Voltage of every block
Block by block, plus the gap between the highest and lowest. That is the real measure of battery condition — a single "OK" tells you nothing.
Hybrid battery test before you buy
I check the hybrid battery independently of the seller — on site, at the dealer or outside your home. I read the voltage of every cell block, the spread between them and the hybrid system's error history. You get real numbers before you pay for the car, not a promise that the battery is fine.
We come to the dealer or your home
Every cell block, not just a clean error list
Toyota and Lexus — full data access
Hybrid battery test
from 250 zł
The full price, call-out included, is agreed before I set off. No surprises on site.
Call and book a test
Why it matters
"No fault codes" does not mean the battery is healthy
The most common misunderstanding when buying a hybrid — and the most expensive one.
A basic OBD scan only shows whether the control unit has already raised a fault. A hybrid battery raises one only once the spread between cell blocks crosses the manufacturer's threshold. Until then the car drives normally — while the battery may already be halfway to replacement.
A hybrid battery is several dozen cell blocks wired in series. Its condition is set not by the average but by the weakest block: that one sags first under load and drags the rest with it. What matters is reading each block separately and the gap between the highest and the lowest, not a single summary reading.
Then there is history. The hybrid control unit stores faults and counters over a long period. They show whether the problem has appeared before, whether someone recently cleared the memory, and how the car was used. None of that shows up on a test drive.
- The car drives with no symptoms while block spread is already out of range
- Faults cleared right before the sale — counters still reveal it
- A "refurbished" battery — you can see whether blocks are matched or random
- Blocked battery cooling — a frequent cause of premature wear
Scope
What exactly I read
I connect to the hybrid control unit, not just to the OBD socket for a list of codes.
Behaviour under load
How the blocks hold voltage while charging and discharging. A weak block shows itself in use, not at standstill.
History and counters
Faults stored in the hybrid control unit, including cleared ones, plus system counters. You can see whether memory was wiped before the sale.
Battery cooling
Fan operation and how clear the cooling ducts are. Blocked cooling kills a battery faster than mileage does.
The rest of the hybrid system
Inverter, DC/DC converter and the 12 V battery. Not every "battery failure" is the battery — sometimes it is a cheaper fault next to it.
All other control units
A full scan of the remaining modules comes with it: engine, ABS, airbags, electrics. Already included in the visit.
From our work
What the test actually looks like
A 2018 Toyota Auris Hybrid checked before purchase: voltage of each of the 14 blocks read separately. The spread stayed under 0.15 V even under load and there were no faults — the battery was in very good shape. That is the kind of result you can put in front of a seller.
Toyota Auris Hybrid 2018 · battery test before purchase
Toyota Prius · broken circuit in the steering columnMore real repairs and diagnostics on the AD Garage YouTube channel.
Buying from a dealer? An independent check is normal, not an insult
Around Żyrardów, along the main roads, roughly every third property is a small private car lot. Honest sellers do not mind an independent test — many hand out a diagnostician's number themselves, because a confirmed battery condition makes the sale easier and ends the haggling.
I come to wherever the car is standing. It does not need to be moved or left for a whole day. I work for you, not for the seller — and that is the whole difference from a test run on the scanner that lives at the car lot.
Comparison
The seller's scanner versus an independent test
Same battery, two completely different conclusions.
| What gets checked | Quick scan at the seller | Test by an independent diagnostician |
|---|---|---|
| Faults stored in memory | Yes | Yes |
| Already cleared faults and counters | No | Yes |
| Voltage of each cell block separately | No | Yes |
| Gap between the weakest and strongest block | No | Yes |
| Block behaviour under load | No | Yes |
| Whether battery cooling is clear | No | Yes |
| Who the person testing works for | The seller | You |
How much data is available depends on make and model. On Toyota and Lexus I have full access to block-level battery data — for other makes I confirm the scope before setting off.
How it goes
What the visit looks like
From the phone call to a decision is usually one day.
Phone call
You tell me the model, year and where the car is. I give you the price straight away and say what I can read on that particular car.
Call-out
I come to the address you give — car lot, car park, the seller's home. Weekends included.
Reading
Connecting to the hybrid control unit, reading the blocks, measuring under load, and a full scan of the remaining modules.
Explanation
I go through the result in plain language: what is normal, what is off, and what it means for the price of the car.
Written result
You get the numbers in writing — something you can show the seller while negotiating.
Questions
Common questions about the hybrid battery test
Question not here? Call me — I will answer straight away.
From 250 PLN. The final price including the call-out is agreed on the phone before I set off, so you know the cost before the visit.
Yes. I come to wherever the car is standing: a car lot, a car park, the seller's address. The car does not need to be moved.
Usually 40–60 minutes, including a full scan of the other control units and going through the result with you.
It shows the state of the blocks right now: the spread between them, their behaviour under load and the fault history. From that you can see whether the battery is balanced or already drifting apart — the best warning signal available before a purchase. No test can name a failure date, and nobody honest will promise one.
I have full access to block-level battery data on Toyota and Lexus. For other makes the scope depends on model and year — I tell you on the phone exactly what I will be able to read before we book anything.
You get the numbers and a conclusion. The decision stays yours: walk away, or negotiate the price down by the cost of repair or replacement. A measured report is a strong argument in that conversation.
Yes, their consent is needed to connect to the car — and an honest seller does not refuse. A refusal is itself a piece of information worth weighing.
Yes. You get it written down with the actual values, not as a verbal "it's fine".
See also
Related services
Buying a car? You usually need two things at once.
Check the battery before you pay
One call is enough — tell me the model, the year and where the car is.
Real repairs, not a brochure
I film what I actually do — including the jobs that did not go my way.