Car Features

We’ve been asked by many Historic Vehicles website followers about the viability of converting their classic cars to battery-electric power and we’re indebted to the Australian Electric Vehicle Association for input into the realities of BEV conversions. 

Lunaz Conversions

For those who are time-poor and can’t wade through the following facts, it’s safe to say that converting your classic vehicle to a BEV may not be a good idea: either from the up-front cost point of view, or from the likely effect on its resale value.

“We certainly don’t want to discourage you, but converting a former ICE vehicle to electric is not for the faint of heart,” said the AEVA advice article.  

“Mechanical and electrical work requires that the vehicle be built to a high standard.  

“Many parts will be custom-made and might take several iterations to get right.  

“Trying to fit electric components in a vehicle made for an in-line engine means compromises will be made.”

Electric GT Conversions

It’s easy to be wooed by on-line ERV conversion kits that start around the eight-grand mark, but these kits don’t include batteries and several other vital components you’re going to need. In addition, there’s no guarantee that cheap kits will work well, or that the converted vehicle can be road-registered.

Our independent research at HV indicates that, as at 2024, the typical real-world, legitimate and rule-compliant BEV conversion cost is a rock-bottom minimum of $40,000 and much more likely to exceed $60,000. We know of several that have crested the magic $100,000 point.

We did an assessment when our classic LandCruiser 75 Series was in desperate need of a heart transplant and discovered that a complete 1HZ -T diesel engine rebuild – to blueprinted, as-new standard – would set us back around 27 grand, including labour and the obvious additions of new clutch, radiator and fan assembly. 

We discovered that we couldn’t do a BEV conversion for less than at least treble that figure, if we wanted reasonable performance and around 400km operating range. Most conversions use the common metric: ‘100 at 100’ – a range of only 100km, when travelling at 100km/h and that was of no use to us. 

The AEVA points out that: “converting a car or motorcycle to electric drive is perhaps best left for … classics, for which spare parts are impossible to source.”

AEVA photo

In one way, the older the classic, the less complex it is and the simpler should be the conversion. For example, an old machine that has no HVAC at all, cable brakes, manual steering and very few electrical components is much easier to convert than one with a vacuum brake booster, hydraulic power steering, an HVAC system and complex electric and electronic circuitry.

Check out this diagram of Chevrolet’s eCrate kit for retrofitting to its US pickup range. There’s more to a conversion than simply swapping out the ICE for an electric motor that’s usually one of the cheapest components.

Practicalities

The AEVA’s suggested procedure is the start with a vehicle that has minimal rust, good brakes and ample chassis space to accommodate batteries. 

“Battery packs add significant weight to a vehicle’s tare, so you might need to upgrade the suspension as well,” said the AEVA. 

We’d add a cautionary note to this critical point: you may need a gross vehicle mass (GVM) upgrade if the projected total weight of the vehicle exceeds the original maker’s maximum GVM. Old axles, wheels and tyres may not be able to handle the additional weight.

“Range is always a compromise – more range means more weight and, of course, more money,” said the AEVA.  

“You will mainly be limited by what can physically fit inside the car without overloading it.

“If you only plan on commuting fairly short trips, save time and lots of money by opting for a smaller battery pack.”  

AEVA photo

On the subject of what electric motor to choose there’s need for great caution, because electric motor power and torque delivery is quite different from internal combustion engine (ICE) behaviour.

In addition to running the HV website we have the Outback Travel lAustralia site and, until recently, did truck reviews for the Trucksales website. As a result we get to drive many new SUV BEVs and ICE-electric hybrids, as well as BEV heavy trucks. We’ve observed that their torque delivery is massive and instant: constant peak torque from zero revs is something ICE drivers can only dream about.

The downside of that is high torque being fed into the existing transmission and that may prove to be too much. Some conversions remove the gearbox entirely. Also, the original final drive ratio may no longer be appropriate, dictating yet another modification.

Legalities and safety

Before starting any electric conversion it’s vital to have approval from lawmakers. The Commonwealth Department of Infrastructure has a list of Vehicle Standards Bulletins, with National Codes of Practice for specific aspects of vehicle function and safety.  

The AEVA was instrumental in formulating NCOP14 – Guidelines for Electric Drive – that sets out minimum expectations and standards of work to be done, and is the standard to which your conversion will be assessed by a certifying engineer.  

Unlike ICE-powered vehicles BEVs have battery packs that operate at potentially lethal voltages.  Also, many conversions don’t have sufficiently advanced battery thermal management systems and many EV fires have been traced to poor thermal management. 

A similar dangerous situation can be caused by an inadequate battery management system (BMS).  As Li-ion cells have a maximum and a minimum operating voltage, as well as temperature limits, exceeding these limits by either over-charging, or over-discharging the battery, will cause irreversible damage and potentially start a fire.  

On-board battery chargers also need to be thermally controlled.

Battery installations are now covered by a new Australian Standard and need to be much more secure than previously allowed. The old days of batteries stowed, exposed, under the caravan bed are gone!

Certification

“Certifying engineers will want very detailed wiring diagrams and photos of the build process, as well as the new weights and weight balance,” said AEVA.  

“Build logs on the AEVA forum are perfect for documenting the history of your project and providing a timeline of changes for the engineer.” 

Engineers also carry out braking tests, before submitting their reports to the relevant transport authorities. 

The AEVA is happy to provide advice on any EV conversions.

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