Mild Hybrid 48 Volt Vehicles

[@drewpowers6038]

AWESOME video. I recently bought a 2024 BMW mild hybrid. Had no idea how it worked. You thoroughly explained the mechanics & benefits! Thank you!

[@simonreeves2017]

Hi Jason, thanks for this video on mild hybrid technology. I’m 58 and have done the majority of my own car maintenance since the 1980’s, as you will know, car electronics has evolved hugely since then. My first car was a 1974 Renault 12TS, the TS got a rev counter and a coolant temperature gauge 😂. This car had an old school electrical system with no electronics, an alternator with mechanical voltage regulator, a distributor with points and condenser driving a coil. The fuel system was entirely mechanical ending in a carburettor. This design was simple and generally reliable, though points and condensers needed regular adjustment. 48V systems would have made sense even with this technology, cold cranking these old cars put a huge strain on the 12V battery, and coils had a ‘starting mode’ to boost the output HV when the starter motor was engaged. Cars have come a long way, mainly due to their electronics and better metalagery allowing less ware of the internals. I think this process reached its optimum in the 1990’s, but has now gone too far creating too much complexity. Nearly all the problems I help friends and family with now are related to anti-pollution systems such as EGR. I also advise people to disable their Stop/Start feature 90% of engine ware occurs at startup, so this technology goes against the long term heath of a combustion engine. Having said all this, I actually think the future of personal cars belongs to the pure battery vehicle. Traction battery technology will continue to get better and an AC motor makes for a very reliable, low maintenance and efficient propulsion system. It’s very hard to fight the laws of physics.

[@raxxmoriti]

your comments are well thought out and logical. I also think that battery electric cars are the future. The laws of physics reing supreme

[@SislikCZ]

Really nice video, thank you! Just small hint for your next video volt symbol is capital V and watt is capital W.

[@verdeboyo]

Hey Jason, thank you so much for this very detailed info. Ive just purchased a Volvo XC40 Mild hybrid and wondered about the system and fascinated in how it actually does work and altho not a fan of the 'stop start' I had on my Audi S3, I had a feling the new car would have it. I'm embracing the stop start with the Volvo now after watching this So does this also mean the 12v battery up front is also Lithium Ion due to being smaller now?

[@MrSensible2]

Nice to watch a KZbin video on hybrids that's not loaded up with extremist & alarmist nonsense. Just out of curiosity, as batteries get better, lighter & cheaper, might we see further developments in mild hybrid tech, say a move to 60V or higher? If a mild hybrid could do just a couple of miles on electrical power alone, this might make a lot of sense to a lot of people who consider themselves 'green' but see EVs & PHEVs as costly & very compromised technologies.

[@ChrisCryptoCoffee]

What you are describing is exactly what a full hybrid is. It's small enough to not weight down the car significantly but it it's enough to start and run the car in EV mode one mile or similar. By inteligent calibration and regen braking, you can actually drive at least 50% in EV mode in a city. Mild hybrid is just a gimmick. Full-hybrid is the real deal

[@MrSensible2]

@@ChrisCryptoCoffee TBH, I'd forgotten I wrote that three years ago! As regards what you say, I'm not convinced it's correct. The new MG3 is a full hybrid but in terms of real-life fuel economy, it's not that different from the new Suzuki Swift 1.2 litre 12V mild hybrid. The problem with full hybrids is that all that clever tech adds a significant chunk of weight to the car, about 350 kgs in the above comparison, that negates a lot of the advantage.

[@ChrisCryptoCoffee]

@@MrSensible2 MG3 is a first generation hybrid and awful with fuel economy. Have you looked at Toyota Yaris? There are people who can get under 3l/100km in the city with it. And with Corolla getting 3.5l/100km is easy

[@MrSensible2]

@@ChrisCryptoCoffee True but the Yaris is cramped, the interior is decidedly low rent & it's very expensive for what it is. I regularly get 4.0 I/100 km from my existing non hybrid petrol car which cost me £7k & it's done this consistently for the last 8 years. Fuel consumption is extremely important to me but it's not the only consideration.

[@ChrisCryptoCoffee]

@@MrSensible2 you are cherry picking facts. You took the MG3 for the fuel economy (which is the worst) and Yaris for interior space (yes, it's the smallest). You know why Yaris costs what it costs? It's very reliable, very economical, easy to drive and quite sporty. You just ignored Corolla. And I highly doubt that your standard petrol car gets your 4l in the city

[@ah8425]

The 48v Alternator in my Audi went duff after 40k miles on a well maintained car. Seems alot of Audi owners have gone through the same thing.

[@techtonicsystems]

Interesting, thanks. So hard to find specifics around my B5

[@trevormccomb1]

Interesting surname. I wonder if we have common ancestry. I came looking for MHEV and found this. Thank you.

[@bertrammichie]

HI Jason, i take it that there would be 48 volt at the starter/generator when the engine is not running. and it would use the 12 volt battery to crank the engine over with the normal starter motor? and when engine is running you would move off and when we get to a stop the engine would shut down and when we need to move on the starter generator would start the engine to move on. is this right? thanks Bert

[@ProfessorOzone]

If the 48V system has a DC-DC converter to bring the voltage down to 12V, why do you need a 12V battery at all? If the MHSG can start the car after you come to a stop at a traffic light, why can't it start the car initially?

[@canyoncruzr3462]

Good point! ?

[@ronair5]

Ive got a 2022 hyundai i20 with this system , I have to charge the 12 volt battery every 3 days or the stop/start and the mode they call sailing stops working , within 3 months from new the 12 volt battery went flat so i couldnt start the engine AA came out to it and charged the battery . had into the dealer they done a software upgrade but its still the same , I have to charge the battery overnight for the stop/start and sailing mode to work , after 2 days its back to not working , i have found out that if the 12 volt battery drops below 80% these things stop working. I dont think the hyundai dealer hasn't a clue whats wrong with it but they wont admit it, never buy one of these again.

[@GbMuthu]

Hi, very informative video. Since the FMO mode handles stalling speeds and the ICE shutdown, can a CVT be paired directly to the ICE avoiding the torque converter from the drivetrain?

[@marcuswong4685]

Well explained, thank you

[@jjdiddle7150]

Great job.

[@derekwhitacre9165]

I have a jeep with a 2.0 e tourqe engine. I deliver mail so I stop/start about every 50 feet all day long. All is uphill or down hill. Should I turn off the auto start stop?

[@Zeeturbo]

Really informative.

[@felixsharley3728]

does it make ur car faster?

[@MrSilviugordes]

Hello Jason. Any recomandations for on the shelf components ? I am looking have my turbo diesel car to a mild hybrid.

[@cq44b]

Hi Jason, are you aware of the massive problems with the Kia/Hyundais 1.6crdi mhev48v. The tensioner from the starter generator fails and in some cases the engine seizes. As of September 2022 several hundred of these vehicles are at dealerships awaiting either new engines, rebuilds or new tensioner. I’ve bought one some 6 weeks ago unaware of the ticking timebomb I’m sat behind.

[@devaraju8424]

What is FMO mode

[@GbMuthu]

The ICE is shut down and the vehicle is driven by the ISG.

[@Sumerdini]

Batteries are very very expensive & not cost-effective for ordinary users. A mild hybrid battery costs 3000$... The life-span of a mild hybrid battery is 5 to 8 years only...

[@old8088]

From Which sourcrs you found those informstions?

[@billhickswasgreat3421]

I'm sorry, but this is stupid. They should have been able to throw out the 12V starter. This is just lazy engineering! Anyway, thank you for the nice presentation, I've been looking for proper information on these 48V systems.

[@ChrisCryptoCoffee]

The 12V battery is responsible for powering the vehicle's auxiliary electrical systems when the car is off. This includes lights, dashboard displays, infotainment systems, power windows, door locks, and other electronic accessories. Many of these systems are designed to run on 12V and can't directly use the high-voltage traction battery. Using a high-voltage system to power basic electronics could be unsafe and inefficient. The high-voltage battery in hybrid systems often operates at voltages ranging from 200-600 volts. The 12V battery keeps things safer for minor electronic circuits and simplifies the vehicle's electrical architecture by segregating the low-power components from the high-voltage ones.

[@ProfessorOzone]

If the 48V system has a DC-DC converter to bring the voltage down to 12V, why do you need a 12V battery at all? If the MHSG can start the car after you come to a stop at a traffic light, why can't it start the car initially?

[@rel6294]

12V is the auxiliary battery, for powering accesories (lights, aircon, audio etc). 48V battery is purely for the ISG. even BEV with large main battery still have separate 12V battery. even Tesla still use 12V aux battery

[@rel6294]

48V battery barely have enough capacity for ISG, let alone integrating whole car electronics into it. and ISG can do the initial start of the car, thats why when you start-up MHEV car they dont have starter motor sound, because its done by ISG

[@ProfessorOzone]

@@rel6294 Yeah, still doesn't make sense to me. The 48V battery has a lower density than the 12V battery?

[@rel6294]

@@ProfessorOzone i would say its not about the density, the purpose of having 2 separate battery is a way to stabilize the electric supply to the car

[@rel6294]

@@ProfessorOzone modern electronics in car like ECU, sensors are very sensitive to current and voltage change. 12V battery ensure these sensitive electronics to receive a stable and constant flow of electrics