1-800-996-6575 Mon-Sat 9am-8pm ET
Search Site

Category Navigation:

You're currently on:

Finance & Lease-To-Own Options ...
Spitfire 1420 Scooter Sale
 EZ Lite Cruiser - Folding Power Wheelchair on Sale
Find Rentals for mobility scooters, power wheelchairs, recliner lift chairs ...
EasyMedOnline BBB ...

Compare Products

You have no items to compare.

My Cart

You have no items in your shopping cart.



Wheelchair Battery Testing / Charging

This works for almost all manufacturers of mobility scooters or electric wheelchairs ...


Q: Do I have a battery problem or a charging problem?

A: The Digital Voltmeter is still the most valuable tool in the Mobility Technician’s arsenal for sealed batteries. The starting point for checking batteries is always the charge voltage. In 24-volt systems we know the chances for two bad batteries are less than 1 in 10,000. So what we need to determine is WHICH battery is bad or if either battery is bad. This is accomplished by checking the voltage of each battery separately.

As illustrated in photo 1, voltage for a pair of batteries can read in excess of 24-volts which can incorrectly be assumed to be a good set. However, as shown in photo 2 one battery has a voltage of 12.89 volts while the battery in photo 3 is reading 11.97 volts. Combined, the voltage of this set of batteries looks good, but clearly the battery in photo 3 is bad.


Two batteries in a 24-volt system charge and discharge together almost as one 24-volt battery. A wide voltage separation between two batteries indicates that you may need to replace both batteries. If both batteries read similar voltage, they should be fully charged before doing any further testing.

If both batteries are below 12.0 volts, the question becomes, “WHY?” Is the battery charger working correctly? Could there be a problem with the wiring or other components of the wheelchair?

You can determine the next step in the troubleshooting process once you know the voltage of each battery.

Q: My batteries were over-discharged and my battery charger will not start. What do I do?

A: Have you ever had a customer state that their batteries will not take a charge even though the charger was plugged in overnight? When you checked their batteries, you found that they both read 9 volts? This is usually due to a light or a brake being left on for an extended period of time, which drains the batteries.

The reason why the charger is not working is that most wheelchair battery chargers need to read at least 21-22 volts in order to begin charging. This is how the polarity protection system of many chargers works. If the user were to hook up the positive and negative backwards, nothing would happen to the charger or the batteries because the batteries never read any voltage so it never started.

The drawback to this polarity protection design is when a user over-discharges their batteries below the 21-22 volt cutoff. Although the charger is connected, it does not receive the signal to begin the charging process so the batteries never get charged.


The best way to solve this problem is to remove the batteries from the wheelchair and charge each battery separately with a 12-volt battery charger. When each battery is fully charged, they can then be reinstalled in the chair and returned to service. Note: It may take the batteries up to 15 cycles to return to their former capacity if they have been severely discharged.

Additional Info ...

Q: How often should I charge?

A: Daily Users:

Charge daily. This applies to anyone who actually uses his or her equipment outside of the home.

Occasional Users: Always be sure to charge before an outing and always after active use. The ideal recharge point is about 50% on a scooter or wheelchair gauge.

Q: How do I charge my MK Batteries correctly?

A: To properly charge your mobility battery, follow these simple procedures:

- Use the manufacturer’s automatic charger for all routine charging.
- Never use an automotive or wet-type charger on gel/sealed batteries. (They’ll quickly ruin your battery).
- Never run your battery completely flat.
- Don’t “top off” the battery with frequent charging.

Q: How should a battery be stored?

A: Always store your batteries FULLY CHARGED.

- Check all batteries once a month and recharge as needed.
- Wet batteries can hold their charge up to 3 months.
- Sealed batteries can hold a charge for up to 6 months.
- When storing a chair or scooter for more than 2 weeks, charge the batteries and then disconnect them.
- Avoid hot and cold extremes when storing.

Q: What is the proper way to store batteries for the Winter?

A: Store batteries fully charged. Check them once a month and recharge as needed. Sealed batteries can hold their charge from 6 to 12 months. Remember, if storing your chair for longer than a couple of weeks, it’s best to charge the batteries and then disconnect them.

Q: I want to store my MK Gel batteries outside for the winter. At what temperature do the batteries freeze at?

A: MK Gel batteries can be stored in sub-freezing temperatures as low as -25°F without freezing as long as they are fully charged prior to storage. The self-discharge rate of fully-charged batteries is so low in these conditions that they will not require charging for many months; however, if your gel batteries are frozen … they will not always recover.

To attempt recovery the following is the best plan of action:

1) Bring them inside and let them sit at room temperature for two days. (They must reach 60°F).
2) Charge the batteries normally. (Follow standard safety procedures).
3) Run a capacity check either through a quality discharge tester or by operating your power wheelchair in a controlled environment.
4) If you don’t get enough run time then repeat steps 2 and 3.

Call EasyMedOnline for help with selecting your wheelchair or scooter battery for models like: Pride Mobility - Go-Go Elite Scooter, Go-Go Ultra X Scooter, Go-Go Elite Plus Traveller Scooter, Revo Scooter, Victory Scooter, Celebrity Scooter, Legend Scooter, Maxima Scooter, Hurricane Scooter, Wrangler PMV. Drive Medical - Falcon, Phoenix, Daytona, Odyssey. Shoprider - Echo, Scootie, Start, Dasher, Sunrunner. Pacesaver - Plus III, Espree / Atlas, Fusion 350/450, Eclipse Premier. Activecare - Spitfire, Pilot, Prowler, Osprey. Zip'r - Zip'r Roo, Zip'r Traveler. EV Rider - Gusto, Vita.

Batteries for electric wheelchair, power wheelchair models: Pride Mobility Jazzy Select, Jazzy Select GT, Jazzy Select 6/7/614/1650/1170/14/600, Jet 3, Go-Chair, Jazzy Traveller, Z-Chair. Pacesaver - BOSS. Invacare - Pronto M51/M91/M51/M61.

Things to Consider When Purchasing Wheelchair/Scooter Batteries...

* Discharge: Gel Cell is preferred for wheelchair and mobility scooter / power wheelchair batteries because of its deep cycle life span. The AGM battery will work nearly as well if the discharge rate is not below 50% before it is recharged.

* Range and Use: A battery's size determines its range. By size, we mean the Amp Hours the battery is rated for. A 30 AH battery has a range of approximately 10 miles, while a 98AH battery has an approximate range of 20 miles. Range depends, of course, on how and where you use your wheelchair or mobility chair and what features it has.