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I once read that batteries don't die, they get murdered - and that dramatic analogy is fitting to AGM/Gel powerchair batteries, where a lack of user attention can result in dismal powerchair performance from the start, leading to compromised mobility over the long haul.  

Fortunately, the opposite is equally true, where users who attentively follow simple battery rules can dramatically increase their powerchairs' performance, all but eliminating ever having battery issues.

1. Recognize Real-World Ranges
Like all energy reserves, powerchair batteries have limitations in how much power they can store and deliver.  Like an automobile's gas tank, the larger a powerchair's battery, the farther it can travel.  As a result, in selecting a powerchair, it's vital to understand the size of batteries that you require per your lifestyle, and realistically how far you can travel.

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Real-world ranges reflect the realistic distance a powerchair may travel per charge (as opposed to ideals listed on many powerchair brochures).  For example, a fully charged, 6.5mph powerchair with Group-24 batteries, traveling around town on reasonably hospitable terrain of sidewalks and sporadic grades, will travel between 14- to 16-miles, at which point it will reach 80% to 90% discharge.  However, range is dramatically affected by individual use.  Maneuvering a powerchair on carpet in a house at low speeds can use two to three times the current draw as a high-speed outdoor run (like accelerating a bike from a stand-still, it takes a lot of power to turn and accelerate a powerchair from a stop).  Similarly, grass, gravel, and other rough, soft terrain can prove taxing on a powerchair's range.  Pay close attention to the conditions under which you operate your powerchair, and know how they affect its range - that is, if you zip around your house all morning, you likely don't want to then try racing 5-miles across town, then back.

2. Know What's In Your Battery Box
While users often understand the battery size listed on powerchair specifications when ordering, it doesn't always guarantee the actual battery size that ends up in one's battery box.  Such specialty seating as a super-low tilt system or elevating seat, based on mounting configurations, can limit battery size, where a powerchair that normally uses Group-24 batteries can be limited to NF22 batteries (which is why it's important to clarify the battery capacity of a new powerchair with specialty seating before ordering).  Additionally, some funding sources will only pay for NF22 batteries, in which a full-size powerchair with a Group-24 capacity could end up being downsized at the provider to NF22 batteries.  As a result, users can believe that they have larger capacity batteries in their powerchairs than they do, resulting in misunderstood range reductions.  For these reasons, when receiving a new powerchair or batteries, always check inside the battery box, if accessible, confirming the battery size that's physically in your powerchair.

3. Respect Your Batteries' Depletion Levels
From day one, battery depletion should be treated with care.  The fact is, drained batteries lead to sulfating and other life-robbing states, decreasing battery performance.  In fact, according to battery researchers, a deep-cycle battery that's only discharged 50% every day, then recharged, will last about twice as long as if it is discharged to 80%.  Now, this doesn't mean that powerchair batteries can't be discharged to 80% when use dictates.  However, if you wish to get the greatest range and life span out of your batteries, try not to dramatically discharge them day after day.


4. Be in Charge of Charging
Without question, proper charging is the most important step in maintaining battery performance.  Powerchair batteries should be charged as soon as possible after each use (again, drained batteries invite issues, where sulfating can begin with 24-hours of a battery's discharge).  Whether you use the powerchair for one hour or sixteen hours per day, charge the batteries each night after use.  

In the charging process, make absolutely certain that your charger is functioning correctly every time you plug in your powerchair - look for the charger's meter to register or for its lights to properly illuminate.  Before unplugging the chair at the end of the charge cycle, always confirm that the charger unquestionably shows that the charge is complete.  Except in cases of urgency, you should never use a powerchair that isn't finished charging.  It's important to note that a charge time of 8-, 10-, or 12-hours is sometimes required for signifigently discharged powerchair batteries, so don't underestimate time needed for a complete charge.  Additionally, do not rely on your powerchair's joystick battery gauge to check if a charge is complete (users sometimes unplug their powerchairs, and glance at the joystick, thinking that there's a full battery charge, when in reality the joystick's battery gauge merely senses a surface charge, incorrectly showing a full charge when the batteries are, in fact, still somewhat discharged - make sure that the battery charger says that the charge is complete).  If you repeatedly don't allow your powerchair the needed time to completely charge, a charging deficit may occur, resulting in less and less range.  Charge your powerchair accurately and completely after every use.

5. Don't Wait Until It's Too Late to Get New Batteries
If you are a daily powerchair user, who follows the above rules, the average life span of your batteries will likely prove 1-1/2 to 2 years.  Obviously, if you witness consistently decreased range - while practicing proper use and charging - you should have your batteries checked and replaced, if needed, as soon as possible.  On the other hand, if your batteries are 1-1/2 or 2 years old, and all seems fine, it's wise to replace your batteries at that point - don't wait until there's a problem. Most insurers fund new batteries annually, and replacing your batteries on a regular schedule will all but eliminate experiencing a sudden drop in range due to failing batteries.

Battery Rules to Live By:

1. Know the size of the batteries in your powerchair, and recognize range limitations.

2. Understand that some uses discharge powerchair batteries quicker than others - be aware of how your uses affect your powerchair's range each day.

3. Don't abuse your batteries by discharging them beyond practical need.

4. Charge your powerchair attentively, correctly, and completely after each use.

5. Replace older batteries before there's an issue.

Batteries can prove among either the least or most reliable components on a powerchair - and the end result hinges upon user awareness. Understand battery characteristics and practice responsible battery use, and you'll dramatically improve the reliability of your powerchair.  

Published 4/06, Copyright 2006, WheelchairJunkie.com