Do you really charge the battery to 100% when going on vacation?

If it is me going on vacation. I would charge to 100%. Then park it so that i can get it tow if anythnig wrong. And unplug any chargers from the wall, etc. The car not starting when back will be secondary issue if it does happen.

 

I guess I don't understand why you would charge to 100% and leave it sit for a while. I mean having it sit at 80% seems like it would be just as well and not have the battery sitting at a max...

 

100% on the SE is roughly equivalent to 80% for other BEVs. The SE has a built-in top buffer that provides automatic overcharge protection.

 

For a week it doesn't matter.

 

I speculate MINI's guidance intends to ensure the 12V battery doesn't go flat after prolonged idle times.

I haven't noticed any "vampire drain" with the high voltage battery after 5-7 days of sitting idle without charging.

 

I am quite sure that 100% is 96%. I am sure charging to 100% every day won't make a huge difference, but I personally wouldn't leave it with a high state of charge for a long period of time. I would leave it with 60-80%. I barely looses anything when parked.

There are many different opinions on this topic though..

 

This question should not be a issue. If you think about after these cars are built they will sit on a lot somewhere maybe up to 30 days waiting to go on a ship. Then when they arrive in the US they will be moved from point to point w/o being charged. Then once at a dealer may sit on their lot for however many days it takes them to sell it. So many, many, many days w/o being charged.

 

In -20F weather I've seen 1-2% loss for the week. Charging to 100% (and left unplugged) will just help top off the 12V battery.

 

I parked mine under a car port and a cover for four months. It was still 100% when I pulled the cover a couple weeks ago to go for a ride. Dunno the state of the 12V battery, didn't seem to be any different.

 

It should be fully charged. Your SE will notify you if the 12 V battery is being drained, which I know from experience.

 

Yup, charged the SE to 100% and left it in the garage for a month when we went away, came back and it was still 100%. Was also monitoring it through the app while we were away, just curious if the SOC will degrade.

 

Last I checked the battery had 28.9 kWh usable out of 32.6 kWh total. So 12% total buffer divided between the top and bottom.

 

I just wanted to make a quick note about the “buffer” capacity. A battery is not like a gas tank, which has absolute full and empty points. The battery manufacturer decides minimum and maximum nominal voltages for the battery, and the battery’s nominal capacity is what you should get if you discharge from the max voltage to the min voltage. There’s nothing preventing the battery from charging or discharging to above or below these voltages, it will just result in a larger capacity and a shorter lifespan for the battery than the manufacturer specifies. Likewise, the battery’s lifespan can be increased and capacity decreased by setting more conservative voltage limits. MINI has evidently chosen to set more conservative voltage limits than the battery manufacturer, resulting in a smaller usable capacity than the battery’s nominal capacity. You might be able to extend the lifespan further by keeping the battery to an even tighter voltage range, but at some point, you’ll reach a point of diminishing gains.

I don’t know much about the MINI’s particular battery chemistry so when I go on a trip I usually leave it at 80-90% in hopes that it’ll extend the life a bit longer. But I leave mine plugged in most of the time so that probably doesn’t make a difference.

 

E

Every trip with the mini is a vacation, so yeah of course I “Always Be Charging.”

real talk though, maybe charge to only 90% for extended parking. The battery buffer is somewhat software limited but it’s not great to leave EV’s at 100%.

 

How could that be, i.e, charge to 100% be around 80% of the battery gross capacity 32.6 kWh, when the net capacity is 28.9 kWh?

I would really would like that such was the case, but it does not seem so. Furthermore, that I presume that a bottom buffer also exists.

 

Were you able to check the status of the charge overtime with the App?

How didi you manage that?

I ask such, as my App only reports the status of the car as the time I closed it, and there are no further updates from that date. Unless and of course, I give some instruction from the App to the, like closing/opening, changing of peak charge profile, start conditioning,...

 

While not officially confirmed until someone does a teardown, I would reckon the CATL cells are very similar to the Samsung SDI 94Ah BMW i3 chemistry of the very conservative NCM 333 (NCM 622 for the 120Ah i3). Many automakers have already moved onto NCM 811 or 9-0.5-0.5 to really market the maximum range at the expense of cathode stability and much shorter lifespans. That may change with manganese aluminum oxides or presumably solid state for BMW Neue Klasse 2025 platform.

 

I hope a couple of battery generations down the line the aftermarket will offer two optional replacements for our SE battery: lighter-weight and longer-range. If it could lop off 200 lbs, I'd choose a lighter, 110-mile battery.