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If you've used a powerchair for some time, you've likely heard or pondered the ultimate powerchair mythos, that there must be a deep, hidden level of programming parameters within electronics that have the potential to dramatically increase the torque and speed of a stock powerchair beyond what manufacturers allow.

The "hidden programming" theory has been around for decades, but it's been in recent years where the Internet has brought the belief to mass exposure, with the theory discussed as fact on disability-related web sites and message boards.  Maybe you've encountered it, where a seemingly all-knowing user opens up a realm of possibilities with first-hand knowledge of deep-seated, veiled powerchair settings that are accessible only by high-security programmers, ones so sensitive that neither consumers, providers, nor wheelchair manufacturers have them.  Yet, for those who have infiltrated the secret society of powerchair programming, they can alter a series of settings that will give a stock powerchair enough torque and speed run circles around all others.  

How true is this thesis - after all, powerchairs have complex electronics, and a talented person must be able to reprogram the controller in ways that the layman doesn't know, dramatically increase a chair's performance beyond what manufacturers presume end-users comprehend, right?

The Basics
To fully explore the theory of using deep programming to increase a powerchair's performance potentials, let's start with a few basics:  In the area of torque, the controller provides the current (amperage), demanded by the motors, generating torque at the wheel.  If a powerchair runs on flat, smooth ground, the motors my only demand 20 amps from the controller; however, on a hill, the controller may be required to deliver 50 amps, meeting the motors' demands, supplying the current needed to increase the power output at the wheel in order to climb the hill.  The more amperage that the motors can draw from the controller, the more torque that the motors and gearboxes can ultimately produce.   With these principals, the way, then, to increase torque is through allowing additional amperage draw from the controller.

The Potentials
Moving on to actual components, powerchair controllers are engineered, rated, and marketed by their peak amperage potential, commonly 50-, 80-, and 100-amp systems.  This peak amperage is the maximum amount of current that motors can draw from the controller to create torque.  The maximum controller amperage is usually allowed on the end product that consumers use - meaning, if your powerchair has an 80-amp controller, it can realize 80 amps in everyday use, if conditions demand.  Controllers, then, are manufactured and used within the full range of their maximum potential, not limited by programming.  An 80-amp controller can only deliver 80 amps - that's the peak current, period.  Therefore, as a controller in most cases is already engineered to reach its potential on a production powerchair, it cannot be programmed to supply the motors with any additional torque.

While a powerchair's electronics dictate the maximum current as relating to torque, they don't dictate the maximum potential speed of a powerchair - that's a function of the motors, gearboxes, and voltage.  It is true that you can program electronics to limit the top speed that a chair achieves, but you can't program a speed beyond the maximum speed potential of the motors and gearboxes.  For example, if motors and gearboxes are engineered to propel a particular powerchair at a maximum of 7mph, the controller will allow 7mph when programmed with a max speed of 100.  If one turns down the speed's programming, say to 90, the chair's speed is then less than 7mph, accordingly.  In this way, a controller is designed to allow maximum motor speed potential, or limit a powerchair's top speed.  A controller can't, however, override the motors' maximum potential speed to make the powerchair travel faster.  Furthermore, even if additional voltage were applied to the system - which would, in principal, increase motor speed - powerchair controllers won't allow it, limiting top speed voltage to 22.5 and 23 volts.  As such there's no way to increase a powerchair's speed via programming beyond the maximum potential of the motors, gearboxes, and voltage.

With component maximum potentials explained, some might wonder if powerchair manufacturers ever sell products programmed with the current level and speed parameters set below the maximums?  For example, do manufacturers ever take a 100-amp controller and 8.5mph motor package and turn it down via programming to 50 amps and 5mph?

Typically, no.  Component costs are of considerable importance in the manufacturing of powerchairs just like they are with most other products - and high-amperage electronics and large, high-end motors add cost - so adding materials expense with maximum performance potentials that aren't needed, used, or advertised goes against business fundamentals.  In this way, a manufacturer couldn't economically compete by putting high-performance drive systems on low-end powerchairs, then limiting performance through programming.  Additionally, in the high-end marketplace, torque and speed are competitive points, where the competition of balancing torque and speed is fierce, so a manufacturer has no interest in watering down performance at any level.

The Facts
When one equates that the standard controllers and motors on most powerchairs are set up to achieve maximum potentials, and that powerchair manufacturers don't typically turn down parameters to prevent optimal torque and speed potentials, it becomes clear that there's no such aspect as hidden programming to increase a powerchair's performance.  No matter a 5mph light-rehab powerchair, or an 8.5mph high-end powerchair, most products run up to their maximum potentials from the factory, with no way to increase torque or speed beyond the maximum parameters dictated by the physical components.

The Mythos
Still, the mythos of hidden programming parameters exists, a belief pattern stemming from misunderstanding and wishful thinking.  Undoubtedly, if one is unfamiliar with powerchair electronics, and a provider raises a parameter setting like Acceleration from 35 to 80, the user is bound to be impressed, noting a seeming increase in torque at take off.  However, in reality, the powerchair's maximum torque potential hasn't changed in the least; rather, what has changed is the response time of the powerchair in reaction to joystick movement - the powerchair simply takes off quicker, getting to its maximum speed in a shorter amount of time (just as stomping the accelerator pedal of a car seemingly gives it more "power," but it's really just changing the speed at which the car accelerates to its motor's maximum potentials).  In this way, it's understandable how users could perceive increased "liveliness" as increased torque when the maximum torque potential truly remains unchanged.

There remain, however, users on the web, claiming to know the depths of powerchair programming far beyond everyone else, proclaiming that they know of the secret programming hardware and hidden parameters that dramatically increase a powerchair's performance beyond the "seeming" maximum potentials that most are lulled into believing.  This social practice ties into wishful thinking.  After all, even the best mobility products are limiting - as disability, itself, is limiting - and believing or proclaiming that one knows a secret way to make ordinary mobility products extraordinary offers up a subtle sense of hope and inspiration, even if it is false.  

The Realities
Ultimately, I'm always looking for maximum performance in mobility products, and if there was a way to truly increase my own powerchair's torque and speed beyond the present component maximum potentials at the touch of a top-secret programmer, I'd do it, myself, and manufactures would, too.  The reality is, I run the same sort of 100-amp system as a host of chairs on the market today, with the same factory programming parameters, with the same maximum potentials.  And, my powerchair is set-up remarkably similar to most, for one very good reason:  Until someone can override the principals of mathematics and the laws of physics, it's impossible to use programming to make a powerchair perform beyond its maximum component potentials.  

I declare the theory of hidden powerchair programming potentials a mobility mythos - busted.    


Published 11/05, Copyright 2005, WheelchairJunkie.com