In this section I want to share with you some knowledge on hybrid and electric vehicle safety.

I recently attended a 1 day training course with TDN to obtain my IMI accreditation. I want to share with you some of what I have learned to help guide you but please be aware this will be a information only so if you do intend to work on Electric vehicles my recommendation is to attend an IMI course yourself.

This year Tesla is the fourth best selling car in USA so no doubt about it they are becoming more and more common, in 2013 there were an estimated 1.8M hybrid vehicles, that's 2.9% of the market. Now in 2021 there are estimated to be 9.8M on the road and that's 14% of the market so huge growth.

Categories of High Voltage Vehicles

Hybrid Electric Vehicle (HEV)

- A vehicle powered by two or more energy sources and convertors one of which is electricity, the term hybrid may include micro hybrid technology such as 'stop start' systems.

Plug in Hybrid Electric Vehicle (PHEV)

- Hybrid vehicles that can charge their batteries from an external source in the same fashion as electric vehicles.

Extended Range Electric Vehicle - (EREV)

- An electric vehicle equipped with an electrical generator. A small combustion engine that operates solely to provide electricity and not to propel the vehicle

Electric Vehicle (EV)

- A vehicle powered by energy solely stored in an electrochemical device, generally electricity provided by batteries, an EV is not a hybrid vehicle

Components that make up the High Energy Electrical Drive Train

High Voltage Battery

High voltage system cables

DC/AV DC/DC invertor convertor

E-Machine (AC motor)

Air conditioning system

Battery Risks

Explosion - Overheating, charge faults

Fire - Overheating, piercing, charge faults

Leakage - Piercing, charge faults

*If a leakage is detected identify using litmus paper, if found to b alkaline (NiMH) neutralise using boric Acid solution

Regulation Classifies 'High Voltage' as being a working voltage of

>60v - <1500v DC (Direct current)

>30v - <1000v AC (Alternating Current)

Amperage

Anything over 50mA can be enough to Kill!

High Voltage Power System Hazards

Components that present a high voltage hazard are - battery, system cables, invertor/convertor, e-machine and air conditioning system.

Any external visible high voltage wiring and connectors will be coloured orange, medium voltage will be coloured blue.

HV cables can be found running front to back of the vehicle DC and 3 phase cables between invertor/convertor to the e-machine and air conditioning system

Personal Protective Equipment (PPE)

Insulated gloves, minimum category rating is 1000v Cat 0, a cotton under glove should be worn as well, test/inspect all PPE prior to use, generally you should cordon off an area and make it visible with barrier tape so that no one comes in to your area whilst you are working, a rubber mat with the correct category rating can be used to stand on whilst disconnecting the system and the 'one hand rule' used when contacting any part of the HV electrical circuits, remove all jewellery such as rings, watches, bracelets etc, use appropriate PPE and always assume orange cables carry voltage levels above 60v until proven otherwise. Keys should be kept in a secure location (ideally in a locked box) at least 16 feet away from the vehicle being worked on.

The one hand rule is a simple one, whilst it is logical to use both hands if you were to get a charge it would travel through one arm across your chest and down the other arm, this is pretty much inline with your heart so don't do it! Although using one hand would still give you some serious burns and shock, it is less likely to be fatal.

Never carry out work on a PHEV or EV vehicle whilst the vehicle is plugged in on charge!

Only work on high voltage systems if you have the correct qualification and never work alone

There is an App you can download to assist you in identifying the procedures, jacking points, component location and how to jump start - 'Pro-Assist Hybrid'

EV and Hybrid vehicles

Training

Bodylines

Resources

Repair Examples

Knowledge Checker: Step 4 - Working on Door Panels & Restoring Bodylines