Field Load Test - Invacare Pronto M41 Service Manual

Field Load Test

NOTE: For this procedure, refer to FIGURE 3.1 on page 28.
Old batteries lose their ability to store and release power due to increased internal
resistance. In this procedure, batteries are tested under load using a digital voltmeter to
check battery charge level at the charger connector. The charger connector is located on
the joystick. When voltage at the output drops 1.0 volts under load (2.0 for a pair), replace
the batteries.
NOTE: Read these instructions carefully and the manufacturer's instructions on the digital
voltmeter before proceeding.
1. Ensure that power is Off.
2. Make sure battery is fully charged. An extremely discharged battery will exhibit the
same symptoms as a bad battery.
3. Remove the footrests from the wheelchair. Refer to Front Riggings/FootBoard on
page 44.
4. Connect the voltmeter leads to the charger connector on the wheelchair as shown in
FIGURE 3.1. Most digital voltmeters are not affected by polarity, however, analog
meters (meters with swinging needles) can be and should be used carefully. A good
meter reading should be 25.0 to 25.8 VDC with the chair in neutral.
When performing the remaining steps, ensure your feet are clear from casters and
wall, otherwise injury may result.
5. Run the wheelchair in neutral for at least 2 minutes.
6. Sit in wheelchair and place your feet against a door jam, workbench, or other
stationary object.
7. Carefully push the joystick forward, trying to drive the wheelchair through the
stationary object. The load should draw between 30 to 40 amps from the batteries for
0.3 seconds.
NOTE: Performing STEP 7 puts a heavy load on the batteries as they try to push through the
stationary object. If the wheels spin, have two individuals (one on each arm) apply as much
downward pressure as possible on the arms of the wheelchair.
8. Read the meter while the motors are straining to determine the voltage under load.
NOTE: If the voltage drops more than 2.5 volts from a pair of fully charged batteries during the 0.3
seconds, they should be replaced regardless of the unloaded voltages.
Part No 1145724
SECTION 3—SAFETY INSPECTION/TROUBLESHOOTING
WARNING
27 ®
Pronto M41