HV Battery State of Health (SoH) - what to ask before buying
Discussion
XMA Simon said:
Also the failure rate for Li-Ion batteries (in general - not just for cars) is something like 1 in a million. While that sounds good that is one in a million cells and some of these auto batteries have hundreds to thousands of cells. And if they short circuit with significant charge stored they catch fire and it is BBQ time.
So besides the debate around performance all this battery management software is there to minimise the risk of a fire event. So when the software says to switch the battery it becomes a real safety priority to get it done.
Ferrari, Porsche and all the other car companies need to improve communication and transparency particularly in these performance hybrids where rapid, frequent charge / discharge cycles are placing heavy loads on HV batteries.
I suppose now we can see why the 296 Challenge car does without the HV / hybrid gubbins. Imagine a road version of that... it would sell like hotcakes!
It used to be quite simple to evaluate a car. Now you need degrees in chemistry, engineering and IT / software to evaluate them. LOLs.
I'm nowhere near affording a 296 yet so it's not an issue for me but like you say the manufacturers need to sort this out otherwise the depreciation on these £200k plus cars will be horrendous and put buyers off.So besides the debate around performance all this battery management software is there to minimise the risk of a fire event. So when the software says to switch the battery it becomes a real safety priority to get it done.
Ferrari, Porsche and all the other car companies need to improve communication and transparency particularly in these performance hybrids where rapid, frequent charge / discharge cycles are placing heavy loads on HV batteries.
I suppose now we can see why the 296 Challenge car does without the HV / hybrid gubbins. Imagine a road version of that... it would sell like hotcakes!
It used to be quite simple to evaluate a car. Now you need degrees in chemistry, engineering and IT / software to evaluate them. LOLs.
Edited by XMA Simon on Friday 9th January 19:15
I was thinking about the challenge not being a hybrid and then saw your post about it. Could we ever get to a point where instead of paying £30k to replace a failing battery an independent could remove it and you run it as a ICE car or would it be too complicated? It would still have 654hp which is more than enough for most people.
By the way, my comment re the Revuelto is most likely irrelevant based on some reading. Ferrari and Lambo have taken two different approaches. Lambo uses the battery to deliver a fast torque fill punch and it also charges very quickly. It’s more like a capacitor. The 296 is like a traditional PHEV that requires the battery to feed the electric motor to hit peak power and it’s not recharging as quickly. So a degraded battery in a 296 doesn’t provide the same charge buffer required over a lap let’s say. I would have thought with the 296 you will always hit a power limit if you’re on max attack for long enough, it’s just a question of when. It looks like Ferrari has prioritised CO2 rating and EV range in addition to power. And given that Ferrari is offering a battery replacement programme, it seems they also agree that the battery needs to be in tip top shape for the car to operate as intended.
Or something like that lol.
Or something like that lol.
Thank you for all the info, I am actively in the process of viewing a GTS next week, told the sales guy i would like to know the SOH and his reply was 'first time he's been asked this'
It does put me off buying anything Hybrid, i usually whack the car on a trickle charger as soon as i put in garage, now my head is all over the place as to what to do and not to do
It does put me off buying anything Hybrid, i usually whack the car on a trickle charger as soon as i put in garage, now my head is all over the place as to what to do and not to do
MeisterH said:
Thank you for all the info, I am actively in the process of viewing a GTS next week, told the sales guy i would like to know the SOH and his reply was 'first time he's been asked this'
It does put me off buying anything Hybrid, i usually whack the car on a trickle charger as soon as i put in garage, now my head is all over the place as to what to do and not to do
After you buy your car, this is directly from Ferrari Hybrid Charging materials, "When parking for longer than two weeks, please enable Long Parking Mode. The system automatically manages battery levels to maintain the ideal charge and prevent premature battery aging."It does put me off buying anything Hybrid, i usually whack the car on a trickle charger as soon as i put in garage, now my head is all over the place as to what to do and not to do
Frankly, if you are going to store the car for a week, I would use Long Parking Mode. As Ferrari says, "prevent premature battery aging".
I’ve been digging into how the HV battery’s state of health actually shows up in the way the 296 behaves, and thought it might be useful to lay out the mechanics behind it.
Baseline Numbers
• The e‑motor contributes roughly 167 hp (123 kW)
• The HV battery is about 7.45 kWh gross, with ~6.5 kWh available once Ferrari’s buffer is accounted for
• If you ran the motor flat‑out from the battery alone, you’d drain it in around three minutes — although the hybrid control system never allows anything close to that in the real world
How the “3‑Minute” Figure Comes About
Take the usable battery capacity and divide it by the motor’s peak draw and you get the theoretical maximum duration. That’s the lab‑math version. Out on the road or track, thermal management and software limits mean you only ever see short, intense bursts — typically 30–60 seconds of full shove before the system starts managing itself.
Track Behaviour
This is where SoH becomes most noticeable because the battery is repeatedly asked for maximum current.
• Around 90% SoH: Hybrid boost is stable through a 20–30 minute session. Torque fill feels identical lap after lap.
• Around 70% SoH: You still get full‑power bursts, but fewer of them. After 5–10 minutes of pushing, the car may start rationing electric assist until regen catches up. The driving experience shifts toward “V6 with hybrid help” rather than the seamless blend you get when the battery is fresher.
• Heat sensitivity: As SoH drops, the pack heats up more quickly, which shortens the window of maximum hybrid contribution.
Fast Road Use
Degradation is much harder to detect on the road because you rarely stress the system continuously.
• 90% SoH: Feels essentially new. Every acceleration has the same hit of torque fill.
• 70% SoH: Peak power is still there, but if you chain several hard pulls together you’ll notice the system backing off sooner. Electric‑only range shrinks, though that’s largely academic in hybrid mode.
Baseline Numbers
• The e‑motor contributes roughly 167 hp (123 kW)
• The HV battery is about 7.45 kWh gross, with ~6.5 kWh available once Ferrari’s buffer is accounted for
• If you ran the motor flat‑out from the battery alone, you’d drain it in around three minutes — although the hybrid control system never allows anything close to that in the real world
How the “3‑Minute” Figure Comes About
Take the usable battery capacity and divide it by the motor’s peak draw and you get the theoretical maximum duration. That’s the lab‑math version. Out on the road or track, thermal management and software limits mean you only ever see short, intense bursts — typically 30–60 seconds of full shove before the system starts managing itself.
Track Behaviour
This is where SoH becomes most noticeable because the battery is repeatedly asked for maximum current.
• Around 90% SoH: Hybrid boost is stable through a 20–30 minute session. Torque fill feels identical lap after lap.
• Around 70% SoH: You still get full‑power bursts, but fewer of them. After 5–10 minutes of pushing, the car may start rationing electric assist until regen catches up. The driving experience shifts toward “V6 with hybrid help” rather than the seamless blend you get when the battery is fresher.
• Heat sensitivity: As SoH drops, the pack heats up more quickly, which shortens the window of maximum hybrid contribution.
Fast Road Use
Degradation is much harder to detect on the road because you rarely stress the system continuously.
• 90% SoH: Feels essentially new. Every acceleration has the same hit of torque fill.
• 70% SoH: Peak power is still there, but if you chain several hard pulls together you’ll notice the system backing off sooner. Electric‑only range shrinks, though that’s largely academic in hybrid mode.
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 !
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 !
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 !
What are they saying about this and why is it taking so long?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 !
When I had to reject my 296GTS last year, Although the main dealer was extremely difficult I managed a resolve and monies returned within 7 days. This was within 30 days of Purchase so slightly easier.
Trollbuster said:
What are they saying about this and why is it taking so long?
When I had to reject my 296GTS last year, Although the main dealer was extremely difficult I managed a resolve and monies returned within 7 days. This was within 30 days of Purchase so slightly easier.
I’m having to go through Ferrari finance (owned by Ferrari) and they won’t reject it, so now using the financial ombudsman.When I had to reject my 296GTS last year, Although the main dealer was extremely difficult I managed a resolve and monies returned within 7 days. This was within 30 days of Purchase so slightly easier.
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. 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'm really sorry you guys had to get the cars rejected.
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