Whilst EV numbers are growing strongly the big volumes for servicing at the moment are hybrids with a lot of NZ new Hybrids and Used imports in the NZ car parc.
In 2023 new sales included almost 30,000 hybrids (close to 20 per cent of the market) plus another 9,000 PHEVs and 21,500 EVs meaning over 40 per cent of new vehicles sold had a form of electrification, this will start to represent the mix of vehicles arriving at your doors over the coming years.
A lot of the servicing is still the same, especially with hybrids and PHEVs which have all the normal car running gear (engine, transmission, suspension and all the interior), even full EVs still have normal suspension and brakes, air conditioning and electronics.
The new bits for servicing are the EV motors and generators, motor control systems and batteries plus their ancillaries.
With the right equipment and training workshops can easily get into EV repairs. Some basic equipment would include barriers to isolate the EV vehicle during repair, insulated gloves and some insulated tools. Modern Scan tools usually include some Ev diagnostic functionality. More major repairs may require specialist outwork or in the case of older vehicles a good option could be replacement with parts from a dismantler.
At the recent AAAE Expo in Australia we attended an EV repair training taster session, this was focussed on diagnosing issues with the motor/generator units from recent Toyota hybrids (Camry/Prius/Corolla) where there are now quite a few older vehicles in the fleet. This was only a taster covering the basic steps but was designed to show that it is not as difficult as most expect it to be, if you wanted to do this type of work a more detailed course would be recommended.
It started with a reiteration of the safety messages such as isolating the traction battery, being aware that pushing the vehicle around the workshop can produce dangerous high voltages from the motor/generator and then looked at some steps to diagnose motor/generator faults.
The Toyota Hybrid units used in the session consist of a two motor generator units MG1 and MG2. MG1 is smaller and acts as starter motor and a generator to charge the battery whilst MG2 provides the drive. These motors have similar construction to industrial three-phase motors and consist of three sets of windings spaced at 120 degrees. Testing looks at all three phases. Initial testing can be done using a Megger tester or DAR tester which checks for insulation breakdown in the winding (DAR test – Dielectric absorption ratio).
The next test was using a milliohm meter to measure current as the motor was manually turned (either by hand if out of car or via a jacked up wheel if in the car) – you can compare the output of the three phases, the instructor likened it to an ICE engine compression test in that you are looking for variation rather than any absolute values with no more than five per cent variation being ideal. Lastly they showed off the fully automated All Test Pro 34 that runs through a suite of test including the above and provides an onscreen report. Whilst the previous test equipment was affordable for individual workshops the All Test runs around AUD $17,000 so might be something that a group of workshops share unless you are likely to have high use.
It was interesting that the testing was less complicated than we imagined and is something any technician could learn with suitable training and can be accomplished with affordable equipment.
