Preconditioning when charging off

Could any of you answer a query I have.

I understood preconditioning your cabin/battery while plugged into a mains charger did not impact your battery life yet I am losing roughly 5%.

Does this impact all 3i's on the same basis?

Thanks in advance.

J

You will lose some battery if it's on the occassional charger (OUC) that came with the car.

I have experienced this on my 110V OUC at home.

The charger cannot replenish the battery quick enough.

This is why I only precondition the battery when I am at work with a Level 2 charger.

The level 1 unit provided in NA is a 12A (12*120=1440W) unit. I've seen my i3 draw 20A at 240vac (20*240=4800W)(that would be limited to 30A at 120vac (30*120=3600W, and still not have the same power) during the preconditioning process. So, the additional power needs to come from somewhere...and, it comes from the battery.

Everyone here is correct. It used to drain on the battery until I had my level 2 charger installed, now it doesn't.

Regardless, according to BMW, the power used to precondition is still less than would be used under load to heat the car to the same level. It seems counter intuitive so I don't usually do it but my wife preconditions every night before leaving work. When she starts the car she can then go straight into Eco Pro mode which cuts the heating ability without freezing all the way home.

If it means the difference between riding in Comfort and Eco Pro, it is worth it to us.

FWIW, there's a new prototype battery (still in the labs) that has a third terminal that connects to a heating plate INSIDE the battery that, if it works out, would end up being much more efficient. Rather than heating up the liquid which then gradually soaks into the batteries like everyone that has this capability now uses (if I understand it correctly), heating them from the inside should be lots more efficient and faster. This tech is still probably 2-3 years away from adoption, but an interesting aside.

Unsavedone said:

Everyone here is correct. It used to drain on the battery until I had my level 2 charger installed, now it doesn't.

Regardless, according to BMW, the power used to precondition is still less than would be used under load to heat the car to the same level. It seems counter intuitive so I don't usually do it but my wife preconditions every night before leaving work. When she starts the car she can then go straight into Eco Pro mode which cuts the heating ability without freezing all the way home.

If it means the difference between riding in Comfort and Eco Pro, it is worth it to us.

Click to expand...

My guess is length of trip is a key factor. If you have <5 miles, precon is probably not worth it. If you have >10 miles, there is probably value to precon even if on L1.

NOTE: not asked here, but my understanding is the precon is limited to cabin temp when not charging at all (i.e., it doesn't use battery power to warm up the battery).

My work commute is only about 5km (when the weather is nice I walk, otherwise drive). What I find interesting is that the power drain on cold days on short trips is quite significant on EcoPro (30kWh/100km is what my app shows typically after a cold day commute). Something tells me that much of this drain is warming the pack and the cabin and that pre-conditioning, even on level 1, is worthwhile.

In the summer I can often drive for almost 2 weeks, unless i do a long trip before I feel like i should recharge. In the winter it's every few days. I live in an apartment building without charging access (and there is no EV charging at work) so the winter power drain is noticeable. My wife and I manage because we're OK being EV "pioneers" and we love our i3, but this is the kind of thing that will discourage EV use in Canada without more workplace and multi-res charging.

Thanks everyone for taking the time to reply.

J