Have anyone tried using 4S Lipo on a 12V trolling motor?

luvxu

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Jun 4, 2012
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Hi All,
I have been searching everywhere but can't seem to see any post on using 4S Lipo (16.8V) on a 12V trolling motor.

In my current setup, there are 6 Turnigy batteries (hardcase 5000mA) connected to give 48V 10AH with a DC-DC converter to convert 48V down to 12V for running a motorguide trolling motor. This setup works fine but I would love to get rid of the heavy DC-DC converter if I can connect all the batteries in parallel and run the trolling motor directly on 16.8V output.

I wonder if the trolling motor's controller can tolerate 16.8V? Have anyone successfully tried this setup?

Thanks,
 
Not Lipo but I plan using setup of NCA 18650 cells at 43V and 44Ah. Only 10kg incl BMS and housing.
I use a adjustable stepdown convertor 12-15V 48A output for the trolling motor.
Comparable power to a 12V 220Ah Lead Acid considering the bad Peukert effect of lead based batteries.
 
OP, I don't know trolling motors but I've been experimenting with automotive 12VDC devices/accessories on 4S RC Lipo and I've yet to run across a device that didn't work fine on 16.8V. As long as there's no voltage sensitive control circuitry and mindful not to push a much peppier motor too hard/fast, I think it would be okay?
 
I was watching this video https://www.youtube.com/watch?v=QKyVKb7sGLA . That showed a small 30lb motor that is similar to mine and it showed that there is no electronic controller board in the motor head. This means that the speed of the motor is probably controlled by resistor coils instead of electronic circuit which is much less susceptible to change in the input voltage. So Ykick may be right, it could actually work with the 4S 16.8V lipo. I'll give it a try and report back here if it will work or not.
 
I too have a trolling motor running on a acid brick, and ide love to switch over to lipo.
i have about 12x 4s hardcase packs, all with 1 bad cell. i was going to use the 36 good cells in a 3s setup for 12.6v 60ah. But if i can run 4s with the 36 cells, thats 16.8v 45ah. I would imagine the speed gains of 16.8 vs 12.6 would be a couple mph atleast. but i wonder if it would hurt the motor?
Please let me know how you turn out, as ide love to put these spare cells to use. i just dont want to burn up my motor!
 
I'm running my trolling motor fine so far on a 48 to 12V DC DC convertor for golf carts (rated output 12V 30 amps) that I got off Amazon, on my 48V Headway pack. It puts out 12.6V and I haven't had any issues with my Minnekota 40 Endura with maximizer. That might be an option for you, although evidently you could get as many amps as you want from a 4S Lipo solution, if the higher voltage does'nt burn out the motor from the higher amp suck that that voltage would entail. Higher voltages (and not that much higher) can burn out the motor easily, as the amps pulled is non-linear with voltage but rises in a <cubic?> function of prop rpm, from what Jeremy Harris has indicated - the ES expert on trolling motor power requirements - check him out.
 
It works.

Last week I did a dry test with the motor connected to the 4S battery in my garage. I let it run for 2 min and then shut it off as I think the motor may need to run in the water to get the cooling benefit.

Then finally yesterday the weather had warmed up and melted all the snow that we have here in Massachussetts. I took the boat out with my two young avid sailors and cruise the lake for over an hour. I brought along with me a backup 48V 10A with 48-12V DC converter just in case my 4S run out of juice. But I didn't need to use the back up battery at all.

My boat is a fairly heavy fiberglass 14' sail boat (probably 400-500 lbs, it is an antique Flying Tern that no one seem to have anymore) that run with a motorguide 30lb engine. So the speed is not super fast but it got me cruising around the lake (this is a large lake, around 100 acres) with my kids with good enough speed. If you run this motor on a lighter canoe then I can imagine that you would get a very fast speed.

The motor has 5 gears forward and 2 gears reverse. In the first 20 min I was running only 3rd gear just to test out the motor. It worked so I began to venture up to the 4th and 5th gears. Both of them worked well for over 15 min at a time. I continually touch the motor head to see if it heated up or not but it didn't. As for the motor it worked well to the end with no sign of a melt down.

Over all, I think this setup still need to be tested for longer durations (e.g., several hours at a time). But, the initial result is encouraging. If this works well then we have a very inexpensive and light setup for use on small boats and canoes. And since it is electric, there is no noise pollution on the lake which is quite wonderful. If anyone out there who got any result on similar setup please share it with us.
 

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Great to hear the update! Always interested in this RC Lipo 4S - 12VDC topic and your bravery is to be commended. Also looks like a wonderful time on the water!
 
It will work just fine. The only real limitation of a trolling motor are the brush armature and bearings.
Remember that the resistance of the motor doesnt change so higher voltage results in higher amp draw.
This can cause bad efficiency or even worse thermal buildup which can result in broken motor because it was not designed for higher power.
 
I run my 12V trolling motor at 24V, so 4s Lipo shouldn't be an issue. Mine pushes a lighter load that a heavy boat. Plus I use a brushed motor PWM controller for better efficiency and better control current, and have all the speed wires of the motor connected in parallel for lowest resistance for less waste heat inside the motor shell.
 
Very interesting John, can you post the type of trolling motor and the brushed pwm controller that you have used. If it is possible, can you show some pictures and a diagram of how to modified the trolling motor to work with the brushed pwm controller?
 
Was thinking about this recently. 12v motor should run fine on 4S. If you use a PWM controller as is widely recommended you can just chuck a voltmeter on the PWM to Motor wiring and check at what setting the motor is getting exactly 12v.

I have been pondering how to run a 12v motor from 6S or higher battery packs, considering that 25v would probably burn out the 12v brushed motor pretty quick. The light went on when my tiny little brain finally figured out that any voltage battery could be used with a suitably rated PWM controller. Just test at what setting the desired maximum voltage is attained and limit the adjustment range to below that setting. If you were clever you could add a resistor to the Pot input to limit the output and obtain the desired range. If you were really clever you could use a trimpot on the input and make your PWM controller a variable input voltage unit.

Another option that adds some safety factor to the package (while possibly being annoying in action) is to add a circuit breaker that is rated at max motor power. It has been explained elsewhere that as voltage and motor speed rise amp draw rises exponentially. If the motor usually pulls 30 amps at 12v while accelerating, you could run a higher voltage battery through a PWM with a 30 amp circuit breaker. If you go much above 12v to the motor, it will spin faster leading to higher amp draw triggering the circuit breaker. The safe working range on this one probably needs to be found by either trial and error or a smarter person than me.
 
From the international boat standard ISO 10133:
4.5 All d.c. equipment shall function over a voltage range at the battery terminals as follows:
- for a 12 volt system: 10.5 V to 15.5 V;
- for a 24 volt system: 21 V to 31 V.

4 * 3.7 V = 14.8 V So, why worry?
 
catharsis said:
From the international boat standard ISO 10133:
4.5 All d.c. equipment shall function over a voltage range at the battery terminals as follows:
- for a 12 volt system: 10.5 V to 15.5 V;
- for a 24 volt system: 21 V to 31 V.

4 * 3.7 V = 14.8 V So, why worry?

3.7V/cell is nominal. Top charge is 4.2V/cell * 4S = 16.8V
 
Charging and driving at the same time? If solar boat, yes...
 
Hi,

So I have been told multiple times that a PWM controller would give the trolling motor better efficiency but no one ever gave me the specifics on how to hook everything up for it to work. After reading a number of posts, I think this may be the answer, please correct me if I am wrong here before I blew up everything. :)

Part list:
1. motorguide 12v, 30#, http://www.amazon.com/MotorGuide-12-Volt-Freshwater-Trolling-30-Pound/dp/B004HO9W36/ref=sr_1_1?ie=UTF8&qid=1447170529&sr=8-1&keywords=motorguide+r3-30
2. PWM controller 9-60V, 40A, http://www.amazon.com/DROK-Controller-Regulator-Adjustment-Potentiometer/dp/B00J20OL7C/ref=sr_1_2?ie=UTF8&qid=1447170591&sr=8-2&keywords=pwm+controller+40a
3. Lipo battery 4S: http://www.ebay.com/itm/4-pkTurnigy-4S-5000mAh-Lipo-Battery-14-8v-20-30C-Hard-Cased-Brand-New-USA-Seller-/281358947053?hash=item41824cd2ed:g:mgoAAOSwq5lTmGjp

Connection:
1. turn down PWM pot, connect PWM inputs to Lipo battery connectors
2. turn motor handle to neutral, connect motor battery leads to output of PWM controller
3. turn motor handle to 5 max
4. turn on PWM pot, the motor should start running

Will this configuration work, do you know? If it works then may be 6S battery can be used to give it some extra juice. Is there some easy way to make sure that the motor won't get burn using the higher voltage battery?

May be this is not the optimal way for doing thing but if I don't have to open up the motor to replace the controller coil there then it would be the easiest.
 
luvxu said:
Hi,

So I have been told multiple times that a PWM controller would give the trolling motor better efficiency but no one ever gave me the specifics on how to hook everything up for it to work. After reading a number of posts, I think this may be the answer, please correct me if I am wrong here before I blew up everything. :)

Part list:
1. motorguide 12v, 30#, http://www.amazon.com/MotorGuide-12-Volt-Freshwater-Trolling-30-Pound/dp/B004HO9W36/ref=sr_1_1?ie=UTF8&qid=1447170529&sr=8-1&keywords=motorguide+r3-30
2. PWM controller 9-60V, 40A, http://www.amazon.com/DROK-Controller-Regulator-Adjustment-Potentiometer/dp/B00J20OL7C/ref=sr_1_2?ie=UTF8&qid=1447170591&sr=8-2&keywords=pwm+controller+40a
3. Lipo battery 4S: http://www.ebay.com/itm/4-pkTurnigy-4S-5000mAh-Lipo-Battery-14-8v-20-30C-Hard-Cased-Brand-New-USA-Seller-/281358947053?hash=item41824cd2ed:g:mgoAAOSwq5lTmGjp

Connection:
1. turn down PWM pot, connect PWM inputs to Lipo battery connectors
2. turn motor handle to neutral, connect motor battery leads to output of PWM controller
3. turn motor handle to 5 max
4. turn on PWM pot, the motor should start running

Will this configuration work, do you know? If it works then may be 6S battery can be used to give it some extra juice. Is there some easy way to make sure that the motor won't get burn using the higher voltage battery?

May be this is not the optimal way for doing thing but if I don't have to open up the motor to replace the controller coil there then it would be the easiest.

Speed 5/max setting on the trolling motor speedswitch is a direct connection to the brushed DC motor in the pod.
All other speedsettings will put a large resistor in series which are mounted on the side of the pod. The voltage drop across these resistors will result in lower voltage on DC motor terminals, thus lowering speed. Needless to say a very in-efficient way of speedreducing because current will burn up in the resistors.

The PWM controller chops up the voltage into squarewaves for a certain period (pulse width) which is the duty cycle. When doing this on a high frequency (kHz) the DC motor will see an average voltage as result. You can regulate these pulse-widths with the controller to set a point between 0 & 100% of the DC battery voltage. Resulting in variabel speed control with very high efficiency.

I have removed the speedswitch in whole and put the PWM controller inside my own trollingmotor housing.
Then mounted a 5 v regulated speed control for electric scooters/mopeds to regulate the speed.
 
Hi Monstarr,

Thank you for the explanation, it really help. Would you mind share the part numbers for your motor, pwm and battery. Some pictures or diagrams would be helpful. If the system has been working reliable for you then I just want to copy it so that I don't have to deal with any unpleasant surprise of building it from scratch.

Thanks
 
catharsis said:
Charging and driving at the same time? If solar boat, yes...
the 4.2v is not "charging"... lipo batteries are 4.2v per cell when fully charged, and discharge to about 3.2... making the average between them 3.7 ((3.2+4.2)/2=3.7)
That said, I only charge my multicell lipos to 4.15 to leave some headspace, and I never discharge them lower than 3.6v. This extends their life considerably.
 
luvxu said:
Hi Monstarr,

Thank you for the explanation, it really help. Would you mind share the part numbers for your motor, pwm and battery. Some pictures or diagrams would be helpful. If the system has been working reliable for you then I just want to copy it so that I don't have to deal with any unpleasant surprise of building it from scratch.

Thanks

I use a 24 V 80'-ish' lb Motorguide trolling motor with a Kelly 24 V brushed controller.
http://kellycontroller.com/kds36100e100a24v-36v-mini-brushed-controller-p-270.html
Any PWM brushed controller built for the operating voltage range will do. Just check the nominal current handling. There is nothing wrong with a little additional current handling because when trolling you will ask max current all the time because of the waterdrag. But this is common sense.

Set up is easy. Just hook on the battery to the input (& the key ignition). Connect the throttle input wires (5v supply, 0-5 v & GND) to the gas handle or a regular pot meter. Then installed the black & red (direct lead) motor wires to the controller output.

I mounted the Kelly controller on an aluminium plate and then bolted the plate to the original mounting holes of the speedswitch within the housing. Furthermore I installed a small fan and air-in- & outlets to get the airflow needed for cooling.

For easy throttle control I clamped a flexible vertical joint around halfway to the shaft and insert a arm-extension on this joint. On the end of this extension I mounted the gashandle. This way I get a similar way of control as a standard ICE outboard would have.

As battery I use a 8S (24V) LiFePO4 70 Ah battery. But this could also be a regular series lead setup.

Adding PWM control this way can be done very cheaply. You only see this type of speedcontrol with more expensive type trolling motors. Although the overall design could have been better, especially the flexibele connection on the motorshaft is not very rigid and has room for improvement, but I have used it a few times and I am happy with the result. :D

:!: Only thing I don't have anymore is reverse motion. The Kelly controller doesnt have this function. You can use a switch to flip the motor leads but normally those are not build for higher amps or are very costly. I didnt look into this a lot because I dont miss it that much. Perhaps someone here has a good solution for this problem ?
 
Montstarr, It is too bad that you don't have reverse. I use this feature all the time on my boat for backing up. I guess that if you have not removed the motor controller handle then you can use it to get into reverse, right? I like your system as it uses 24V trolling motor with much more thrust than mine (80# versus 30#). I have a few 48V lipo batteries for my ebike. I wonder if I can reuse the ebike batteries for the boat by implementing a trimpot to limit the output voltage as suggested by KalSteve? I have looked into 48V trolling motors but they are outrageously expensive comparatively.
 
luvxu said:
Montstarr, It is too bad that you don't have reverse. I use this feature all the time on my boat for backing up. I guess that if you have not removed the motor controller handle then you can use it to get into reverse, right? I like your system as it uses 24V trolling motor with much more thrust than mine (80# versus 30#). I have a few 48V lipo batteries for my ebike. I wonder if I can reuse the ebike batteries for the boat by implementing a trimpot to limit the output voltage as suggested by KalSteve? I have looked into 48V trolling motors but they are outrageously expensive comparatively.

No this Kelly controller just doesnt have a reverse function. Kelly does sell them though to add the reverse option.
http://kellycontroller.com/reversing-contactor-zjwt-24vdc-coils-150amps-p-580.html
Connection schematics
http://kellycontroller.com/diagram-of-reversing-contactor-for-kelly-controller-p-700.html

I think dividing voltage with a resistor is super in-efficient and impossible to be honoust due to the very large currents.
You can use a 48 VDC - 24VDC converter but finding them with high current capability will be a costly challenge I think.
Split the pack in two and put them in parallel to make it a 24 VDC pack? You will only have to buy a new BMS.

Tip on getting a 24 VDC for cheap, try to search online for faulty 24 V trolling motors. Usually you will see the speedcontacter broken or the brush armature melted or with worn out brushes. Easy and cheap fix. Only in the case if water has ingressed into the motorpod I would skip it. If there is corrosion inside the motorpod I would not want it anymore.

Or search ali express / alibaba / ebay for a 24 v motorpod only on which you can mount the 24 VDC PWM control.
For example, http://www.aliexpress.com/item/DHL-...utboard-motor-parts-for-sale/32423232085.html
 
That's a lot of good information Monstarr. I will look into it for a used 24V motor. If I keep the motor handle but use it only max forward or max reverse then there should be no resistor in the motor, right? If there is no resistor then there should be no wasted power, right? In this way I can use the PWM for controlling speed and the motor handle for forward, reverse and steering.
 
While looking around for a 24v motor, I found this motor on ebay for $499.95 which looked to be employing some kind of PWM controller (http://www.ebay.com/itm/24V-2-hp-110-lbs-Variable-Speed-Transom-Mount-Motor-Electric-Trolling-Motor-/221804815552?hash=item33a498e4c0:g:HngAAOSwHnFVg7D1&vxp=mtr).

It looks like people like it a lot (https://www.youtube.com/watch?v=5i8FzBrDAxA).

At this price it doesn't look like I should build my own any more...
 
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