Hybrid car battery test: is it possible, and for which models?
For plug-in hybrids it is, but for regular hybrids it usually isn't yet. Here's where that line is drawn, why a hybrid battery wears out differently than one in a fully electric car, and what a test reveals.
First of all: do you have a hybrid or a plug-in hybrid?
That distinction determines everything, and many people don't know it about their own car. The rule of thumb: can you plug it into a socket or charging station? Then it's a plug-in hybrid. If you can't, then it's a regular hybrid, also known as a self-charging hybrid.
The difference lies in the battery. A plug-in hybrid has a battery pack of roughly 8 to 25 kWh, which is large enough to drive on electric power for a while. A standard hybrid has one of about 1 kWh, which only captures braking energy and assists the engine during acceleration.
Hybrid
No plug. Battery pack around 1 kWh, only for regenerative braking and assistance when accelerating.
Testing: not yet
Plug-in hybrid
It does have a plug. Battery pack from 8 to 25 kWh, good for a decent amount of electric driving.
Tests: yes, over 170 versions
Fully electric
Plug-in only. Battery pack from 20 to over 100 kWh, the sole powertrain.
Testing: yes
What we do and do not test
We test plug-in hybrids as standard, just like fully electric cars. Our list includes over 170 plug-in models from 31 brands, ranging from Audi and BMW to Toyota, Volvo, and Mitsubishi. For some of them, results are available instantly; for others, within 36 hours.
We cannot yet broadly test standard hybrids. Four models are on the list — Toyota Auris, Toyota Yaris, Renault Austral, and Renault Symbioz — and all four are still in development. If you are unsure about your specific model, please check the list of supported vehicles.
Why a plug-in battery degrades differently
A plug-in hybrid has a small battery pack that is frequently fully charged and fully drained. A fully electric car with a large battery pack goes through far fewer of those complete cycles for the same mileage. As a result, a plug-in can suffer from more battery degradation than an EV at the same mileage.
On top of that, a plug-in hybrid runs on its combustion engine more often with an empty battery, leaving the pack warm without being used. Mileage therefore tells you even less about the battery with these cars than with an EV. Only a test will tell you the real story.
What the test yields
The same outcome as with an electric car: a SOH percentage, the voltage per cell, the charging behavior, and the temperature distribution, recorded in a certificate linked to the VIN. The measurement takes three minutes, and there is no need to open up the car.
Cell balancing is especially interesting for a plug-in. Because of the frequent full cycles, cells drift apart sooner, and you can see this long before the percentage itself becomes alarming.
What it costs
A hybrid doesn't cost more than an electric car. There are two ways: you can have the test done, or as a car company, you can measure it yourself using the TBE Toolkit.
Private: € 80 including VAT per test, with us in Blaricum or at an affiliated garage.
Business: € 29.95 excluding VAT per test.
TBE Toolkit, dongle only: € 59 excluding VAT.
Toolkit with one adapter cable: € 99 excluding VAT.
Complete set: € 299 excluding VAT.
Which adapter cable you need depends on the brands you service in the workshop. Tesla, for example, requires a brand-specific cable.
Frequently asked questions about the hybrid battery test
Can a standard hybrid be tested?
Not widely yet. Four models are on our list, but are still under development. We do test plug-in hybrids: over 170 versions from 31 brands.
How do I know if I have a plug-in hybrid?
If you can plug the car into a charging station or wall socket, it's a plug-in hybrid. If you can't, it's a standard or self-charging hybrid.
How much does a battery test for a plug-in hybrid cost?
The same as for an electric car: €80 including VAT for individuals, €29.95 excluding VAT for businesses.
Does a plug-in battery degrade faster than an EV battery?
At the same mileage, often yes. The battery pack is smaller and undergoes full charge and discharge cycles more frequently, which matters more than the distance.
Is your version on the list?
Look up your make and model to instantly see whether the test provides results immediately or within 36 hours.