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It may surprise you to know that your Tesla, and every EV, has two batteries. It has the big lithium-ion “traction” battery. But it also has a 12-volt battery like any other car. And when its battery level is truly at 0%, its 12-volt dies as well. When this happens, you can’t unlock its doors or even plug it into a charger. Luckily there is a quick fix.

What you’ll need to do is jump start the car’s 12-volt battery. But first you must get to it by opening the frunk. You’ll pop open a cover on the driver’s side of the bumper and connect a jump pack, 12-volt battery charger, or jumper cables to the positive and negative wires inside. This will short circuit the frunk latch and open the frunk.

Black Tesla with a white charger in its port, brick house visible in the background.
Tesla | Myenergi via Unsplash

Next, you’re going to remove the plastic cover on the shelf at the rear of the frunk. Beneath this, you’ll look for battery terminals. On your left (passenger side) is a positive terminal with a red plastic cover. On your right is a metal stud that is the negative terminal. Connect your jumper cables from a regular car, your jump pack, or your 12-volt charger and you can charge up the small battery.

Once the small battery is charged, you should be able to unlock your Tesla and it should also begin charging if its hooked up to a Tesla Supercharger.

Get all that? It’s OK if not, you can see the demonstration below. Then I’ll go over why some owners are seeing Tesla ranges drop dangerously.

After South Korea sued Tesla, the company admitted that the first half of its dashboard range indicator reflects “rosy” range estimates. These seem to be more in line with marketing materials than the car’s actually battery capacity.

Around the mid-point, your dashboard indicator will begin to calculate your Tesla’s actual range. So after 50%, you may see a quick drop off. This can be especially severe in cold weather or other battery draining conditions. Make sure to get used to your Tesla’s range before you try any cold drives across remote stretches of road.

Next, read more about Tesla’s range indicator subpoena, or learn more about a Model 3’s cold weather range in the video below: