Drivetrain

[pkulak]

I just have a couple questions, if anyone has a moment to indulge me!

It's my understanding that the Outlander PHEV doesn't actually have a "geared" transmission. It runs as a series hybrid only under a certain speed, and then on the freeway, the engine can be clutched in to the front wheels to avoid the series hybrid losses. I think the new Accord hybrid does this as well. It's ingenious: super simple (no planetary gear sets or multi-speed transmissions) and also very efficient.

My question then (assuming I'm right) is, how much energy can the battery supply to the motors? It's only 12 kWh, so I'm guessing maybe about 60 kW max? Since the motors are 120 kw, under hard acceleration, the motor needs to spin up the generator to provide the rest of the power? How much do you need to accelerate before the engine turns on? Do you really need to have a lead foot, or does it pop on and off a lot during normal driving?

Thanks for any help! It's proved pretty tough to get any technical information about this car. Hopefully they can get it stateside soon: I'm getting sick of waiting!

 

[maby]

The Outlander effectively has a single speed gearbox with a ratio equivalent to 5th on most conventional cars - it can engage at something above 40mph and will carry it through to its top speed around 120mph (ish).

The electric drive train is able to take the car up to around 70mph provided there is sufficient charge in the battery. At speeds below about 40mph, the drive is always electric - if there is sufficient power in the battery, it will run on battery alone in warm weather, at least. If the battery is allowed to discharge, then the petrol engine starts and drives the generator which, in turn drives the electric motors. The control systems run the engine at more or less its optimum speed for efficiency and any spare output from the generator is dumped into the discharged battery.

In warm weather, the car will try to run off the battery for as long as possible. If you demand more power than can be supplied from the battery alone, then the petrol engine kicks in and either drives the generator or drives the front wheels directly if your speed is high enough. While you have charge in the battery, this will only happen on steep hills or under high acceleration.

The behaviour changes quite significantly when the temperature gets close to freezing. The engine starts much sooner - partly to provide heating to the car and partly because battery performance drops off as the temperature drops. In the summer, I was able to get close to 30 miles out of the car on pure EV - now, less than six months later, I reckon I'm doing well to get 16 miles.

 

[pkulak]

this will only happen on steep hills or under high acceleration.

How much acceleration does it take? How much power can the battery provide before the engine needs to spin up?

 

[jaapv]

60 KW. On paper.

 

[pkulak]

60 KW. On paper.

Ah, that makes sense. Half the total power comes from the battery, the other half from the engine generator, if you need it.

How smooth is the transition if you floor it?

 

[jaapv]

You only hear the engine revving. It sounds like kickdown on a regular CVT.

 

[anko]

if there is sufficient power in the battery, it will run on battery alone in warm weather, at least.

At -2 deg C it still does. As long as you do not use the heater or make sure the car is sufficiently pre-heated (models with electric heater).

The control systems run the engine at more or less its optimum speed for efficiency and any spare output from the generator is dumped into the discharged battery.

You wish ;-) This picture (actual Mitsu pic for the PHEV) shows how much torque is needed for driving (green line) and where the soft spot of the engine is (blue oval):

The large white text in the middle of the pic says: available spare torque, used for charging the HV battery. But, when you park your car and charge it by means of the ICE, the engine outputs 90 Nm @ 1100 rpm = 10,4 kW. The battery is charged with 27 Amps. At 300 volt that would be 8,1 kW. The rest would be losses in the generator and he convertor. You may assume that charging while driving consumes about the same 10,4 kW. At 100 km/h (2630 rpm) it would take about 37.6 Nm to produce that amount of power. Add this to the 75 Nm needed for driving 100 km/h, you get a total of approx. 112 Nm, about 30 Nm short of the sweetspot. At lower speeds the gap between actual output and optimal output is even bigger. Between 80 and 90 km/h you would need to charge the battery at ChaDeMo fast charger speed in order to get near the sweetspot. Not a good idea, as a standard mode.

In warm weather, the car will try to run off the battery for as long as possible. If you demand more power than can be supplied from the battery alone, then the petrol engine kicks in and either drives the generator or drives the front wheels directly if your speed is high enough. While you have charge in the battery, this will only happen on steep hills or under high acceleration.

Again, I don't think temperature (modest freezing) has an impact, although the engine might be running for heating purposes. But if you are taking off from a traffic light (summer or winter) and try to keep up with traffic in the fast lane, the engine will most likely kick in.

The behaviour changes quite significantly when the temperature gets close to freezing. The engine starts much sooner - partly to provide heating to the car and partly because battery performance drops off as the temperature drops. In the summer, I was able to get close to 30 miles out of the car on pure EV - now, less than six months later, I reckon I'm doing well to get 16 miles.

Usable capacity of the battery deteriorates in winter time, resulting in decreased stamina. That is true. But I think you can still get the power meeter to the end of the green zone without the engine kicking in. Again, unless the heater is already consuming 4.5 kW. With there heater working at max, the engine will kick in earlier.

 

[Robinham]

If you really want to know what the ICE is doing get an ODB bluetooth dongle. £8.99 on ebay. Download the free Torque App for your phone and pair them together. Set the phone to rev counter and you will see exactly what the engine is doing. It is fascinating and not exactly what the onboard display is showing, The plug point is below the dash to the right of the pedals in the UK!

 

[anko]

Set the phone to rev counter and you will see exactly what the engine is doing. It is fascinating and not exactly what the onboard display is showing

I would thing that is because the onboard display isn't showing rpm at all

There was a discussion about a "lying dashboard" just the other day. But all the dashboard tells you is wether the engine is generating energy and/or driving the front wheels. The fact that it does neither doesn't mean it is not spinning. Only when the dashboard shows serial or parallel mode while Torque shows 0 rpm, then it would be a deviation for sure. But I guess you are not seeing that.