The Hird Test – measuring MEWP battery endurance
Hird has developed an operational test for testing the battery performance of DC electric mobile operating work platforms (MEWPs) that has been taken up across the world.
Manufacturers, in particular, were quick to adopt the Hird Test to ensure claims for operational performance could be substantiated and to benchmark their MEWPs against competitor machines.
Peter Hird Snr, the founder of Peter Hird & Sons, as the company was then called, developed the test in the late 1988s, after a customer complained about the poor battery performance of a machine.
The Hird Test involves repeatedly putting a fully-charged machine through a standard set of manoeuvres, known as operational cycles, until it runs out of power.
A Hird Test was first developed for self-propelled electric articulating booms and then for self-propelled electric scissor lifts.
Since then, Hird has been contacted regularly by manufacturers and operators keen to incorporate the test into their product development, manufacturing, and MEWP maintenance programmes.
- Select a clear and smooth concrete or asphalt area, indoors or outdoors. Note: asphalt may reduce battery performance, especially in hot conditions.
- Mark out the test area as per the diagram.
- Make sure the machine is fully-charged over-night before beginning the test.
- Complete all pre-use checks before beginning the test.
- Place the machine at position A.
- Drive the machine in its folded position, allowing it to reach its maximum speed, to position B and then back to position A.
- In position A, extend each boom section individually until the machine reaches full elevation.
- Telescope out fully until the boom is at maximum reach height.
- Slew the basket 900 then back into its original position.
- Retract the telescope.
- Retract each boom individually until the machine is in its stowed (fast travel) position. That is the completion of cycle 1, which should be recorded.
- Repeat steps 1 to 11 until there are any signs that the machine is closing down.
- Select a clear and smooth concrete or asphalt area, indoors or outdoors. Note: asphalt may reduce battery performance, especially in hot conditions.
- Mark out the test area as per the diagram.
- Make sure the machine is fully-charged over-night before beginning the test.
- Complete all pre-use checks before beginning the test.
- Place the machine at position A.
- Drive the machine to position B, allowing it to reach its maximum speed, crossing the centreline between the two traffic cones to activate the steering motors.
- At position B, lift the platform to its full height and stop.
- Lower the platform to its travelling position. That is the completion of cycle 1, which should be recorded.
- Drive the machine back to Test Position A, allowing it to reach maximum speed, crossing the centre line between the traffic cones to activate the steering motors.
- In position A, lift the platform to its full height and stop.
- Lower the platform to the travel position. That is the completion of cycle 2, which should be recorded.
- Repeat these steps until there are any signs the machine is closing down.
Additional information
- Periodically check the battery condition meter.
- Record the cycle during which the battery light comes on.
- Continue the test but stop at the first sign that the machine is closing down.
- A second person should be present on the ground to monitor the progress of the test and activate the emergency lower if necessary.
Boom Lift and Scissor Lift
Do not fully discharge the batteries during this test, as this may cause damage to the batteries.
Scissor Lift only
If the platform is fitted with an anti-trap system that stops the machine from lowering momentarily, do not activate the emergency lower function from the ground control in any other way. Continue to operate the machine from the upper controls at all times.
Note: the Hird Test is carried out at the discretion of the person performing the test. Hird accepts no responsibility for any tests undertaken. This test is designed as a guide.