Tag Archives: 48V

Volvo 2022 ‘XC60’ ‘Mild-Hybrid’ Loses Horsepower To The Electric Motor Rather Than Gaining Any?

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by Anura Guruge
on July 30, 2021

I got an update to this directly from Volvo. Though you will find this, as yet, on the Volvo Website, I was told, with some evidentiary printed documentation, that the ‘mild-hybrid’ electric motor, i.e., the ISG (below), delivers 13hp when acting as a motor. So, the electric motor can add 13hp to the overall HP giving the 2022 XC60 B5 a total of 260hp. OK? So, 10hp more than the ‘old’ T5 — albeit this HP only kicking in when you want acceleration, typically from a standstill.

Click to ENLARGE.
Click to ENLARGE. This ISG is BOTH a generator cum motor. Dual role. Most of the time a generator, occasionally when more power is needed a small, auxiliary motor.

The above picture of the ‘ISG‘ (which I also used in yesterday’s post) kinds of tells you why this is — if you think about it.

In a ‘Mild-Hybrid‘ you don’t have a big enough motor (or for that matter battery) to drive one set of wheels (let alone two). You have a small motor that kicks in, intermittently, to add a little bit of extra power. The rest of the time, as I explained yesterday, the ISG acts as the car’s alternator. But, it is a BIGGER more power-hungry alternator than what you would get in a non ‘mild-hybrid’. Hence, the drop in HP. Notice that the torque is not changed — since that is what is produced by the internal combustion engine.

From what I have read, mainly from Europe, in the case of the Volvo XC60 the extra mpg of the mild-hybrid, at best, is 3 mpg! Yes, an additional 3 miles per gallon. In my 2021 Volvo XC60, without trying, I am getting 29mpg, per the car’s computer. I am pretty sure I am unlikely to get much more with the XC60 mild-hybrid. So?

This is ONLY a solution that Swedes could have come up with. It is worse than a ‘No-OP’. It is, from what I can see, a ‘Negative-OP’. I am hoping that Volvo proves me wrong. Appears they have. The ISG is supposed to provide an additional 13hp when it kicks in, as a motor, when the vehicle is trying to accelerate.

Many Of Volvo’s 2022 SUVs Will Be HYBRIDS, At A Minimum, ‘Mild-Hybrid’.

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by Anura Guruge
on July 29, 2021

Click to ENLARGE. This ISG is BOTH a generator cum motor. Dual role. Most of the time a generator, occasionally when more power is needed a small, auxiliary motor.
Click to ENLARGE.
Got this from the ‘Volvocars.com‘ Website.

This, from what I understand, applies to many of the Volvo 2022 SUVs, at least to the XC60 & XC90. There are also electric & hybrid versions of the XC40. All the petrol (i.e., gas) engines, at a minimum, will have these SMALL, dual-role electric engines called ISGs. See caption on top.

As anyone who knows electricity will tell you, an electric motor can act as a generator & vice versa, i.e., a generator can act as an electric motor. Different modalities, i.e., it has to be one or the other at any given time, but the roles are interchangable. Depends whether you are giving it power from a battery in which case it acts as a motor, or whether you are spinning it with external power, in which case it generates electric power. Volvo is cleverly exploiting this — albeit with some very fancy & intricate electronics.

ISG acts as the cars starter & generator when it has to using the main 12V battery.

There is another 48V battery that gets charged each time you hit the brakes. This electrical energy stored in this battery is used to drive the ISG when the SUV needs extra power — e.g., when starting up or accelerating. So, the ISG only acts as a motor for very short bursts of time, seconds at that (if not shorter). Rest of the time it is the car’s alternator. The 48V battery sits there getting charged when you hit the brakes. In this type of system the ENGINES is first used to slow down the SUV (while charging the battery) before the brake pads are engaged. Very clever, BUT loads more of things that can go wrong! The electronics are so intricate ….

The ISG is NOT strong enough, by itself, to drive either the front or back wheels. So, this is NOT like a proper hybrid. With Volvo’s Mild-Hybrid the internal combustion engine drives ALL the wheels that need to be driven, depending on whether it is FWD or AWD. When I first ran into Mild-Hybrid, I was spooked that I would have to rely on the ISG for my AWD. Not so. Huge relief.

Click to ENLARGE. From Volvo.