Trolling motor battery - SLA, Lith Iron, ?

[Slackdaddy]

Putting a 36# minn Kota trolling motor on my Jackson coosa, for use in the PAX river.
This will be used to GET me to my creeks I fish off the PAX, not all day fishing.
Max will be 2 miles each way, but most are in the 1 mile each way.

How do you determine run time under Wide open throttle for a 36# trolling motor
I was looking at a 12v 50ah battery, that should be more than enough ??

So,
A 12v 50ah SLA battery is $100 shipped and 30 pounds.
a 12v 50ah Lithium Iron battery is $450 and 15 pounds.

While I would love a Lithium battery, I cant see spending an additional $350 to save 15 pounds??

I need words of wisdom,

Slack

[nhunter344]

Where do you launch? How far will you have to carry the battery to the launch? If its close, then I dont see an issue with the SLA. If you're walking a hundred yards each way, I would give more serious thought to the LiFePo4 battery.

[Slackdaddy]

I have 3 main launches I use over a 8 mile stretch of the PAX, I am parked and unloading max 25' from the water.

[FishnFun]

Putting a 36# minn Kota trolling motor on my Jackson coosa, for use in the PAX river.
This will be used to GET me to my creeks I fish off the PAX, not all day fishing.
Max will be 2 miles each way, but most are in the 1 mile each way.

How do you determine run time under Wide open throttle for a 36# trolling motor
I was looking at a 12v 50ah battery, that should be more than enough ??

So,
A 12v 50ah SLA battery is $100 shipped and 30 pounds.
a 12v 50ah Lithium Iron battery is $450 and 15 pounds.

While I would love a Lithium battery, I cant see spending an additional $350 to save 15 pounds??

I need words of wisdom,

Slack

Max amp draw from your motor is about 30 amp.

50 ah / 30 amp = 1.67 hr or 100 min.

[Slackdaddy]

Thanks,
From what I am reading, you very little speed going over mid range on the trolling motor.
Mid range on my motor is 14.5 amps (round to 15)

my max trip would be 1.9 miles each way, so 4 miles round trip. Remember I am only using this to get to fishing spots, not trolling etc.

Looking at a 35ah SLA battery (22#) for $68.00,, That would net me about 2.3 hours of run time.
at 3 mph on mid speed, that should net me ~ 6.9 miles travel per charge.

Max amp draw from your motor is about 30 amp.

50 ah / 30 amp = 1.67 hr or 100 min.

[FishnFun]

Yep, good to go at 35 ah.

[Oldbayrunner]

Thanks,
From what I am reading, you very little speed going over mid range on the trolling motor.
Mid range on my motor is 14.5 amps (round to 15)

my max trip would be 1.9 miles each way, so 4 miles round trip. Remember I am only using this to get to fishing spots, not trolling etc.

Looking at a 35ah SLA battery (22#) for $68.00,, That would net me about 2.3 hours of run time.
at 3 mph on mid speed, that should net me ~ 6.9 miles travel per charge.

That math isn't quite correct.... Your 36# should amp draw full power somewhere between 17-21 amps the correct math to calculate run time is; Battery ah, divided by amp draw, times battery drop off factor. So for an Sla battery given your amp draw would look like this: 35 ah ÷ 15 amps X .85 drop off = 1.98 hrs run time....

Using the standard 5/3 TM controller wastes a lot of energy in low to mid high speed settings, that's where using a variable speed motor or adding a PWM controller can add to runtime as much as 5X. A 35# at speed 1 with a 5/3 controller burns roughly 5-6 amps vs less then 1 amp draw using a variable speed motor or a pwm. As you increase speed the margin drops to roughly 3X more run time around the mid to mid high range. Past that the controller type doesn't matter. So given the same scenerio your draw would decrease to using roughly 8-9 amps and gain in run time At mid range; 35 ÷ 9 X .85 = 3.30 hrs run time

A lifepo4 lithium battery gains roughly 30% more run time due to remaining at a constant voltage through the vast majority of the charge so a 35ah lithium with the 5/3 would look like this; 35 ÷ 15 X .97 = 2.26 hrs run time. Couple that with a Variable or pwm 35 ÷ 9 x .97 = 3.77 hrs run time. Also where your gain is less weight. 25 lbs for sla vs roughly 10lbs and charge life goes into the thousands vs hundreds.

Food for thought, another misunderstood factor. Though a larger trolling motor will use more amps if running at high speed. One gains efficiency and uses less amps to achieve the same speed as a smaller thrust motor. Example; Your 36# weighs around 20 pounds, a 35ah sla battery weighs in usually in at 25 pounds so coupled a total of 45lbs in added kayak weight. Now drawing 15 amps, depending on currents and wind, might net you 3-3.5 mph on a very calm day. My 65# variable brushless TM weighs in at 13.4 pounds & My 100ah lipo4 battery weighs 28 lbs, so I'm in at a combined 41.4 lbs so slightly less weight. At an 8-9 amp draw in the same conditions it does 3-3.5 mph using only around 30% of it's power. I can troll at between 2-2.5 mph using only a 5-6 amp draw.

I have been using different power combos now for over 6 years, I changed to lipo4 lithium a few years ago. Both battery types will work, for me though I prefer using the most power & getting the best runtime while using the least amount of amp draw I can & at the least amount of weight. I've ran into times over the years where what I was using wasn't enough handle conditions that came up on the bay and it isn't fun. So hopefully my post adds a little more insight to planning your power.

[Slackdaddy]

Thanks for the write up.
I knew the resistor controller in the Minn Kota is very inefficient, and as I get more into it plan to change out to a PWM controller.

I have less then $100 is the motor and battery, this should get me to my farthest fishing spot and back.
Even if I were to fall slightly short, I could easily "assist paddle" .
I'll use what I have to fish these areas this summer, and determine if they are worth fishing, how often I go, how far I go, etc.

At the end of the summer I will evaluate my needs once I have the experience under my belt.
At that point I will determine the battery and motor I need to take full advantage of this area.

That math isn't quite correct.... Your 36# should amp draw full power somewhere between 17-21 amps the correct math to calculate run time is; Battery ah, divided by amp draw, times battery drop off factor. So for an Sla battery given your amp draw would look like this: 35 ah ÷ 15 amps X .85 drop off = 1.98 hrs run time....

Using the standard 5/3 TM controller wastes a lot of energy in low to mid high speed settings, that's where using a variable speed motor or adding a PWM controller can add to runtime as much as 5X. A 35# at speed 1 with a 5/3 controller burns roughly 5-6 amps vs less then 1 amp draw using a variable speed motor or a pwm. As you increase speed the margin drops to roughly 3X more run time around the mid to mid high range. Past that the controller type doesn't matter. So given the same scenerio your draw would decrease to using roughly 8-9 amps and gain in run time At mid range; 35 ÷ 9 X .85 = 3.30 hrs run time

A lifepo4 lithium battery gains roughly 30% more run time due to remaining at a constant voltage through the vast majority of the charge so a 35ah lithium with the 5/3 would look like this; 35 ÷ 15 X .97 = 2.26 hrs run time. Couple that with a Variable or pwm 35 ÷ 9 x .97 = 3.77 hrs run time. Also where your gain is less weight. 25 lbs for sla vs roughly 10lbs and charge life goes into the thousands vs hundreds.

Food for thought, another misunderstood factor. Though a larger trolling motor will use more amps if running at high speed. One gains efficiency and uses less amps to achieve the same speed as a smaller thrust motor. Example; Your 36# weighs around 20 pounds, a 35ah sla battery weighs in usually in at 25 pounds so coupled a total of 45lbs in added kayak weight. Now drawing 15 amps, depending on currents and wind, might net you 3-3.5 mph on a very calm day. My 65# variable brushless TM weighs in at 13.4 pounds & My 100ah lipo4 battery weighs 28 lbs, so I'm in at a combined 41.4 lbs so slightly less weight. At an 8-9 amp draw in the same conditions it does 3-3.5 mph using only around 30% of it's power. I can troll at between 2-2.5 mph using only a 5-6 amp draw.

I have been using different power combos now for over 6 years, I changed to lipo4 lithium a few years ago. Both battery types will work, for me though I prefer using the most power & getting the best runtime while using the least amount of amp draw I can & at the least amount of weight. I've ran into times over the years where what I was using wasn't enough handle conditions that came up on the bay and it isn't fun. So hopefully my post adds a little more insight to planning your power.

[FishnFun]

That basic math is correct. A simple direct calculation can be used for guidance. Of course it's for an ideal system with no losses or inefficiencies.

You have added inefficiency factors for real systems. If you add all the estimated losses, of course you'll get a "better answer." But estimations are just that, estimations with uncertainty. Accounting for all the details (temperature, battery variation, controller losses, load, etc.) is nice analysis, but the practical matter is to use basic math as guidance as well as use a higher capacity battery to ensure the system will get the job done. Sort of a "safety factor." Some may refer to it as a "bit overkill." The 35 ah seems like a reasonable battery. Actual usage will give you a better "feel" of your system.

[Slackdaddy]

A couple questions.
Adding a PWM controller, in place of the 5/3 resistor controller, on a basic brushed motor: will the PMW add much efficiency to the brushed motor? or do I need a VS motor or Brushless motor to see gains with a PWM controller?

What type of gains will I see using PWM with a basic brushed Trolling motor?

Trolling motor manufactures give zero info on the type of motors or controllers used,, On the low end, what is a decent brushless or VS motor?

Thanks,
Slack

That math isn't quite correct.... Your 36# should amp draw full power somewhere between 17-21 amps the correct math to calculate run time is; Battery ah, divided by amp draw, times battery drop off factor. So for an Sla battery given your amp draw would look like this: 35 ah ÷ 15 amps X .85 drop off = 1.98 hrs run time....

Using the standard 5/3 TM controller wastes a lot of energy in low to mid high speed settings, that's where using a variable speed motor or adding a PWM controller can add to runtime as much as 5X. A 35# at speed 1 with a 5/3 controller burns roughly 5-6 amps vs less then 1 amp draw using a variable speed motor or a pwm. As you increase speed the margin drops to roughly 3X more run time around the mid to mid high range. Past that the controller type doesn't matter. So given the same scenerio your draw would decrease to using roughly 8-9 amps and gain in run time At mid range; 35 ÷ 9 X .85 = 3.30 hrs run time

A lifepo4 lithium battery gains roughly 30% more run time due to remaining at a constant voltage through the vast majority of the charge so a 35ah lithium with the 5/3 would look like this; 35 ÷ 15 X .97 = 2.26 hrs run time. Couple that with a Variable or pwm 35 ÷ 9 x .97 = 3.77 hrs run time. Also where your gain is less weight. 25 lbs for sla vs roughly 10lbs and charge life goes into the thousands vs hundreds.

Food for thought, another misunderstood factor. Though a larger trolling motor will use more amps if running at high speed. One gains efficiency and uses less amps to achieve the same speed as a smaller thrust motor. Example; Your 36# weighs around 20 pounds, a 35ah sla battery weighs in usually in at 25 pounds so coupled a total of 45lbs in added kayak weight. Now drawing 15 amps, depending on currents and wind, might net you 3-3.5 mph on a very calm day. My 65# variable brushless TM weighs in at 13.4 pounds & My 100ah lipo4 battery weighs 28 lbs, so I'm in at a combined 41.4 lbs so slightly less weight. At an 8-9 amp draw in the same conditions it does 3-3.5 mph using only around 30% of it's power. I can troll at between 2-2.5 mph using only a 5-6 amp draw.

I have been using different power combos now for over 6 years, I changed to lipo4 lithium a few years ago. Both battery types will work, for me though I prefer using the most power & getting the best runtime while using the least amount of amp draw I can & at the least amount of weight. I've ran into times over the years where what I was using wasn't enough handle conditions that came up on the bay and it isn't fun. So hopefully my post adds a little more insight to planning your power.

[ronaultmtd]

For those considering purchasing a Lithium battery and look at the Company warrantee As proof of quality...my Dakota Lithium 12v 10aHr LiFEPO4 battery has an 11 year warrantee...it failed back in March at 256 hours of use and I sent it back, proof of purchase, etc., etc. the company agreed to make it right on June 16th...approved a replacement...on July 3rd I inquired if they still were going to send me a replacement battery...on July 13th they replied it should be shipped within a week or so...If I get a replacement I will update...

[Oldbayrunner]

Adding a PWM controller, in place of the 5/3 resistor controller, on a basic brushed motor: will the PMW add much efficiency to the brushed motor?

A 5/3 controller is very inefficient and a lot of energy is wasted, what a PWM (pulse width modulator) does is send pulses to the motor so the motor runs on only the electricity it needs at a given percentage setting thereby saving battery by using less amp draw from the motor. This run time savings works in the low to mid-high amp draw range. As one runs the motor at a higher setting then the amp draw starts equalizing out saving less to nothing.

do I need a VS motor or Brushless motor to see gains with a PWM controller?


No a pwm 2works with a brushed motor.... A variable motor is still a brushed motor and has a built in pwm in the control head..... A brushless motor is totally different. Simplicity explanation is brushless motor has no brushes therefore there is less wear and friction without anything rubbing against the armature. That equates to a longer lasting motor due to less wear and with less friction it uses less battery draw to operate. It operates completely different than a brushed motor and current is created using a Hall effect sensor. it too is a variable speed but unlike a variable pwm control it is a stepless hall effect controller. All in all it uses roughly 20-30% less amp draw then a brushed motor using a pwm.

A variable speed cost will depend on size motor anywhere from around $149.00 for a 36# up to roughly around $350.00 for a 55#.

A brushless can run any where from $349.00 for a 65# up depending on size.

Contrary to a popular belief will a larger trolling motor use more battery. In answer, Yes if one is running at higher speeds but a larger motor generally uses less battery at lower to mid high speeds then a smaller trolling motor due to it's higher rpm and greater thrust. To achieve the same speed a smaller motor needs to run at a higher setting. example a 35# motor will use 17-21 amps per hour at 100% full power to roughly go around 3-3.9mph on a heavier loaded fishing kayak. That same kayak using a 55# will use about the same amp draw but be using roughly 50-60% of it power. My 65# brushless I can cruise @ 3-3.5mph and be drawing only between 8-9amps per hr. For me to troll at between 2-2.5 mph I usually draw 5-6 amps per hr. less amp draw equals longer run time.

[Slackdaddy]

Thanks for the more details.
I am expecting to see 15 amp draw and ~2 MPH with my brushed Minn Kota 36# on mid setting (factory resistor controller)
After my trial runs the next month or so, I will probably jump right into a Protruar 1.0,,, you are seeing a 5-6 amp draw at ~2mph ?? That is a heck of an efficency jump from 15 amps.

Are you Happy with the protruar ??

Thanks,
Slack

Adding a PWM controller, in place of the 5/3 resistor controller, on a basic brushed motor: will the PMW add much efficiency to the brushed motor?

A 5/3 controller is very inefficient and a lot of energy is wasted, what a PWM (pulse width modulator) does is send pulses to the motor so the motor runs on only the electricity it needs at a given percentage setting thereby saving battery by using less amp draw from the motor. This run time savings works in the low to mid-high amp draw range. As one runs the motor at a higher setting then the amp draw starts equalizing out saving less to nothing.

do I need a VS motor or Brushless motor to see gains with a PWM controller?


No a pwm 2works with a brushed motor.... A variable motor is still a brushed motor and has a built in pwm in the control head..... A brushless motor is totally different. Simplicity explanation is brushless motor has no brushes therefore there is less wear and friction without anything rubbing against the armature. That equates to a longer lasting motor due to less wear and with less friction it uses less battery draw to operate. It operates completely different than a brushed motor and current is created using a Hall effect sensor. it too is a variable speed but unlike a variable pwm control it is a stepless hall effect controller. All in all it uses roughly 20-30% less amp draw then a brushed motor using a pwm.

A variable speed cost will depend on size motor anywhere from around $149.00 for a 36# up to roughly around $350.00 for a 55#.

A brushless can run any where from $349.00 for a 65# up depending on size.

Contrary to a popular belief will a larger trolling motor use more battery. In answer, Yes if one is running at higher speeds but a larger motor generally uses less battery at lower to mid high speeds then a smaller trolling motor due to it's higher rpm and greater thrust. To achieve the same speed a smaller motor needs to run at a higher setting. example a 35# motor will use 17-21 amps per hour at 100% full power to roughly go around 3-3.9mph on a heavier loaded fishing kayak. That same kayak using a 55# will use about the same amp draw but be using roughly 50-60% of it power. My 65# brushless I can cruise @ 3-3.5mph and be drawing only between 8-9amps per hr. For me to troll at between 2-2.5 mph I usually draw 5-6 amps per hr. less amp draw equals longer run time.

[Oldbayrunner]

Are you Happy with the protruar ??

Thanks,
Slack

So far it is proving to be the best most efficient motor I have used over the last 6 years. I dont believe they are making this particular one any longer and went to a 12v 3hp (too heavy and uses too much battery IMO). However there is another excellent one being the Seamax Powermax 12v 65# brushless.

I also see 3-3.5 mph using between 8-9amps.... That is under normal light wind and tide days otherwise it jumps to around 15-18 amps on normal windy days.

[Slackdaddy]

If you google "Brushless trolling motor"
Some of the returns are exact copies of the Protraur 1.0 65# unit,
Most have the specs word for word,, there is one claiming 3hp lol

and Amazon has one sold under AQUOS
https://www.amazon.com/AQUOS-35-5inc...ag=googhydr-20

So far it is proving to be the best most efficient motor I have used over the last 6 years. I dont believe they are making this particular one any longer and went to a 12v 3hp (too heavy and uses too much battery IMO). However there is another excellent one being the Seamax Powermax 12v 65# brushless.

I also see 3-3.5 mph using between 8-9amps.... That is under normal light wind and tide days otherwise it jumps to around 15-18 amps on normal windy days.