Have you lowered cutoff speed to 10mph to get over 100mi battery range?

Mike leroy

Active Member
The Bike as Transportation blog is very good! He lowered his cut off to 10mph in 2011 and got 120 miles.

Does anyone have more recent results to share?

Even the same battery chemistry from the same manufacturer can be configured for different results. I am trying to understand the significance between 2800 and 3000mAh batteries. All the major manufacturers make both versions.

Google for "18650 ragone plot" to find battery comparison charts.

"Leading battery manufacturers focus on a cathode combination of nickel-manganese-cobalt (NMC). Similar to Li-manganese, these systems can be tailored for high specific energy or high specific power, but not both. For example, NMC in an 18650 cell for moderate load condition has a capacity of about 2,800mAh and can deliver 4–5A; NMC in the same cell optimized for specific power has a capacity of only about 2,000mWh but delivers a continuous discharge current of 20A. A silicon-based anode will go to 4,000mAh but at reduced loading and shorter cycle life." - Battery Univ.
 
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Shea N Encinitas

Active Member
Not an experiment I'm going to run any time soon, heck I can average 18 mph, including some big hills, on a road bike. All this speculation and calculation, do you have a bike yet? -S
 

Mike leroy

Active Member
Not an experiment I'm going to run any time soon, heck I can average 18 mph, including some big hills, on a road bike. All this speculation and calculation, do you have a bike yet? -S
No. My road is scheduled for calming soon. The road will become two lane traffic. Want to see what happens to the two decommissioned lanes. My bike decision will be influenced by new road use.

Reducing battery weight to less than four pounds is my goal. I want to incrementally increase battery capacity by connecting 48V, 5 Amp-hour battery modules. I want the flexibility to connect smaller batteries to adapt capacity to the ride demands. Snap three, 5 Amp-hour battery modules together for long, 15 Amp-hour trips. Only carry the lightest battery for short trips to the local store. Polaris batteries are 6 Amp, but not connectable.

I am unsure which battery chemistry/architecture best achieves "snap-in" or "modular" capability. I will investigate and report back.

I want the Pedal Assist System (PAS) to function like motorcycle downshifting. I want max torque (i.e., as differentiated from acceleration/speed) at slow speeds. The controller should only activate the motor when speed drops below weave speed (9mph). The current PAS system is a case of the tail-wagging-the-dog or motor-enslaving-the-battery. Polaris Duo system is based on this concept.

I do not want PAS to simply add a percentage of my leg power -- dumb. I do not want to pay for, nor carry the weight of unnecessary sensors. I need a speed sensor to allow me to cut off power at the most efficient speed for the battery. The controller must be cell phone configurable to allow me to optimize cut-off speed (below 20mph). I need the controller to always display state-of-charge. Laptop computer BIOS handles state-of-charge as a fundamental battery management function very transparently.

I do not want PAS to function like overdrive or turbocharging. Traditional cyclists will have less serious objections to eBikes. Let Gear ratios and leg power achieve high speeds. I do want physical exertion and workout benefits. I run up my hill (10% grade) faster than most cyclists pedal. I pass cyclists at bike weave speed (9mph), when the bike becomes inefficient due to lateral instability.

I do want to conserve the battery consumption to increase battery range. I want hybrid-car-like battery functionality. I do not want yet another energy-guzzling motor. One might call this assist mode "downshifting" , "touring" or "weave" assist mode. Perhaps, "Pedal Assist" is actually a misnomer; best suited for the German Autobahn.

I want the motor RPMs to increase inversely with pedal cadence -- motorcycle downshifting. As I slow down, I want the motor to compensate for my loss of momentum. I do not want overdrive from a high speed. I want to pop the clutch, so the bike lurches forward on a steep hill. Polaris configures motor to gears, so Polaris somewhat approximates this goal.

I do not know how to achieve downshifting. Perhaps, a Polaris gear sensor approach is the most appropriate solution. I contacted Polaris for their suggestions, but their system is fixed. Their
Lithium ion manganese oxide battery chemistry is promising. Polaris philosophy.

I spent over an hour discussing the Polaris Apex with Mike Tumulty, 978-910-0008 x10, mtums@polarisebikes.com . We believe the 100 mile Shasta ride is possible on one battery with careful planning. The key technology is Active Trail, Full Regeneration and Back Pedal regeneration. The bike has climbed 82 miles of Oregon trails with 10% battery to spare.
 
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opimax

Well-Known Member
Mike, if you are reading this, I have no isssues with those post , there are just lots of them, predictable and it made me laugh. you agreed there were many...

my question is why not just take the extra battery and not have range anxiety or power anxiety?I believe i get more in return for the extra effort to carry ( I use panniers) for the ability to save time (go faster), not worry(enjoy my trip more). only down side is expense, batteries and good tires are worth every penny od the extra expense