Plug-in hybrid vehicle (PHEV) owners often live with the idea that battery life is universally good. However, a new, large-scale study by the prestigious German automobile club ADAC, covering 28,500 PHEV models, throws down the gauntlet: the differences in degradation between brands are striking, with some premium manufacturers leading convincingly while others prove to be a serious disappointment.
Mercedes-Benz - endurance champion
If you are looking for security and minimal capacity degradation, look to Stuttgart. Mercedes-Benz models demonstrate enviable resistance to the test of time and mileage. According to ADAC data, even after an impressive 200,000 kilometers, the average battery capacity retention remains around 90%. This result is even more impressive when you consider that the intensity of driving in electric mode had almost no negative impact on the battery condition.
BMW, Volvo and Volkswagen - predictable stability
The Bavarian competitors - BMW, show a more noticeable, but still predictable, loss of capacity. With the same mileage of 200,000 km, the capacity varies between 77% and 90%, with an average value of over 85%. This is a stable, although not record, result.
The Volvo and Volkswagen models also fall into the category of "normal" aging. Even with frequent and intensive use of electric mode, these PHEVs maintain a capacity of over 85% after 200,000 km, which speaks of reliable thermal management and intelligent electronics.
Mitsubishi and Ford - big losers
Unfortunately, other brands are lagging behind. Ford shows a serious 10% drop in capacity after just 25,000 km, especially in cars that have been actively driven in electric mode. Although due to the small sample size, ADAC cannot give a definitive assessment of higher mileage, this initial decline is a serious cause for concern.
However, Mitsubishi turns out to be the biggest disappointment of the study. Their hybrids show more than a 20% loss of capacity over 100,000 km and a startling 25-30% drop over 200,000 km. ADAC emphasizes that this significant aging is registered even in models that have rarely been driven in electric mode – a clear signal of poor battery management.
How to extend the life of lithium-ion cells?
The expert advice for preserving battery longevity is familiar: avoid frequent full charges (up to 100%) and deep discharges (below 20%). The recommended "golden" charge range remains between 20% and 80%. Excessive use of fast direct current (DC) charging, which some hybrids support, is also considered a harmful practice.
ADAC recalls that despite the presence of heating and cooling systems in car batteries, they cannot radically outlive their lithium-ion counterparts used in mobile gadgets, whose lifespan rarely exceeds a decade.
Advice before buying: Check with a scalpel
Before settling on a used PHEV, experts are categorical: it is imperative to check the condition of the battery. As a general guideline, ADAC recommends the following minimum values for retained capacity:
50,000 km - at least 92%;
100,000 km - at least 88%;
150,000 km - at least 92%;
at least 84%;
200,000 km – at least 80%.