slow Charge – for charging and maintaining small batteries; charges motorcycle, ATV, snowmobile and lawn tractor batteries.
• 125 Amp, Sure-Grip Clamps – for top and side-mounted battery posts.
• Electronic Touch-Pad Controls – easy-to-select switches for Digital Display, Battery Type or Charge/Start. Choose from 12V regular automotive, 12V deep-cycle, 12V AGM or gel cell and 6V regular batteries.