Indications for using battery heating (now the weather is getting colder)

[JonnyG]

.........But while operating the battery it’s best to avoid for it to be below zero, and if you are asking its full performance it’s best for it to be at near ‘laboratory ambient temperature’ which is around 20°C.

Yep, that's what this guy calls the "happy goldilocks zone" for batteries and agrees with your comments ?

Worth a watch from 6'20" in :-

 

[redmg4]

Is there any way of knowing if the preheating is actually taking place once set or simply switched on from the app?
If the charging connection is left connected will the battery and car preheating draw mains instead of battery power?

 

[Martinonline]

Prior to a software update you could not pre-heat the cabin with the charger connected and the car not charging. Can't say for battery heating. If the car is charging then I believe heating will occur.

This morning I switched on the battery heating - the app slider turned blue. I listened at the bonnet and could only hear a slight pump or fan action, however the battery percentage fell over time - the car was not plugged in to my charger.

 

[Tigger]

I believe the headlights come on while it is pre-heating, and go off ten minutes later when it stops. (I wish they didn't )

 

[fnegroni]

I believe the headlights come on while it is pre-heating, and go off ten minutes later when it stops. (I wish they didn't )

Not with battery heating.

Prior to a software update you could not pre-heat the cabin with the charger connected and the car not charging. Can't say for battery heating. If the car is charging then I believe heating will occur.

This morning I switched on the battery heating - the app slider turned blue. I listened at the bonnet and could only hear a slight pump or fan action, however the battery percentage fell over time - the car was not plugged in to my charger.

The battery heater (ptc heater plus pump) emits a very faint noise but the pump vibration can be felt in the cabin at times.

 

[IJL5677]

How do you pre heat the battery from the app?

 

[jonney]

If you are charging at the time then you can see the drop in KWh in the app when the heater comes on.

 

[Martinonline]

From the home page press the battery section to get to EV Management. The battery heating slider switch is at the bottom of the page. You can also schedule it via the cog.

 

[prestonscotty]

What actually is battery pre-heating? I've seen it on the app but never known what it is.

I could probably look it up but now it has been mentioned .....

 

[Martinonline]

EV batteries like to operate within a certain temperature range. Within that range you will get the better performance. The BMS will protect the battery again at extremes but will not necessarily put you in that temperature range. Some say the benefits are debatable, certainly for longer journeys where the battery will warm through use.

Additionally using battery heating before rapid charging can decrease the time taken to charge. Again a debatable benefit if you are not in a hurry.

Search the threads for more discussion of the subject.

 

[Rolfe]

I've merged this in with an earlier thread about battery pre-heating, just to keep it all together.

 

[Photogreycat]

When do you use battery heating.

John

 

[lsb777]

When do you use battery heating.

John

Most people on the forum would probably say "never in the UK unless -10 or below" this seems to be the general consensus. It's debatable whether switching it on mid journey to pre-heat ready for rapid/Ultra-rapid charging would help as it uses a fair bit of energy. Also in this cold weather there's possibly an argument for switching it on prior to a long journey IF still plugged in. Warmer batteries hold more charge, so in theory this could help especially if able to pre-heat in a cheap tariff. Here come the responses...

 

[tsedge]

I think preheating is probably worth it if you need to Rapid charge early in your long journey or if you have a very long journey to do and want max range (so can heat while still plugged in).

The basic chemistry of the batteries mean they will perform better when warmer, in all respects.

However, definitely not worth it for short journeys.

 

[Rolfe]

A bit more merging, to save people having to repeat themselves!

 

[Adammac39]

Is it beneficial to pre heat the battery before driving ? If so how long before driving should I heat it for?

Or is the pre heating just used before fast charging?

 

[fnegroni]

there are plenty of threads on the subject, and no definitive guideline other than you should preheat the battery before a) charging at a DC charger or b) a long journey where you are likely to want to access the full capacity of the battery or c) you want to access the car’s full power potential immediately or c) it’s below 0 degrees Celsius.

As for how long to preheat this depends mainly on the battery pack you have: the bigger the pack the longer it might take for the temperature to be even throughout the whole pack: anything between half an hour and 1 and half hour
Or if you have an LFP battery, I’d say preheat half an hour to one hour before setting off.

Future battery packs are likely to be submerged in coolant and will take much less time to warm up or cool down thanks to the coolant reaching all corners of all cells.
Most batteries aren’t cooled or heated that way and it takes time for heat to transfer between the battery pack and the coolant

 

[Rolfe]

Hi @Adammac39 and welcome.

I'm merging this in with other threads on the topic to keep it all together. If you have a read up the thread I think you'll find some helpful advice. (Or I hope you will, it still confuses me a bit.)

 

[Tig170]

As someone who has done 20k miles on an LFP battery (+ home battery storage) - my battery status is down to 95% via car scanner/ ABRP - but the reduction is so much down to mileage (the graph to 'unoficial' SOH to mileage is linear), I'm not so sure if this is 100% correct, as have seen over 220miles in the display at 100%. At home I've just gone to 99% in the same time period, with home battery storage. Personally I've just forgotten battery heating, as without it, in recent weeks around scotland, we averaged 3.3Kw/mile - total cost was £200 (mainy tesla, with CPS) for 2000 mile round trip

 

[Adammac39]

Thanks for this. I’ve only had the car about a week so just getting used to things. I’m currently averaging about 3.2 on a 22 mile journey to work, but it takes about 3 miles for it to start averaging things out. I didn’t know if pre-heating the battery helped with me getting a better M/kwh.