How do you pre heat the battery

[tsedge]

To try to help you make sense of it, I think it boils down to:

1. If you want maximum range and the fastest charge speed from your car, pre-heating while plugged in will help: assuming you can do this easily (which you can't).

2. You can trade range with charge speed en-route by pre-heating. Whether this is worth it depends on the tradeoff and the journey.

 

[Rolfe]

I didn't use any pre-heating when I was driving over Christmas, and both my charging stops were reasonable - about 40 minutes to take the SR up to 85%. But it possibly wasn't THAT cold.

 

[siteguru]

IMHO, battery pre-heating (or "intelligent" heating) is pointless with the LFP pack. The charging rate is a best of about 88kW anyway, and if you're stopping to charge you're going to do other things anyway so a few minutes either way makes no difference. Ergo the battery usage from heating (unless you can do it whilst plugged into the mains) and the impact on range simply isn't worth it.

That's my 2c ?‍

 

[tsedge]

IMHO, battery pre-heating (or "intelligent" heating) is pointless with the LFP pack. The charging rate is a best of about 88kW anyway, and if you're stopping to charge you're going to do other things anyway so a few minutes either way makes no difference. Ergo the battery usage from heating (unless you can do it whilst plugged into the mains) and the impact on range simply isn't worth it.

That's my 2c ?‍

Is there any range benefit with the LFP or is it just too slow to warm up to be worth it?

 

[siteguru]

Too slow to warm up ... it doesn't self-warm whilst driving and so needs "excessive" energy from the HV battery to drive the heater. Once it is warm then it'll retain the heat for quite some time, so ongoing heating would use minimal power, but the energy needed to actually heat up makes it not worth the loss of range.

That's why @fnegroni's comment re. heating whilst plugged in then using the "intelligent" mode on a long trip makes some sense. But for day-to-day usage it simply isn't worth it.

 

[pecker]

Too slow to warm up ... it doesn't self-warm whilst driving and so needs "excessive" energy from the HV battery to drive the heater. Once it is warm then it'll retain the heat for quite some time, so ongoing heating would use minimal power, but the energy needed to actually heat up makes it not worth the loss of range.

That's why @fnegroni's comment re. heating whilst plugged in then using the "intelligent" mode on a long trip makes some sense. But for day-to-day usage it simply isn't worth it.

Am I right in that you can't turn on intelligent heating from the app ?

 

[fnegroni]

Am I right in that you can't turn on intelligent heating from the app ?

That’s correct.

 

[tsedge]

Am I right in that you can't turn on intelligent heating from the app ?

You can manually turn on pre-heating from the app, but it doesn't affect the intelligent heating setting on the car.

By the same token you can't do one shot pre-heating in the car, only toggle intelligent heating.

 

[fnegroni]

I’ll give you an example from today at about midday.
Had to drive to Asda less than 3 down the road. Very slow roads with road works.

Ambient temperature: 11C
Battery temperature: inlet 9C, lowest battery temperature 7C

Drove to Asda. No intelligent battery heating disabled. Battery temperature readings exactly the same when I arrived.

As an experiment (60 pence!) I ran the battery pre heating while waiting at the pharmacy.

20 minutes later battery pre heating had stopped, consuming 3% battery (1.5 kW)

Battery inlet temperature 35C, lowest battery temperature 17C

Drove back home.
Arrived two miles later with inlet temperature 23C, lower battery temperature 17.5

Driving in Normal mode with regen 3

Average consumption due to cabin heater being on (didn’t preheat the cabin)
2miles per kWh on way out.
2miles per kWh on way back.

The cabin heater is the range killer in winter

I could run more stats but even if you don’t pre heat the battery you still need to heat the cabin and it’s better done when connected to a charger or in advance of a short drive.

When I used to park the car in a heated garage at 17C in winter, the same journey would have given me 3.5 to 4 miles per kWh.

 

[pecker]

You can manually turn on pre-heating from the app, but it doesn't affect the intelligent heating setting on the car.

By the same token you can't do one shot pre-heating in the car, only toggle intelligent heating.

Thanks, how long does the pre heating last or what temp does it heat up to ?

I’ll give you an example from today at about midday.
Had to drive to Asda less than 3 down the road. Very slow roads with road works.

Ambient temperature: 11C
Battery temperature: inlet 9C, lowest battery temperature 7C

Drove to Asda. No intelligent battery heating disabled. Battery temperature readings exactly the same when I arrived.

As an experiment (60 pence!) I ran the battery pre heating while waiting at the pharmacy.

20 minutes later battery pre heating had stopped, consuming 3% battery (1.5 kW)

Battery inlet temperature 35C, lowest battery temperature 17C

Drove back home.
Arrived two miles later with inlet temperature 23C, lower battery temperature 17.5

Driving in Normal mode with regen 3

Average consumption due to cabin heater being on (didn’t preheat the cabin)
2miles per kWh on way out.
2miles per kWh on way back.

The cabin heater is the range killer in winter

I could run more stats but even if you don’t pre heat the battery you still need to heat the cabin and it’s better done when connected to a charger or in advance of a short drive.

Where are you getting battery temps from ?

 

[fnegroni]

Where are you getting battery temps from ?

Car scanner using OBDlink MX+

Thanks, how long does the pre heating last or what temp does it heat up to ?

Between 15 and 25 minutes. Average 20 minutes.
After which the coolant is at around 35C but the battery mass will take longer to warm up fully and equalise at around 17-20 C

and another range killer are the original tyres: when it’s cold and especially when it’s wet, they are not as efficient.
Been using Turanza 6 (proper review in a few more hundred miles) and the range is better especially when cold and wet. Compared to the premium contact C

 

[tsedge]

and another range killer are the original tyres: when it’s cold and especially when it’s wet, they are not as efficient.
Been using Turanza 6 (proper review in a few more hundred miles) and the range is better especially when cold and wet. Compared to the premium contact C

How much better is the range with different tyres? (do you have a percentage improvement calculated?)

 

[fnegroni]

How much better is the range with different tyres? (do you have a percentage improvement calculated?)

Haven’t calculated it properly yet, will do so over the next few hundred miles. But let’s just say so far I’ve seen something like .1 to .3 miles to the kWh better in some conditions especially wet and cold.
My latest run on mostly damp to wet motorway at 5C, 84 miles at 37mph average in 2h 26m (because I stopped to recharge and eat a panini) 3.6mi/kwh without cabin preheating or battery pre heating or intelligent battery heating. In eco drive mode and regen set to 3. Was around 3.8 to 3.9 until I stopped and sat in the car for a bit.
With OE tyres I think I would have got 3.5 at most, maybe 3.7 if I hadn’t stopped. stopping.

 

[Deleted member 17059]

I can’t find the "pre heat the battery" function on any setting.

It’s where you set charging schedule..it’s a little slide to switch it on. It’s not recommended to use it all the time..just switch on as you’re approaching a charger if you want to improve the speed of the charge,

 

[Rolfe]

Too slow to warm up ... it doesn't self-warm whilst driving and so needs "excessive" energy from the HV battery to drive the heater. Once it is warm then it'll retain the heat for quite some time, so ongoing heating would use minimal power, but the energy needed to actually heat up makes it not worth the loss of range.

That's why @fnegroni's comment re. heating whilst plugged in then using the "intelligent" mode on a long trip makes some sense. But for day-to-day usage it simply isn't worth it.

I left IBH on this morning and drove 24 miles. I was on 81% battery when I got home, I think something like 2.4 miles/kwh. Not sure what I would have got without it on. I've got something like 96 miles to do this afternoon/evening, and the return leg of the journey will probably be colder, and it's uphill to boot.

I've put Caliban back on charge just to pick up whatever he can get in the time before I have to leave again, to give a bit more leeway and reduce the chance of having to put him on the destination chargers in Glasgow during the theatre performance. So we'll see what happens this time.

(However, I just checked these destination chargers, and, oh frabjous day, they've taken the overstay fine off them! Or rather, they've extended the time allowed from four hours to a very reasonable 12 hours. This means that if I did decide to leave the car charging while I go to the theatre, I wouldn't have to trail back to unplug him before we go for our post-matinée dinner. Maybe they did read the email I sent them about this some months ago after all. The cost is still just 40p/kwh, so not a bad deal at all.)

 

[fnegroni]

I left IBH on this morning and drove 24 miles. I was on 81% battery when I got home, I think something like 2.4 miles/kwh. Not sure what I would have got without it on.

did you preheat the cabin first?
How long did it take to do those 24miles?
The IBH most likely used 1.5 to 2 kWh. What was the outside temperature during that night?

 

[Rolfe]

I didn't pre-heat the cabin, but I used the heater while driving. I left at 9.13 and got to the optician's about 9.35. I left again just before ten, and got home maybe 10.20. So perhaps 45 minutes driving in total, but split into two. Outside temperature was probably 2º to 3ºC, but the car was in the garage, not out on the drive.

 

[Rolfe]

Further update. The car went from 81% to 90% before I set off in the afternoon. I drove about 46 miles on country A roads, going through some towns and villages, and a bit of motorway (M8). Afternoon temperatures were 7º-11ºC. Got to Glasgow with an average consumption of 3.5 miles/kwh and the range showing having only decreased from 127 miles to 99 miles. SoC was 62% on arrival.

On the way back temperatures went down to about 4ºC. Consumption was noticeably poorer at 2.5 miles/kwh, giving an overall average of 3.0 miles/kwh. Got back on 25%.

All of this was with ABH enabled. Not sure if it's doing anything.

 

[fnegroni]

Thank you for the info. What’s missing from your report is: average speed of each trip, duration of each trip, time and temperature between trips. What temperature did you keep the Hvac at ?
IBH can’t do magic and won’t kick in unless the battery is at or below 10C: it takes several hours if not the whole day for the battery to cool down from say 20C to 10C if the outside temperature is 10C. Therefore IBH is at its best in the situations I described in my posts.
With the limited info you posted, however, I don’t think IBH made your consumption any worse, it might have actually improved it for the second journey in the afternoon.
I think it’s worth it as I say when the temperatures are hovering 0 or below 0.
At around 5C it’s a gamble.
If temps are on average above 5C, pre heat before a long journey or several short journeys.
Don’t preheat and don’t IBH if it’s just one or two short journeys. Eg daily commute

 

[Rolfe]

I was expecting, if anything, that the IBH would help on the way back, when it was colder, but no sign of it. By the way, the outward trip falls in elevation by 800 feet while the homeward trip has to claw that height back.

Each 46-mile trip took just over an hour. An hour and 7-9 minutes according to Android Auto. The HVAC was high - 28 or so. In between the car was in a multi-storey car park for nearly six hours and the ambient temperature was dropping from about 11ºC to 7ºC. I was getting the ice warning before I got home.

I have a trip of 14 miles shortly, with a passenger, then two hours later we come back. I'll leave the IBH on and see what happens.