Help me with trolling motor/battery selection

[JN94]

Rookie boat owner here. I've got a 17' aluminum Tracker that I want to make a few upgrades to. One is to buy a Power Pole Move trolling motor and upgrade to a 24v LiFePO4 battery for it. I keep reading conflicting things regarding how many AH I should be looking for. I read some things that say a 50AH will run a trolling motor "all day" and some that say 50AH will only last "a few hours". Some people have also noted that it depends on how much thrust the TM puts out. PP says the Move will put out 78lbs of thrust. Can someone help me understand here? If I were to buy a 50AH battery, how much run time can I expect out of my TM in average conditions?

[MN Fisher]

Need to know the AMPs the TM uses.

 

Example: A Minn Kota 30 uses 5 amps at setting 1 and 30 amps at setting 5

So a 50ah battery will run that Minn Kota 30 for 10 hours at setting 1 and 1.66 hours at setting 5....so an entire day of fishing will be somewhere between that as you'll use different settings for different conditions.

 

[JN94]

16 minutes ago, MN Fisher said:

Need to know the AMPs the TM uses.

 

Example: A Minn Kota 30 uses 5 amps at setting 1 and 30 amps at setting 5

So a 50ah battery will run that Minn Kota 30 for 10 hours at setting 1 and 1.66 hours at setting 5....so an entire day of fishing will be somewhere between that as you'll use different settings for different conditions.

 

Where do I find that info? I don't see it skimming thru their website 

[MN Fisher]

16 minutes ago, JNorman said:

Where do I find that info? I don't see it skimming thru their website 

Dive into the manual for the TM...they should at least have Max Draw in AMPs somewhere.

[casts_by_fly]

page 43 in the manual gives a chart of thrust level vs current draw at each setting.  On full power 78 lb thrust its pulling 48 amps.  That's not so bad considering my 43 lb at full blast is pulling around 40.  That said, if you were using the trolling motor for your only propulsion and running on full speed you'd only get an hour out of it.

 

In practice, it will depend on what type of motor user you are.  I assume you have a gas motor to get spot to spot.  In that case you're more likely going to be on half power or less on the trolling motor most of the time as you go down the bank or lock into a spot.  At level 10 (out of 17 for the 78 lb thrust) you're getting 25 lb of thrust for 9 amps.  That would be like 5 hours of steady use (running down the bank with a moving bait for instance) and you'll probably be going faster than you want to on that speed setting.  If you're more like a bump it on and off type of fisherman (like most) then you'll get plenty of time out of a 50 ah.  Fishing rivers and tides would change the equation a bit.

[Tennessee Boy]

Very few people would power that trolling motor with one battery.   Most want enough power to get them through the most demanding day.  50 ah would be fine for almost all of my trips but I want enough to cover 100% of my trips not 95%.  Also it’s always good to have enough to get you somewhere if your outboard has problems.  Unless you have a good reason for wanting to go with one battery,  I would encourage you to get two.   If the cost of a second LifePo4 is a problem I would go with traditional lead acid.  Remember your 50ah battery will start losing capacity on day one.  In a few years it will be a 40ah battery and someday a 25 ah battery.  LifePo4 batteries last much longer but they still lose capacity with use.
 

[JN94]

2 hours ago, Tennessee Boy said:

Very few people would power that trolling motor with one battery.   Most want enough power to get them through the most demanding day.  50 ah would be fine for almost all of my trips but I want enough to cover 100% of my trips not 95%.  Also it’s always good to have enough to get you somewhere if you’re outboard has problems.  Unless you have a good reason for wanting to go with one battery,  I would encourage you to get two.   If the cost of a second LifePo4 is a problem I would go with traditional lead acid.  Remember your 50ah battery will start losing capacity on day one.  In a few years it will be a 40ah battery and someday a 25 ah battery.  LifePo4 batteries last much longer but they still lose capacity with use.
 

I would do multiple/larger AH but space is my issue. My battery compartment is built for two group 24s. Maybe could squeeze a 31 in there but I think it would be super tight or maybe not fit at all. I haven't measured it to confirm