Range and warm weather

[Kristian]

Got my best range out of a single charge last week - 145 miles with 6 miles left in the battery (94Ah BEV).
Had the aircon on all the way there only to find the destination charger was broken - had used 50% charge to get there.
drove more slowly on the way back with no aircon (except for last 15 minutes when it became clear we would make it home OK)
outside temperature was 30 degrees C.
It would be nice if there was an option to precondition the battery to a higher temperature if you need maximum range rather than the 13 degrees C (approx) that it currently does

 

[jadnashuanh]

During use, the battery warms itself. LiON batteries do lose capacity when cold, but not as much as say lead acid ones, so there's a tradeoff as to what temp to warm them is enough without wasting a lot of energy. If they get too hot during use, then, more energy is required to run the cooling to keep them out of their danger zone. In the US desert southwest, Nissan Leafs have had a big issue with being too hot on their batteries, but the vehicles with active cooling have not, at least to the extent Nissan has with their battery design and tech. So, I'm not sure warmer is better in this instance.

BMW has said that running with the windows open at speeds above 25mph is less efficient than running with them closed and the a/c on because of the added drag...to become more efficient, the best solution is to drive slower and more steadily. One of the eco modes will help you do that, as it also minimizes the a/c use, but still runs it. Note that when it's hot, the a/c is still likely running to keep the batteries cool if you're driving fast in hot weather.

 

[user 4543]

Interesting discussion, re. UK chargers, a significant proportion of the rapid network are unserviceable at any time- I always have a 'plan B' for long trips.

But last Saturday 2 of 3 rapids were u/s and the 3rd was busy, so I had to REX for 20 miles.

Based on my experience, I'm not currently recommending an electric car to any of my friends, despite my satisfaction with my i3 (94Ah 2016)

Chris

 

[Kristian]

During use, the battery warms itself. LiON batteries do lose capacity when cold, but not as much as say lead acid ones, so there's a tradeoff as to what temp to warm them is enough without wasting a lot of energy. If they get too hot during use, then, more energy is required to run the cooling to keep them out of their danger zone. In the US desert southwest, Nissan Leafs have had a big issue with being too hot on their batteries, but the vehicles with active cooling have not, at least to the extent Nissan has with their battery design and tech. So, I'm not sure warmer is better in this instance.

BMW has said that running with the windows open at speeds above 25mph is less efficient than running with them closed and the a/c on because of the added drag...to become more efficient, the best solution is to drive slower and more steadily. One of the eco modes will help you do that, as it also minimizes the a/c use, but still runs it. Note that when it's hot, the a/c is still likely running to keep the batteries cool if you're driving fast in hot weather.

Much over 30°C then the battery won't like it.
When I started to charge the car at the end of the day on my trickle charger (240v @ 10amps) I did hear fans start under the bonnet (hood) but only for a few minutes.

I knew about open windows causing drag but guessed the switch over point would be nearer say 50mph - I'll have to use the AC a bit more instead

 

[Kristian]

Interesting discussion, re. UK chargers, a significant proportion of the rapid network are unserviceable at any time- I always have a 'plan B' for long trips.

But last Saturday 2 of 3 rapids were u/s and the 3rd was busy, so I had to REX for 20 miles.

Based on my experience, I'm not currently recommending an electric car to any of my friends, despite my satisfaction with my i3 (94Ah 2016)

Chris

My plan B was drive slower on the way back - Having to change your driving style is probably why pure electric vehicles are still rather niche. I would only recommend a BEV if you can plan most of your driving in advance like commuting and you do enough miles to recoup the purchase price - I did about 20,000 a year in mine before Corona.

 

[jadnashuanh]

95% of all my driving can be done on my 2014 i3 BEV. Should I need to go further, or carry more, I have an ICE that gets used infrequently. But, to simplify things a bit, I have an X5 45e on order, and while it certainly won't be as easy to park! it will let me go a long time in between needing to buy petrol, but not have the issues about trying to find a working CCS or EVSE unit along the way. When that comes in (delayed because the seats I wanted are backordered), I'll sell my two existing vehicles. Means I can keep it in the garage, too, which makes it better in the winter because of snow. I'll miss the i3 when that happens, but the allure of a new vehicle is pretty high, too! The X5 will allow remote cabin conditioning and you can set a departure time to warm the batteries, if useful, too.