Battery Charging while driving - engine whining

[sifranci]

When our PHEV is low on battery charge and we are driving, the engine kicks in to power the battery (normal operation) however we have noticed that in this instance the engine seems to be running in a high gear and makes a noise similar to running a standard car in the wrong gear. The garage has told us this is normal but I can't see that this is correct. Has anyone else noticed this or have a fix/explanation.
Thanks

 

[Daff]

In series hybrid mode, engine revs don't have a straightforward relationship to the road speed like they do in a conventional car. It will rev higher than you expect at times. It's a quirk of the design.

Steve

 

[anko]

In series hybrid mode, engine revs don't have a straightforward relationship to the road speed like they do in a conventional car. It will rev higher than you expect at times.

And don't forget, the engine drives the car AND charges the battery at the same time. So, power output demand will be higher than in a conventional car at the same speed. To meet this demand, higher revs are needed.

 

[jaapv]

When our PHEV is low on battery charge and we are driving, the engine kicks in to power the battery (normal operation) however we have noticed that in this instance the engine seems to be running in a high gear and makes a noise similar to running a standard car in the wrong gear. The garage has told us this is normal but I can't see that this is correct. Has anyone else noticed this or have a fix/explanation.
Thanks

A "normal" car will have its engine revolutions dictated by roadspeed (obviously related to the gear it is in) We all have become used to this behaviour.
However, a car with a series hybrid ICE or a CVT will adjust the engine revolutions to the engine load, which sounds very strange to us - initially. It is simply a matter of adapting our expectations to a different concept.

 

[maby]

The high revving annoys me seriously. I drive on "Save" mode most of the time to keep the charge level high and that does significantly reduce the whining. But you have to understand that most of my usage is long distances with no opportunity to charge up the battery, so it is primarily a petrol driven car for me and keeping the charge level high has little impact on operating economy.

 

[sifranci]

Thanks all for the responses. So in effect working as designed but also agree with Maby it's an annoying sound and passengers always comment. Will continue to turn the radio up to drown it out, maybe that is the fix.

 

[maby]

Thanks all for the responses. So in effect working as designed but also agree with Maby it's an annoying sound and passengers always comment. Will continue to turn the radio up to drown it out, maybe that is the fix.

I don't think there is a single answer to this problem - it is dependent on usage of the car. If, like me, your typical usage is a journey of around 200 miles without ability to charge, then the 20-odd miles of EV range make little difference to the overall operating costs (or, for that matter, environmental impact), so you may as well press the "Save" button soon after starting, keep the battery close to full, and avoid a lot of banshee wail. Really, it only becomes an issue when your journey is a bit longer than the likely EV range - then you have a decision to make - are you going to manage the battery for optimal fuel consumption or not? If you do, then that may leave you climbing a steep hill near the end of the trip with a flat battery and the engine screaming its guts out!