HV Battery State of Health (SoH) - what to ask before buying

[LondonCarGuy]

ted 191 said:

My 296 has been sat at the dealership for nearly 3 months, awaiting rejection.
On top of the problems I ve had, whilst in the care of a main dealer, the car has been regularly charged via the 400 volt battery, the 12 volt battery has now depleted to 10.9 volts and it has gone into limp mode three times ..without turning a wheel !

I think so many hybrid cars are poorly cared for at Ferrari Dealerships in the UK. I visited one Ferrari Dealer who had approximately six 296s for sale outside in the cold rain, only one was plugged in. Even the salesman said to me, "gee, maybe we should plug these in?" Yes, mate, maybe you should.

I'm really sorry you guys had to get the cars rejected.

[LondonCarGuy]

This is not really applicable to high performance hybrids like Ferrari and Lambo, but still offers some stats for normal PHEVs:

https://www.topspeed.com/how-phev-batteries-from-d...

[LondonCarGuy]

Chrisatronic said:

Out of interest, what is the actual outcome everyone is worried about? Ofcourse all cars need due diligence and have common failure points, what is the big concern of a battery SoH vs any other high ticket failure gearbox/turbos etc.

I'm not trying to troll just working out what the problem really is, it'll hit 0% in a few years and not even start the engine? It will no longer have enough to juice to boost road driving / track driving? Or just it wont have much electric only range?

SF90s are coming up to 5/6 years now are we seeing replacements under the Ferrari hybrid warranty happening / are needed by many cars? BEVs obviously hold up very well in reality, PHEVs do seem worse but even the worst examples seem to basically flatline around 70% - do we not expect Ferrari to match that? Or is that already bad enough?

They seem like such a bargain regardless to me!

Thanks for your comment. In an earlier post I go through the likely driving implications of a degrading HV battery (HVB).

If a car is under Ferrari hybrid warranty / the hybrid extension programmes, then in general there’s not much to worry about in day-to-day terms — it’s mainly an ownership/risk question once you’re out of cover. There are already cars being advertised (at Ferrari dealers) with HVB SoH readings in the 60s, so the key question is really: what happens if it keeps degrading?

A few points to separate out:

It won’t “hit 0% and not start the engine.” The ICE can still run even if EV mode and e-boost are limited. The usual symptoms of a tired pack are less EV range, and potentially more conservative e-boost / reduced repeatability under sustained high load (track, repeated hard pulls), rather than the car becoming undriveable.

SoH isn’t a single “fail point.” In most cases you’ll see gradual changes (range/boost/time in e-modes), unless you get an actual fault (cell imbalance, isolation fault, etc.) which would trigger warnings and restrictions.

Out of warranty is where it bites. If you’re out of cover and you need to replace a 296 HVB, you’re looking at roughly £35k (order of magnitude) which obviously changes the “bargain” maths completely.

So for anyone shopping these, the practical questions are:

is the hybrid warranty active and continuous, and

what does Ferrari actually do in practice at different SoH levels / symptoms.

If anyone has real-world SF90/296 examples (mileage/usage/SoH and what Ferrari did), that’d be really useful data for this thread.

The one issue that could occur whilst your car is under warranty is down time. If you start to get regular HVB error codes, etc and Ferrari determines that you need a new HVB under the warranty, no doubt that the car is going to be out of action for a while.

[LondonCarGuy]

Chrisatronic said:

OK so it's more of a 'computer says no' concern.
If some certain (unknowable) combination of degradation / cell balancing / heat / other occurs to the point where the car ecu basically says no, you're in limp mode until the battery is repaired/replaced.

I guess everyone is in wait and see territory, hence the current depreciation / market timidness. Hopefully by the time this actually starts hitting cars (if not yet, when? 8, 10, 15 years?) a good indie solution will exist.

Interesting! Seems like right now the 'sweet spot' might actually be a newer car with some manufacturer warranty left, get to year 5 then get out. Or if you think the battery risk is overblown a later car could prove a real bargain, maybe keep an eye on SF90s as a guide.

Agreed. To me, the SoH is not something to be scared of, it's just another thing to check like the car's mileage. Some people like buying a 2k mile car instead of a 12k mile car. The 12k mile car is likely much closer to needing new brake pads, new tyres, etc. It's not like the 12k mile car is a bad car, it's just likely closer to needing some work.

A 70% SoH HVB car is probably closer to the point of getting errors and needing a new battery than a 95%. But that doesn't mean the 70% is "bad".

[LondonCarGuy]

James, thank you for making the video on Ferrari hybrid warranties:

https://youtu.be/A5iOPLQ2ALY?si=II863P0znMJrCz28