i3 Preconditioning Facts

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TomMoloughney

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Aug 6, 2012
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694
Location
New Jersey
There have been a lot of questions here and elsewhere on how the i3's preconditioning system works. I sent a list of questions that I found on various sites to BMW for answers so I could put them all together in one place as a reference for i3 owners. Take a look and please add comments if you have any other questions or information that I left out.

http://bmwi3.blogspot.com/2015/03/bmw-i3-understanding-how.html
 
Nice post - thought I knew everything but not the 3 hour limit. I've user the iRemote app a few times on the way back from shopping whilst parked at a public chargers thinking well if the battery gets 15 muinutes to warm up... nevermind at least the car was toasty.


I've got a couple of questions that I've been trying to find answers for...

1) I haven't yet got around to experimenting with this yet as I leave before the end of cheap rate electric, but what is the relationship between the timer for low rate electricity and the preconditioner. Eg. you might have programmed off peak between midnight and 7am, but have a departure time set of 8.30am. (I wish). In that case would a) the charge timer allow the battery to be topped up if the off peak charging is set b) the battery run down c ) would preconditioning be stopped at the end of cheap electric? Of the choices... I'd prefer a.

2) What happens if you are a bit slow getting dressed / breakfast / out of the shower and don't make the departure time. From my experience of this (like every day) it seems to keep the heat goign for about 15 minutes and then stops. Not sure of the exact time but I was really late one day and the car had cooled off again! LOL. Just wondering a) what the timeout is and b) if there's a way to say "keep the battery warm I'll be there in 10 minutes" given the 3 hour limit already mentioned. Probably not such an issue given the thermal mass of 230kg of LiIon, and hte cabin can be triggeredf from the iRemote once you finally head off to clean your teeth. ;-)

3) The pre-conditioning sends my EVSE into a clunking clicking cycle about every 30 to 60 seconds. I'm assuming the car is requesting current from the EVSE, reaching 100% again and then telling the EVSE - that's enough. Is it just my EVSE that's clunks or do all of them do it? (Rolec 240v 32a with a socket not tethered).

4) Last one - for the first time today - I went out to the car and the battery was not fully charged - was at 75%. Don't know what had happened. The pre-heat was working - the EVSE was supplying power and clunked as I unlocked the car. It definitely took on some charge, as I left it last night at 50%. Checked all settings like charge rate and timers (Max on both Standard and Fast Chargers, Off peak 11:30pm - 7am, Departure 6.15 Precondition on) and can't see why it would have either not charged or dropped charge. Does this sound like a known issue? I've had one where the car charges to 100% when plugged in despite being told to wait till off peak. Wasn't the end of the world - I went the "Fast" way to work on the M6 motorway (UK) and stopped off at Corley Rapid CCS. One that actually works! 50% on arrival - 80% 19 minutes later and back on my way. As the route is 15 minutes quicker than the shorter back roads not much time lost :)
 
On 2 I noticed the same but as you say battery is bigger area, and even when the cabin had cooled in my case, the battery was still at 10degrees. The timeout is 15mins, and you can check battery temp from the service menu.

On point 3, the cycling of EVSE has been reported but I don't think a proper fix is expected until November.

I have also had a weird not charge with Rolec, in my case it was because the connection wasn't registered properly, I am untethered and hadn't pushed the type2 into the unit far enough, it was in far enough to make contact with signal pins.

In the last firmware update I have 14-11-504, the behaviour changed when plugging in, it seems to request about 20 seconds of power to confirm the connection before sleeping until off-peak.
 
nowtta60 said:
1) I haven't yet got around to experimenting with this yet as I leave before the end of cheap rate electric, but what is the relationship between the timer for low rate electricity and the preconditioner. Eg. you might have programmed off peak between midnight and 7am, but have a departure time set of 8.30am. (I wish). In that case would a) the charge timer allow the battery to be topped up if the off peak charging is set b) the battery run down c ) would preconditioning be stopped at the end of cheap electric? Of the choices... I'd prefer a.
What I observe happening is that if you have a late day departure set (for me, today at 17:20) and have the vehicle fully charged overnight with off-peak, then go out in the car for a few miles and plug it in when you return, it realises you have a departure but with no off-peak possible, so charges immediately anyway. It will then pre-condition before departure. It also pre-conditions on "normal" electric if it's not used between fully charging overnight and departing late afternoon.

So I would expect that you would see it charge to 100% on low-rate, but then pre-condition with "normal" electric before you depart.
 
I don't have my level 2 charger installed at my house yet, so when I plugged into a Chargepoint charger yesterday morning before church, I figured I would try setting up preconditioning. I set it up with a departure time of 12:24 pm, a little more than 3 hours later than the then current time of 9:17 am. My Android iControl app stubbornly refused to take 12:24 pm, instead changing it to 12:24 am. Times after 1 pm were not affected in this way. Bug, or something I'm not fully grasping?

As a side note, as it happens, the preconditioning probably wouldn't have worked anyway, because I've learned that this particular public charger has a 2 hour limit.
 
Something is missing in the FAQ:

preconditioning only happens if you don't iremote it ( ask for it ) under a certain number of times that were followed by a real start. If you ask for it and you do not use the preconditioned car, it won't preconditionned it after a number of times. You will get a message on the car like " The car wasn't preconditioned because it was not used after too many preconditioning"

Probably so that you don't use too much of electricty if you had put a schedule and you were on holiday, or something.

I discoverd that when trying to put it at 100% in the winter. By preconditioning a couple of times in a row, i was able to warm the batteries-cabin to a point where the second preconditioning was able to charge the batteries since they were already warm. But at a point, the command did not work. I got the message of too many preconditioning without using the car. Same after some days in a row preconditioning schedule without using the car.

Louis
 
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