Maintaining SOC while towing a caravan / under heavy load

[XrisTer]

Hi everybody,
I've just bought in august the MY20, and I tow a caravan of 1300kg.
For the first time, 300 km with 240 km of motorway, that was fine with the Charge mode most used.
Another user told me that he use the Sport Mode. Do you think it's more accurate?

 

[user 3575]

Like you I am new to all this we tow a 1500kg caravan, our Outlander was new in June 2020.

Follow advice on this forum, let the battery run down to 50/60% and use the charge button, over a 180 mile journey we only just maintain this amount of reserve, when I drop down below 40mph or away from junction and roundabout I switch off the charge and let the battery do its work.

At first I was achieving around 26.5 mpg, as the PHEV loosened up and gaining a little more experience achieving 27.6 mpg, 3 weeks ago towing we achieved about 28.5mpg measured brim to brim, however on the way back this Sunday we had to use the heater for 40% of the journey are overall consumption dropped back again brim to brim to 26.5mpg.

We found the Charge Mode works for use, no screaming engine in towns or junctions and tows as well as our 150bhp Ford Kuga Powershift with virtually identical fuel consumptions.

 

[ThudnBlundr]

I'm still not clear why you switch off a power supply when you are below 40mph or want to accelerate away from a junction. What are you trying to achieve by removing power produced by the ICE? I can see why you'd do it when not towing, but surely you want to maintain the battery level as much as possible when towing.

Heating should have a negligible effect on fuel consumption if the ICE is running regularly. An ICE has to disperse so much heat normally via the radiator that sending some of that waste heat to the cabin instead should not be noticeable

 

[user 3575]

I'm still not clear why you switch off a power supply when you are below 40mph or want to accelerate away from a junction. What are you trying to achieve by removing power produced by the ICE? I can see why you'd do it when not towing, but surely you want to maintain the battery level as much as possible when towing.

Heating should have a negligible effect on fuel consumption if the ICE is running regularly. An ICE has to disperse so much heat normally via the radiator that sending some of that waste heat to the cabin instead should not be noticeable

Our PHEV has an electric heater, we find the PHEV has more torque in EV mode, using this method we still manage to keep plenty of charge in reserve

 

[ThudnBlundr]

Torque comes purely from the 2 electric motors at speeds below 40mph. At very low speeds, the motors are torque-limited, so it makes no difference if the ICE is running or not. At slightly higher speeds, the maximum power draw from the battery will limit the torque available in EV. The ICE can provide additional power (and therefore torque) at these speeds via the generator, so using EV to force the ICE off reduces the torque available.

 

[user 3575]

The method I use for towing works for us, the 2020 version has a bigger more efficient 2.4 engine, a larger battery and bigger rear motor , not sure how it compare to the older 2.0 model. We can maintain about 12/14 miles whilst travelling above 40 mph, before I get to site I am usual down to 7/8 miles, by the time I get to site I am usually down to 1/2 miles

 

[ThudnBlundr]

You still haven't explained why you think that reducing the power & torque available for the electric motors makes the PHEV accelerate better. That is not a function of engine size, battery size or efficiency - simple physics makes it obvious that reduced power/torque means reduced acceleration. One slightly more powerful electric motor doesn't make up for the fact that the power supplied by the battery alone is still limited, and it needs the extra power supplied by the ICE to be able to use the full power of the motor.

 

[user 3575]

I take it you have not towed a 1500kg caravan with the 2020 model

 

[ThudnBlundr]

Please explain in simple terms how reducing the available power improves acceleration. Unless you have actual proof of how you contradict the laws of physics, your experience is wholly subjective and therefore meaningless.

 

[user 3575]

So you haven't then

 

[greendwarf]

In my experience acceleration is greater in EV mode once the ICE kicks in (overtaking, boy racing from traffic lights etc.). I can see why it should be different when towing. :ugeek:

 

[user 3575]

In my experience acceleration is greater in EV mode once the ICE kicks in (overtaking, boy racing from traffic lights etc.). I can see why it should be different when towing. :ugeek:

You have hit the nail on the head, on our 2020 2.4 model ( as I have never driven or towed with the 2.0 version, I cannot compare) if you try and accelerate from a slow speeds towing a caravan in charge mode the engine just rev's up trying to provide power to the front motor, in EV mode it provides power to both motors and as you say if I accelerate hard the ICE also kicks in producing that extra push.

The method I use works for us, we still can maintain a good 40/50% SOC reserve. To date we have only towed from the Midland to the New Forest in Hampshire and have not encountered any real hilly terrains like Cornwall.

 

[ThudnBlundr]

It is only above 40mph in Parallel mode that the ICE is connected directly to the front wheels in what is effectively 'top gear'. The engine is connected to the generator alone in Series mode below 40mph, and the car is thus only powered by the electric motors. That is why the ICE can spin at whatever revs the car decides - it is connected to nothing except the generator, so higher rpm = more electric power. In Series mode and in EV-mode, the car sends electrical power to whichever motors it sees fit. But in EV mode, the battery can supply less power to the electric motors than the ICE-generator and battery combined. At very low speeds, the electric motors are torque-limited so the ICE won't kick in, but as the car accelerates and the electric motors are able to take more torque, the ICE kicks in to provide it if you've not selected EV mode to restrict the power.

Why do you think the engine is running at high revs at slow speed when you accelerate away towing a caravan? Did it ever occur to you that it is running at high rpm to provide extra power which the battery alone cannot provide? That is why it is just plain silly to say that you can produce more acceleration with less power. The PHEV knows this to be untrue and adds the ICE to provide more power, and hence better acceleration. Or do you think it starts up just provide extra noise? :roll:

 

[user 3575]

I'm still not clear why you switch off a power supply when you are below 40mph or want to accelerate away from a junction. What are you trying to achieve by removing power produced by the ICE? I can see why you'd do it when not towing, but surely you want to maintain the battery level as much as possible when towing.

Heating should have a negligible effect on fuel consumption if the ICE is running regularly. An ICE has to disperse so much heat normally via the radiator that sending some of that waste heat to the cabin instead should not be noticeable

What really should have stated I switch the Charge Mode Off, in my case the model chooses to uses the batteries and obviously the ICE unit, but to date this happened.

The reason why I also do it whilst not towing, the engine, I just don't like the engine revving away and I always have plenty of battery reserve.

Regarding the heating when in Charge Mode towing and the Heater On, on my model is knock about 5 miles of the range

 

[ThudnBlundr]

The engine does sound a bit frantic at high load/low mph. I remember being a bit worried the first time I climbed a long, steep hill with the engine seemingly thrashing away, especially as I also got the smell of burning rubber at the top. :roll: I had to check that it was meant to do that, and found that the rubber smell was common.

Just be aware that the PHEV battery is relatively small, so high power means a high 'C' - the ratio of power (kw) to battery size (kWh). 50kW from the PHEV is around 4C (depending on model), whereas the same power from a 50kWh ZOE is 1C. Sustained high 'C' power (either draw or charge) is widely believed to cause degradation in Lithium batteries, so I try to avoid it. But that means I do have to put up with the ICE revving away instead...

 

[Fjpod]

The engine does sound a bit frantic at high load/low mph. I remember being a bit worried the first time I climbed a long, steep hill with the engine seemingly thrashing away, especially as I also got the smell of burning rubber at the top. :roll: I had to check that it was meant to do that, and found that the rubber smell was common.

Just be aware that the PHEV battery is relatively small, so high power means a high 'C' - the ratio of power (kw) to battery size (kWh). 50kW from the PHEV is around 4C (depending on model), whereas the same power from a 50kWh ZOE is 1C. Sustained high 'C' power (either draw or charge) is widely believed to cause degradation in Lithium batteries, so I try to avoid it. But that means I do have to put up with the ICE revving away instead...

So, I don't tow... but to what would you attribute the smell of rubber burning? High rate of charge/discharge of the battery? High usage of the generator/motor? I don't see how this can be normal under any circumstances.

 

[user 3575]

The engine does sound a bit frantic at high load/low mph. I remember being a bit worried the first time I climbed a long, steep hill with the engine seemingly thrashing away, especially as I also got the smell of burning rubber at the top. :roll: I had to check that it was meant to do that, and found that the rubber smell was common.

Just be aware that the PHEV battery is relatively small, so high power means a high 'C' - the ratio of power (kw) to battery size (kWh). 50kW from the PHEV is around 4C (depending on model), whereas the same power from a 50kWh ZOE is 1C. Sustained high 'C' power (either draw or charge) is widely believed to cause degradation in Lithium batteries, so I try to avoid it. But that means I do have to put up with the ICE revving away instead...

I will answer the best I can,
The PHEV was new in June, a few week later with about 300 miles on the clock we went on holiday towing our caravan, we arrived at the M6 toll road booths, as we left the booths there is steep incline like you the engine revved up and a strong smell of burning rubber, so we switched off the charge mode so basically D the PHEV switched itself to battery mode and pulled away cleanly. This has also been highlighted by the Caravan Club and all the caravan towing test the week point of the Outlander PHEV is towing away from a standing start or low speed especially on inclines, so when pulling away from very low speed or a standing start when towing I switch off the charge mode and use D mode and let the computer sort it out, I ease the accelerator so to date the ICE has not fire up as well. On the motorway in Charge mode the motor happily runs at less than 5 kWh on an steep incline on the the rear motor power up according to the display in blue, so I am assuming it is the battery.

When Not towing none off the above applies an D the PHEV is quite happy regardless in any mode.

From what I have read on the forum only use charge mode above 40mph for maximum efficiency.

In D mode with a good charge in the batteries, if I floor the accelerator, the ICE kicks in a the PHEV accelerates very quickly.

 

[zzcoopej]

to what would you attribute the smell of rubber burning? High rate of charge/discharge of the battery? High usage of the generator/motor? I don't see how this can be normal under any circumstances.

The rubber burning smell has been reported by numerous PHEV owners and has nothing specifically to do with towing as I sometimes smell it after a normal 80km trip. It is a simply due to a buildup of dirt and tyre rubber etc sitting on the muffler. A normal car burns tiny amounts away all the time so you don't notice it, however the PHEV ICE is only running occasionally and usually only runs when you are on a long trip eg freeway when it is harder to smell. So you only smell it occasionally when doing shortish 100km or so trips after a lot of EV only driving. However when towing a caravan, you smell it more often as the ICE is likely to have been running much more so muffler gets hotter etc.

 

[greendwarf]

And you're travelling more slowly (or should be :lol: )

 

[Fjpod]

to what would you attribute the smell of rubber burning? High rate of charge/discharge of the battery? High usage of the generator/motor? I don't see how this can be normal under any circumstances.

The rubber burning smell has been reported by numerous PHEV owners and has nothing specifically to do with towing as I sometimes smell it after a normal 80km trip. It is a simply due to a buildup of dirt and tyre rubber etc sitting on the muffler. A normal car burns tiny amounts away all the time so you don't notice it, however the PHEV ICE is only running occasionally and usually only runs when you are on a long trip eg freeway when it is harder to smell. So you only smell it occasionally when doing shortish 100km or so trips after a lot of EV only driving. However when towing a caravan, you smell it more often as the ICE is likely to have been running much more so muffler gets hotter etc.

Understood. Thanks.