Smyle Penjamin Car Key 510 Battery

Smyle Penjamin Car Key 510 Battery: A Cart Battery Built to Pass for a Key Fob

Most cart batteries look like exactly what they are. A slim pen with a glass cart on top is easy to spot on a table and easy to snap in a pocket. The Penjamin Car Key goes the other way. It looks like the remote for your car.

The shell copies a modern key fob, right down to the trunk, unlock and lock buttons. Only the middle unlock button actually works, and it handles power, voltage, preheat and firing. Your cart sits inside the body, so it rides protected instead of loose. We carry a handful of disguised batteries from Smyle Labs (the brand behind the Penjamin line), and this is the one we'd hand to someone who wants a battery that blends in next to their real keys.

Why the Car Key Stands Out

It passes for everyday carry. A key fob on a table or in a bag doesn't get a second look.

The cart rides inside. Screw a 510 cart onto the magnetic adapter, then drop it into the fob. There's no glass tank hanging off the end, waiting to crack in a bag.

Three voltages, read by color. Green is 2.7V, blue is 3.1V and red is 3.6V. Three quick clicks moves you to the next one.

Preheat for thick oil. Two quick clicks starts preheat, and the light pulses while it runs. It loosens cold or thick oil, so you don't have to crank the voltage.

USB-C charging. The port is on the bottom of the fob, and a USB-C cable comes in the box. Solid red means it's charging. Green means it's full.

Car Key Specifications

How to Use the Car Key

Charge it first with the included USB-C cable until the light turns green. Screw your cart onto the magnetic adapter (snug, not tight) and drop it into the fob. Click the middle button five times quickly to turn it on, click three times to pick a voltage, then hold the button while you draw (about three seconds per pull is plenty).

Pro Tip: Start on green, the 2.7V setting, and step up only if the vapor feels thin. Lower settings keep more flavor and stretch a cart further. If the oil is cold or thick, double-click for preheat before you reach for red.

Who the Car Key Is For

It's built for cart users who want something low-key in a pocket or bag. It also suits anyone who keeps cracking carts on skinny pens, since the cart rides inside the shell. And it makes an easy gift for someone who owns a plain black pen battery and wants one with more personality.

Care and Cleaning

Every week or two, wipe the 510 threads and the adapter with a cotton swab and a little isopropyl alcohol, then let everything dry before you reconnect a cart. Oil on the contacts is the most common reason a cart stops firing. Store it with the cart upright when you can, and don't leave it in a hot car.

Warning: Charge it only with a USB-C cable, don't fire it nonstop for long stretches, and keep it dry. It looks like a real key fob, so keep it where kids can't pick it up.

Common Questions About the Car Key

What voltage settings does the Car Key have?

The Car Key has three settings: 2.7V on a green light, 3.1V on blue and 3.6V on red. Three quick clicks switch to the next setting. We'd start thinner, flavor-forward carts on green and save red for thick oil that won't flow at the lower settings.

Which carts fit inside the fob?

Most 0.5g and 1g 510 carts fit. Screw the cart onto the magnetic adapter first, then drop it into the fob. Extra-wide or extra-tall tanks may not seat all the way, so if you run oversized carts, an open-top battery from our 510 collection is the safer pick.

How do I turn it on and use preheat?

Five quick clicks on the middle button turns the Car Key on or off. Two quick clicks starts preheat, and the light pulses while it runs. Use preheat on cold days or with thick oil instead of jumping straight to the red 3.6V setting, which burns through oil faster.

How do I charge it and read the light?

The Car Key charges through a USB-C port on the bottom, and a USB-C cable comes in the box. The light stays solid red while it charges and turns green when it's full. A blinking red light means the battery is low and it's time to plug in.

How long does a charge last?

The Car Key runs on a 300mAh battery, so it trades some runtime for its small shell. Expect to charge it more often than a bigger box-style battery, especially on the red 3.6V setting, which draws the most power. Plug it in when the light blinks red and unplug it once it turns green.

What comes in the box?

You get the Car Key battery, a USB-C charging cable, a magnetic cart adapter and a user manual. Carts aren't included. Every color comes with the same parts, and the manual lists the click patterns if you ever forget which combo does what.

Does it really look like a car key?

The shell copies a key fob, with trunk, unlock and lock buttons molded on the face. Only the middle unlock button works; it fires the battery and runs the menus. Up close you can see the Smyle logo near the bottom. The black versions look the most like a factory fob.

Complete Your Setup

Compare every option in our 510 batteries and vapes collection, or read our 510 battery guide to see how voltage and mAh change the hit. If you'd rather carry something that looks like lip balm, see the Smyle lip balm battery. Questions? Send us a note through our contact page.