Trolling Motor -> e Bike - Great Idea, I love it !
I have a 34Lb
Watersnake trolling motor, a Pulse Width Modulator (PWM) & a 50Amphr Lithium Ion battery. - PWM is probably similar to Battery Saver Circuitry. I intend to be able to move the motor & battery on both my boat & bicycle.
A few thoughts: -
1. Cooling: the motor may need cooling - To add air cooling fins is easy - a slip-over with cooling fins attached, AL or steel cylinder with thermal conducting paste inside. Remove when boating. I notice this has been discussed earlier.
2. Add a throttle: The cheap but excellent Watersnake does not have a Variable
Pulse Width Modulator (PWM) so I paid $20AU for one & got the local JayCar gadget shop to add a 900mm (~30 inch) electrical cable extension to control the motor from the cockpit of my sailboat - a Hobie Tandem Island. The PWM with throttle extension would allow a much better battery range at non max speeds & on a bike, a handlebar control.
3. Battery life & weight:
Li Ion battery recharge cycle of 500 to 1000 times - Lead/acid deep cycle ?
so I can't see the Li Ion cell being worn out on my Tandem Island and bicycle
Li Ion battery weighs 7kg (~15lbs). - Lead/acid deep cycle (~20kg /44lbs)
Li Ion battery size 200x450x40mm (~8x18x2") - Lead/acid 350x250x200mm(12x10x8")
It is easy to move & house on a bicycle & doesn't increase bicycle weight by much
Please correct me if I'm wrong but, compared to deep cycle Lead/Acid heavy batteries, the Li Ion doesn't mind discharging to ~10% which makes it really a 50 minus 10 Amp hour battery - Lead/Acid batteries really, really dislike discharges less than about 50 or 60%. so a 50Ahr Li Io is fairly similar to a 80 hr Lead/Acid battery (~20kg /44lbs).
4. Watersnake motors are about 1/3 the price of
Minn Kotas because they do not have an inbuilt VPM. - about $200AUD + $20AUD for a PWM)
5. PWM: You can easily run the PWM on any trolling motor - you leave the motor on full forward & connect the PWM between the battery & the motor. This gives you a throttle to have on your handlebar (& of course you keep the reverse for, as mentioned, giggles)
6. So if you have a Lithium Ion battery, using it on your bike would not wear it out. It is quite small (200mm x 450mm x 40mm /~8" x 18" x 2") & much lighter.
7. Pandemic Lockdown Project, - I have a 180W flexible lightweight detachable solar panel & a battery charger on the stern of my Hobie Tandem Island for almost continuous motor-sailing - I'm thinking of adding panel attachment to my bike trailer for almost continuous ecycle-motoring
- now that's a good Coronavirus lockdown project !
As for speed - under motor, the Hobie Tandem Island non planing but wave piecing hull in calm conditions easily hits 10kmh to 15kmh (~12mph) It starts to "sort-of plain" under sail at these speeds & up to about 25kmh before you start breaking things.
- Perhaps during the Coronavirus Lockdown, which here in the state of Victoria Australia, looks like to be August or September, I might just sneak out at dusk & maybe learn to ride the e bike in reverse? While observing
social distancing & of course while
essential food gathering - just kidding!
Pic of PWM with the entended cables for throttle & switch (forward, backward & stop) Battery in & motor out attach on the top side of the pic. All cabling & electrical junctions sit in waterproof casing (100mm = 4inches I think)