Right, so it seems as though there is slightly more peril to working on electric/hybrid vehicles than I anticipated. Allowing for the fact that there may be a bit of scaremongering in the mix, there actually are some fairly serious risks, including both DC and AC current, arcing, explosion and chemical spillages.
The two biggest problems are 1) knowing where the high voltage elements (including cables) are located and 2) powering the vehicle down.
The problem with 1 is that no two EVs are the same and the problem with 2 is that no two EVs are the same.
Some vehicles (eg. the Renault Zoe) have the charging point at the front, with high voltage cabling running around the front bumper (one of the main areas we work on), some vehicles have the charging point in a location to the conventional refuelling flap and others have them on the rear. The cables run from the charging point to the batteries (which can be *highly* explosive and shouldn't be exposed to temperatures over 60 C) and from the batteries to the drive unit or units. There is also the question of energy recovery on some vehicles, which adds to the potential for risky cables leading back to the batteries.
Apocryphal stories abound, but in addition to the one above about the PDR tech, we were also told about a youth who wanted to fit neons under his Prius and - in his ignorance - tapped into an orange (HV) cable to power them.
To illustrate the bafflingly casual attitude to safety among manufacturers, attendees on the course were invited to feel inside the plastic sills of the trainer's Peugeot to find - you guessed it - the orange high voltage cables held in place with cable ties.
The only way to be sure where the cables and other elements are located, is to source from Thatcham the "methods" that apply to each version/model/model year of each hybrid or EV. These reveal the location of various elements and routing of cables. Manufacturers, we were told, are unable or unwilling to provide these, for reasons best known to themselves.
The procedure is then to shut the vehicle down. This is something that an EV owner will rarely if ever do; it can be a complex procedure, often involving dismantling assemblies - with some delicate, breakable clips, etc., and physically removing some components, waiting for super capacitors to discharge and repeated, careful testing. It can take 2 hours to power a vehicle down fully. And the keys must be kept at a significant distance, as they can cause the car to power up remotely and without warning.
Once this has been done, the vehicle can safely be worked on (whilst still avoiding putting heat into sensitive areas).
Powering up, as Haynes might say (except that there are no Haynes manuals for this), is the reverse of powering down. However, sometimes this can be complicated and if carried out incorrectly, you can effectively "brick" your customer's £20k+ electric vehicle like a duff mobile phone.
All of this raises some issues:
- an extra 2 hours added to a repair could easily push it into a 2 day job - the EV owner is going to be looking at (yet another) premium.
- what owner is going to entrust their pride and joy to someone who is going to carry out a complex technical procedure that could kill their car just to fix a bumper scuff?
- how happy are our insurers going to be to hear about all this?
But, to me, the most important point is this: If we believe what we are being told, surely manufacturers must do a lot more to improve safe access to vehicles for the purposes of service/maintenance and emergency access (as per JKD's article above.
I cannot see why they should not be legally obliged to fit a shut down switch somewhere on the vehicle that allows the EV to be safely and reversibly shut down. Why is this not already happening?
Oh, and the safety equipment?
An arc shield mask, special 1000V gloves, a set of fully insulated tools for removing and refitting parts, an industrial multi-tester and a bunch of plastic chain and posts to put around the vehicle to keep others away.
A grand's worth? I'm not sure.
However, I think we may well go for it, because unless something happens (like a spate of fatalities, etc), there will be more and more EVs and hybrids on our roads. And now that I know a bit more about them, I won't be working on them until I'm sure they are safe.
NB: I should say that I am aware that many similar caveats could be levelled at internal combustion engines and their highly volatile fuel and potentially lethal electrics.