It’s dark, it’s cold, and your car won’t start. Or maybe you just felt the thump of a flat tire on a road with no shoulder. Most roadside problems aren’t dramatic, but they feel a whole lot worse when the trunk is empty.
So what should you keep in your car for roadside emergencies? Start with a portable jump starter, a tire inflator with a gauge, a flashlight, and some visibility gear like reflective triangles. Then add water, a blanket, and a phone charger to match your climate. A small kit like that can turn many breakdowns into a 20-minute inconvenience.
Start with the essentials for the most common problems
Dead batteries and flat or low tires are among the most common roadside problems, so those two get top priority.
A way to jump-start the car
Jumper cables work, but they need a second vehicle and a willing stranger. A portable jump starter lets you restart the engine yourself, which is a big plus on a quiet road or in a parking lot at night. Engine size matters here. Larger gas engines and diesels need more starting power than a small car, so match the jump starter’s rating to your engine. Drive a heavy-duty rig? Check out our guide to portable jump starters for diesel trucks.
A few safety basics for jump-starting:
- Read both the jump starter’s manual and your vehicle’s owner’s manual first.
- Don’t try to jump a battery that’s cracked, leaking, or frozen.
- Connect the clamps in the correct order, and never let them touch each other.
- Keep sparks and flames away from the battery.
A tire inflator and a gauge
Slow leaks are common, and being able to add air can get you to a shop safely. A 12-volt inflator that plugs into your car’s accessory outlet is compact and handy. Pair it with a digital gauge, which makes it easier to hit the right pressure. That number is printed on the sticker inside your driver’s door jamb, not on the tire sidewall. Our roundup of portable tire inflators with a digital gauge explains what to look for. Keep in mind that an inflator is meant for slow leaks and low pressure, not for a tire with a large puncture or sidewall damage.
Know your spare-tire setup
Next, check that your spare is inflated and that you have the jack and lug wrench. Many newer cars come with a compact spare, or an inflator-and-sealant kit instead. Take a few minutes at home to find these items and read the instructions, because the roadside is a terrible place to learn the jack is missing.
Safety and visibility items for your car
Once the car’s moving again, or while you wait for help, you want other drivers to see you. These items do the job:
- Reflective warning triangles or LED flares. They make you visible to approaching traffic, especially on curves or at night.
- A reflective vest. It’s useful if you have to step out on a busy road.
- A flashlight with spare batteries, or a headlamp so your hands stay free. Don’t count on your phone’s light, since it drains the battery you need for calls.
- A basic first-aid kit. Pack bandages, gauze, antiseptic wipes, and any personal medications you might need.
- A fire extinguisher rated for vehicle use, mounted where you can reach it.
What if you break down on a highway? The usual guidance is to move the car off the road if you can, turn on your hazard lights, and either stay buckled in or move well away from the traffic lane, depending on the situation. When in doubt, call for help and stay wherever you’re safest.
Comfort items for a long wait
Say you’re stuck for hours in extreme weather. That’s when these small items earn their space:
- Water and a few non-perishable snacks. Swap them out each season, since heat and cold take a toll.
- A warm blanket and gloves, plus a hat in winter climates.
- A phone charging cable and a power bank. Recharge the power bank every few months.
- In snowy regions, a small shovel, an ice scraper, and traction aids like sand or kitty litter.
One safety note: if you run the engine for heat while you wait, keep the tailpipe clear of snow and mud and crack a window. A blocked exhaust can let carbon monoxide build up inside the car.
Basic tools worth carrying
You don’t need a full mechanic’s chest. A short list covers most quick fixes:
- A multitool, or a small adjustable wrench and screwdriver set
- Duct tape and zip ties for temporary repairs
- A tire pressure gauge
Want to build up your home toolbox too? Our list of the tools every new homeowner should own makes a good companion.
How to prevent a dead battery in the first place
The best roadside emergency is the one that never happens. If a vehicle sits for weeks, like a second car or an RV, its battery slowly loses charge, and a battery left drained for long can be damaged for good. A smart charger or maintainer keeps it topped up and helps it last longer. Different battery types, such as AGM, need compatible charging profiles, so check what yours requires. Our guide to smart battery chargers for AGM batteries covers the options. And if your battery is more than a few years old, have it tested at an auto parts store or shop, since weak batteries tend to quit on the first cold morning.
How to store your emergency kit
A small bag or a collapsible trunk organizer keeps everything from rolling around. Put the things you’d need most urgently, like the flashlight and triangles, on top. Keep heat-sensitive items, like some batteries and aerosol cans, out of a hot summer trunk. Then review the kit twice a year (when the clocks change is an easy reminder) and replace anything expired or worn.
Frequently asked questions
What are the most important things to keep in a car for emergencies?
A portable jump starter, a tire inflator with a gauge, a flashlight, and reflective triangles cover the most common problems. Water, a blanket, and a phone charger are smart additions for longer waits.
Is a portable jump starter better than jumper cables?
A portable jump starter lets you restart the car on your own, while cables need a second vehicle. Just make sure its rating fits your engine, since larger gas engines and diesels need more power.
How often should I check my roadside emergency kit?
Twice a year is a good habit, and the clock change makes an easy reminder. Replace expired snacks, weak flashlight batteries, and anything worn, and recharge your power bank every few months.
The bottom line
For a car emergency kit, begin with a jump starter, a tire inflator with a gauge, a flashlight, and visibility gear, then add comfort items for your climate. If something on a list isn’t something you’d really use, skip it. The roundups linked above can help you compare jump starters, inflators, and battery chargers. And for planning beyond the car, our power outage checklist helps you get your home ready too.