Buying a used electric car? Watch out for this, or you could lose thousands of euros
The used car market is going through a quiet revolution. More and more electric cars and plug-in hybrids from their first or second owner are appearing on the roads and in dealer listings. For many drivers this is a tempting opportunity to step into the world of quiet, eco-friendly driving at a fraction of the price of a new car.
When buying a conventional diesel or petrol car, most people already have a proven routine: they check the paintwork, engine leaks, brake condition and suspension, and use trusted registers such as Vinpie.com to verify the mileage history, service records and insurance claims.
With an electric car, however, the situation is completely different. The most important and most expensive part is entirely hidden from the human eye. Read on to learn what you absolutely must do when inspecting a used electric car, so that your dream come true does not turn into a financial nightmare.
The heart of an electric car determines its price
Imagine buying a used car whose engine is worth half of the vehicle's entire value. That is exactly the case with electric cars. The traction battery accounts for 30 % to 50 % of the car's total price. While replacing brake discs or shock absorbers is a matter of a few hundred euros, a new EV battery can cost you 8 000 €, 15 000 € or, in the worst case, even more than 20 000 €.
Everything else on an electric car – from the electric motor through the chassis to the interior – shows minimal wear compared to cars with combustion engines. Electric motors are structurally simple and almost indestructible. Thanks to regenerative braking, the brakes wear out much more slowly.
The key to a successful purchase therefore lies in a single place: the health of the battery (the so-called SoH – State of Health).
Three questions you must ask the seller
When you are standing next to the car you have your eye on, you must not settle for an answer like: "The car runs great and the battery holds up." Demand facts. Ask:
1. At what percentage did the car usually sit parked, and how often was it fast-charged?
Lithium-ion batteries suffer most from two things: extreme heat and long periods spent at extreme states of charge. If the owner regularly charged the car to 100 % and left it sitting like that, or frequently charged it at DC fast chargers, they significantly accelerated the battery's degradation. Conversely, the ideal scenario is a car charged by a family at home from an ordinary wallbox (AC charging) within a range of 20 % to 80 %.
2. Is the battery still under the manufacturer's warranty, and under what conditions?
Car makers typically provide a longer warranty on batteries than on the vehicle itself – usually 8 years or 160 000 kilometres. There is a catch, however. The warranty generally only applies when the battery capacity drops below 70 %. If the car has 71 % capacity after 6 years, the manufacturer will replace nothing free of charge, even though the car's real range on a single charge is already almost a third shorter.
3. Can I see an independent battery health (SoH) certificate?
This is the most important question of all. If the seller shakes their head or only shows you the display on the dashboard, be on your guard.
Warning: the number on the dashboard can lie
The most common mistake newcomers make is looking at the car's instrument panel, where the battery state (SoC – State of Charge) shows 100 % and the range reads, say, 300 km. They think: "Great, the battery is full and the car will go far enough."
But beware – the current charge level has nothing to do with the battery's health! Even a battery that is severely degraded, with a real health of 71 %, will happily charge to "100 %" on a charger. On top of that, the range indicator on the dashboard calculates the distance based on the most recent drives. If someone drove the car slowly downhill through town with a large share of regenerative braking before the viewing, the on-board computer will optimistically show you a range you will never achieve on the motorway in winter.
The solution? Don't guess – measure
Buying a used electric car without a precise battery diagnostic is like buying a conventional car without ever starting the engine.
Before buying, therefore, always insist on an independent battery verification (SoH certification), or simply run the test yourself using our service. Our modern diagnostic platform works by connecting directly to the battery management system (BMS) and measuring the actual voltage of the individual cells, the maximum temperature, the exact amount of energy that has flowed through the battery over its entire life and, above all, the battery's SoH.
Our independent test will tell you precisely: "This battery's health is 87 %." You then know exactly where you stand. You gain not only the certainty that you are not buying a pig in a poke, but also a strong argument for negotiating the final price of the car.
The investment in a battery test is a fraction of the amount compared to the risk of having to invest thousands of euros in a new battery pack a few months later. With electric cars, the old saying applies twice over: trust, but certify!