question

[abishop]

Does anyone know the formula on how to compute how long a battery will last if it has 195 reserve  pulling a trolling motor 100 percent with 55 foot pounds? This is a 12 volt system. I know the 195 cant mean the minutes at 100 percent. Maybe about 50 percent for this long. Just trying to figure on what size batteries I need to get for the amount of fishing time I need on each trip. TY

[RoeBoat]

It's dependent on the amp hr rating of the battery and the amp draw of the motor.  Both pieces of info are missing.

[RoeBoat]

https://www.trollingmotors.net/trolling-motor-run-time

Check this out

[izzy65]

Buy a good deep cycle batt and don't worry.

[bigr]

A couple paddles are always a good thing to have and a couple young boys to use them. A real good battery over a no name brand isn't that much more in cost but will be worth it. When you use a rechargeable battery(deep cycle) the best thing for it is to run it completely down. It will take and hold a charge much better and your batter will last longer.

[Oldbear]

I carry a spare battery when I'm fishing all day or hook them up in parallel.  Thats on a 16' old heavy Lund with a Minn Kota 55 lb. had 2 of them and  with hopping around brush pile fishing.  I've always been dissapointed in my run time per trip.  Tried a Motor Guide 55lb with a maximizer and had a little longer run time but it had 6 new control heads put on under warranty then I gave up on it.  Always recharge your deep cycle batteries at the end of the trip.  Anything motor bigger will be in 24 volt which will run you all day and then some.

[wax_worm]

When you use a rechargeable battery(deep cycle) the best thing for it is to run it completely down. It will take and hold a charge much better and your batter will last longer.

This is 100% inaccurate and a quick way to ruin a deep cycle battery.  The best way to damage a flooded lead deep cycle battery (not AGM or lithium) is to completely deplete it.  It is recommended they not be depleted below 20% and the higher end batteries have protection in them to prevent them from being fully depleted.  If new, the first 30 cycles(use, charge) or so should not deplete it below halfway if you want the most longevity out of your batteries.  Nearly every battery manufacturer out there has a webpage and list of do's and don'ts for batteries, and fully depleting one is a no no, listed everywhere.

[bigr]

Wax, Completely was the wrong word. I do suggest for warranty purposes you should follow instructions. My information came directly from vice president of one of the leaders in battery production. There company produces batteries for many lesser known brands. I trust what he's suggested to me. For my 60 month battery that has been cycled 100s of times for the best recharge i run it down most times below 10%(not dead/completely) and recharge right after use, never leave sit with that low charge. If I don't use it much leaving lets say 60 to 70%, The next trip I use the rest up so I can give it a full slow recharge. According to my fishing buddy VP short partial charges are not as good as slow full recharge. A 60 month battery that has had more slow full recharges is more likely to reach it's warranty than one with more short recharges.

[wax_worm]

Wax, Completely was the wrong word. I do suggest for warranty purposes you should follow instructions. My information came directly from vice president of one of the leaders in battery production. There company produces batteries for many lesser known brands. I trust what he's suggested to me. For my 60 month battery that has been cycled 100s of times for the best recharge i run it down most times below 10%(not dead/completely) and recharge right after use, never leave sit with that low charge. If I don't use it much leaving lets say 60 to 70%, The next trip I use the rest up so I can give it a full slow recharge. According to my fishing buddy VP short partial charges are not as good as slow full recharge. A 60 month battery that has had more slow full recharges is more likely to reach it's warranty than one with more short recharges.

Yes there is a big difference between completely drained and down to 10 to 20%.  Thanks for clarifying you did not mean run it dead.

[Stinkybaits]

I had a small issue with power three deep cycle all state green batteries. Granted they were probably plenty of power for one fish finder and a trolling motor but when I added a few goodies power was a problem. This was solved by 4 lithium batteries that were costly but there's zero power issues. Only problem I had was when one cell wasn't working on the charging system so one battery wasn't being charged and the trolling motor just stopped. Well with a Trevora it's all auto and the manual requires disassembly. Thank goodness there was good cell reception and Minkota sent me the quick guide with pictures for dummies so we got it up. Love the lithiums but they go at full power until the very end then nothing. I'm having a switch installed so banks can be changed if needed to for power.

[bottom bouncer]

After fighting with under powered 12 volt trolling motors for years on all my boats. Quite a few years back I  dropped some serious coin (for the times) and bought a 24 volt trolling motor for my 17' Sylvan. After years of struggling with batteries going dead in the breeze or current and not enough oomph to move the boat when you needed it, a 24 volt troller was like a dream come true.  Run all day on a windy walleye lake or in a river and still have power for a mornings fish on a set of cheap BPS wet cells.
I've reached an age where I think the big ol' Sylvan with the 115 needs to heaven forbid, be put up for sale and downsize to an easier boat for this old man to handle but one thing's for sure whatever I get it'll have 24 volts on the bow