Colorado XT trolling motor mod

Have an XT and have been using it for 3 months each summer in the E Sierras. It has a 30 lb min kota trolling motor which I love using. The problem is the battery. It is very heavy and am getting to use it less and less. I purchased a 35 amp hr battery that is way lighter and is easy to tote around. I also am building a pulse wave modulator (PWM ) to longer use, and variable speed control. Does anyone use one of these and is there a heating problem with the heat sinks. I need to know if I need to add a cooling fan. With the lighter battery I plan on using the trolling motor on every outing. Thanks.

bobschultz wrote:Have an XT and have been using it for 3 months each summer in the E Sierras. It has a 30 lb min kota trolling motor which I love using. The problem is the battery. It is very heavy and am getting to use it less and less. I purchased a 35 amp hr battery that is way lighter and is easy to tote around. I also am building a pulse wave modulator (PWM ) to longer use, and variable speed control. Does anyone use one of these and is there a heating problem with the heat sinks. I need to know if I need to add a cooling fan. With the lighter battery I plan on using the trolling motor on every outing. Thanks.

I wish I had knowledge of this for you sorry I don't. I am sure someone will chime in or maybe we can get [You must be registered and logged in to see this link.] to comment he recently built his own battery.

bobschultz wrote:Have an XT and have been using it for 3 months each summer in the E Sierras. It has a 30 lb min kota trolling motor which I love using. The problem is the battery. It is very heavy and am getting to use it less and less. I purchased a 35 amp hr battery that is way lighter and is easy to tote around. I also am building a pulse wave modulator (PWM ) to longer use, and variable speed control. Does anyone use one of these and is there a heating problem with the heat sinks. I need to know if I need to add a cooling fan. With the lighter battery I plan on using the trolling motor on every outing. Thanks.

My guess is that the PWM manufacturer will give you the specifications as to its capability, and if they do not specify a heat sink, my guess is that it should not need one?  I don't know but the point of PWM is that energy is NOT dissipated as heat.  

On a different note, I just don't get why manufacturers still not use PWM as a standard part of the design.  The runtime at low levels with PWM is night and day difference from using a resistor.

Have you measured your max speed with the 30 lbs thrust motor?

Yes, with my garmin striker. Never use top speed but with 4 th gps says 2.3 mph. I understand that the TM uses approx 30 amps at all speeds .

Had PWM housed in a  waterproof case and wired it to hand held box up by the colorado seat.  No problems overheating.  I did trip the 50am circuit breaker when running back in high winds so make sure you can take the PWN out of the loop and hook trolling motor directly to battery if there are issues on the water.  I used powerpole connectors.

jmytuna wrote:Had PWM housed in a  waterproof case and wired it to hand held box up by the colorado seat.  No problems overheating.  I did trip the 50am circuit breaker when running back in high winds so make sure you can take the PWN out of the loop and hook trolling motor directly to battery if there are issues on the water.  I used powerpole connectors.

Now that was great info thanks so much for sharing. I am sure this will help many guys out with there builds.

So the PWM will help you get more time out of your battery?

My old Minn Kota Endura used the same amount of battery power at lower speeds vs speed 5. Going slower just generated more heat through resistors/speed coils so my 50# optima didn't even make it through the day no matter how much I babied it. PWM can dial in speed, infinite adjustments without surges, way more efficient.
Eventually moved to brushless Haswing and Lithium battery when I sold the Colorado

Thank you.