Preconditioning your BMW i3 EV

If you own a BMW i3, preconditioning is an important part of getting the most range on frosty winter mornings. Without it, your car is freezing cold when you get in to go to work. That’s bad enough, but even worse is that your range may be cut by as much as 20% if your battery pack is not properly warmed up. You can select the preconditioning mode from your smart phone. Do that while your morning coffee is brewing and your good to go, right? Actually, its more complicated than that.

BMW i3 owner Tom Moloughney lives in New Jersey, where sub-zero mornings were common this winter. He decided to delve into his owner’s manual to make sure he was doing all the right things to precondition his i3 properly. But he still had questions, so he asked his dealer for help, only to find the dealer was just as confused as he was. That’s when he turned to BMW’s top US technical services manager. Then he added a post to his i3 blog explaining all he had learned so other i3 owners would have the latest and most accurate information. Here’s what he found out.

If you set up preconditioning from your smart phone app, only the cabin heater is activated unless you also set the departure time and then enable “preconditioning for departure.” Now this part is critical. The departure time must be at least 3 hours after you enable preconditioning. It takes the car that long to get the battery up to proper operating temperature.

This is important enough to repeat. Select “preconditioning” using your remote app and you get a warm cabin but a cold battery. Select “preconditioning for departure” but start driving less than 3 hours later and the battery will not be fully warmed up and your range will suffer.

If your i3 is not plugged in, the cabin heater will operate during preconditioning but no heating of the battery will take place.

If you are using a Level 1 charger, the preconditioning draws more power than the charger can supply, so your battery will not be fully charged when you start driving. You need a Level 2 charger to precondition the car and fully charge the battery.

The car will not start warming the battery no matter how cold it gets outside unless you activate the preconditioning process. It does not happen automatically even if the car is plugged in.

The optimum temperature range for the battery is between 77 and 104 degrees Fahrenheit. Above that temperature, the battery cooling process will operate during preconditioning mode, but BMW says that situation is rare because of where the battery is located.

Let’s recap. Preconditioning is necessary in cold conditions to maximize battery range. Just hitting “precondition” on your cell phone app does not turn on battery warming. You have to select “precondition for departure” and set a departure time at least 3 hours in advance for the battery warming process to operate.

The smartest way to make sure you get maximum range on cold days is to plug in your car and enable the “precondition for departure” function before you go to bed at night. The car will automatically start heating the battery 150 minutes prior to departure. Cabin heating begins about 40 minutes before you are scheduled to leave. Having a pre-warmed cabin means you can turn the heat down while driving and extend your range even more.

Thanks to Tom Moloughney for digging deep for this information and sharing it.