Hi Paul
I am assuming you have not flattened the battery yet?
If this is the case you are getting a false indication of battery SOC, which I will explain.
At -5c I would experience a loss of about 1/2 a kw of capacity compared to temperatures above +10c.

2 things are happening.
Firstly
After a couple of weeks of use the BMS is instructed to decrease the operating window of the pack this would usually coinside with dissapearence of messages from the display such as “restricted motor braking” when the pack is full, as there is now plenty of head room to dump the regen.

Secondly
The SOC meter is not giving you a proper reading of capacity which links through to the range estimate software.
I have had to get this sorted. (3 weeks ago) The garage conducts black magic when you are not there and performs a complete discharge and charge cycle.
You are then instructed to perform 3 further complete discharge and recharge cycles yourself.
This involves completly flattening the battery to the point where the car shuts down completly whith messages on the screen to that effect.

At this point the SOC meter will read true to the 1/2 mark.
So if you drive of with a fully charged pack and the KW odometer zero’d you will get a representitive reading which will be doubled when the gauge hits 1/2
So if you find 10kw consumed at 1/2 your actual allowed capacity is 20kw.

Below the 1/2 mark you will notice the gauge falling much quicker, this is because (I estimate) the bottom half is actualy 1/3.
When you hit bottom and go through to restricted performance there is still at least another 2kw available.

I would not suggest you do this without discussing the issue with your garage first.
My Fluence was giving an estimate of capacity bellow 16kw but I new it had to be considerably more from the charging data I had.
The 1/2 mark on the SOC gauge is accurate within what the system estimates to be the operating window of the pack, so if the pack is not regularly being flattened(I would never) it is not accuratly estimating the capacity.

I am assuming the bottom half of the gauge is skewed to frighten the user into not going to low.
There is another issue with cold weather which I keep meaning to ask to be rectified.
I would normally drive with the climate control shut of, but the software will heat up the system when you open the door (you would have heard a funny expanding sound as you get into the car)and keeps it warm so there is still consumption to keep that system warm under the bonnet.
I know there has been an update on the old leaf to prevent this.
If you now of any body who has persued this?

Sure, a 20% variation – 10% for heating and 10% because the density of air at 0C is 10% higher than that at 25C.

EVs are so efficient that there is very little left to notice relatively (proportionately) big changes. There are so many losses in an ICE that you would be hard-pressed to notice air density. In fact, it is mitigated to an extent for ICE because the engine runs more efficiently with the higher density air.

For an EV merrily bowling along the road at 50, the vast majority of the energy required is from aero-drag. You may need a bit more power going up hills but what you need up is mitigated by coming down again. So that leaves air. Increase density 10% increases aero-power 10%. Simples.

Your battery sounds fine. OK, it is possible that the percentage of battery made available to you (you never get to use all of the battery) may be regulated by software monitoring the ambient, and it may well reduce the accessible SOC at lower temps a little bit. But I doubt by much, as I think the Fluence has a bigger battery capacity than other EVs of nominally similar capacity and I think it should be able to easily accommodate the mild UK temp range.

No obvious reasons to panic yet, Paul! It’ll be back to 100+ in summer, I am confident.

Hi Guys … my first tentative step over from renaultzeforum …

Paul, as mentioned over there, I think you will find that the kWh and the MPkWh gauges on the Fluence do not indicate the energy used in heating (or AC).

Only the immediate kW gauge includes an indication of current HVAC (plus traction) power drawn.

In other words, if your kWh gauge is, proportionately, indicating 15 kWh battery capacity, then the ‘missing’ 7 kWh is what you’d be using for heating. i.e. a third of all the energy you’re currently using is heating alone.

That’s really not that bad, if your using the inefficient ‘eco’ heating mode, or your heating settings are pointed into the whole of the car. You can’t really expect any more from an EV – an ICE rejects more energy into the heating system than it uses for traction, so if you want that much heating then you should anticipate doubling your energy use per mile.

An EV is very efficient turning the energy it has got into tractive power because it does not reject waste heat from the drive train. However, that is not altogether ‘waste heat’ when it gets cold!!

I recommend you set the ventilation manually to footwell-only and set the lowest fan speed, and you will then only use 10~20% of your energy for heating. I’m confident you’ll find the resultant cabin conditions will be ‘tolerable’ bordering ‘pleasant’ (but definitely not ‘toasty’) and your battery capacity calculations will look ‘more normal’ then.

i’ve noticed a slight dip in mileage but not more than about 6 miles.

i also found resetting the eco trip meter usually gives you some mileage back.

the charge cycle does seem to take longer tho. normally a completely flat battery was saying 3.45 but now it still says the same when its cold but it has on one occasion taken taken over 5 hours…

Great piece of analysis, Trevor. It’s frustrating that low mileage users pay more, because that’s the category we fit into (sub 30 miles per day). Also, I don’t have economy 7, so pay more for electricity.

The petrol car we traded in did not get such great mpg as you’ve quoted in your table for a new Clio, so that weighs a bit more in our favour.

It seems Renault are over-charging for battery rental on lower mileages. That said, is it a coincidence that petrol prices are coming down just at a time when electric vehicle sales are taking off? <Put your own conspiracy theory in here>

It would seem that charging away from home could turn out to be much cheaper, assuming those costs are recorded as membership (£10 per year for Chargemaster, free for Ecotricity) rather than KWh consumed.

Overall it means we’ve bought on principle rather than because it makes financial sense. I mentioned all this to the wife, who’s only response was that she prefers the ZOE because she doesn’t have to go out of her way to get petrol any more, which is important to her and shows that sometimes consumer needs outweigh £ per month!

Cheers,
Mark

Trevor, thanks for setting up this forum to provide a home for those of us suffering elsewhere. I hope shortly to meet up again with all my Fluence ZE friends. I must say, travelling from the old site to here was quite swift and seems to have used very little battery! Hope I can modify my password, need a degree in gobbledygook to remember that…..