SECTION
Field Load Test
NOTE: For this procedure, refer to FIGURE 3.1 on page 29.
NOTE: The following test can also be performed through the controller of the wheelchair along with a remote programmer. Refer to the electronics manual, part number 1114808 supplied with each wheelchair.
Old batteries lose their ability to store and release power, due to increased internal resistance. This means that as you try to take power from the battery, some of that power is used up in the process of passing through the battery, resulting in less voltage at the posts. The more power drawn, the lower the voltage available. When this lost voltage drops the output 1.0 volts under load (2.0 for a pair), replace the batteries.
To spot this problem, test batteries under load.
Use a digital voltmeter to check battery charge level at the charger connector. It is located on the joystick.
NOTE: READ these instructions CAREFULLY and the manufacturer’s instructions on the digital voltmeter before using the digital voltmeter.
NOTE: Invacare recommends that ONLY a qualified technician perform this test.
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 one.
3.Remove the footrests from the wheelchair
4.Connect the voltmeter leads to the charger port 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 25.5 to 26 VDC.
WARNING
When performing STEPS 5 and 6 ensure feet are clear from casters and wall otherwise injury may result
5.Sit in wheelchair and place feet against a wall, workbench or other stationary object.
6.Turn the power ON and carefully push the joystick forward, trying to drive the wheelchair through the stationary object.
NOTE: This 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.
7.Read the meter while the motors are straining, no longer than
NOTE: If the voltage drops more than 2 volts from a pair of fully charged batteries while under load, they should be replaced regardless of the unloaded voltages.
Pronto® M71™ | 28 | Part No 1118377 |