Jump starting a vehicle with a dead battery has long been a courtesy drivers give to each other. But advances in electronics in modern cars mean a lot more can go wrong in this exchange. And if it does, car insurance may not cover the resulting damage.

What can go wrong when jump-starting someone’s car?

Jump starting is simple until it isn’t. A misplaced wire or bad battery in one car can cause an electrical system overload, battery damage, or overheating in one or both cars. Electrical systems in modern cars run everything — including steering, airbags, brakes and entertainment systems — so the cost of repairing any damage could go far beyond a battery replacement.

Does auto insurance cover damage from jump start gone wrong?

If something goes wrong in a jump start, your car insurance policy may not apply. It comes down to policy exclusions.

• Mechanical and electrical breakdowns: Most car insurance policies exclude mechanical and electrical breakdowns unless you buy special mechanical breakdowns coverage. This coverage is more like a warranty than traditional insurance, so most drivers never even consider it.
• Liability: Most auto insurance policies are written so that liability coverage is solely for an accident. A jump start isn’t an accident. In addition, to file a liability claim against someone, you’d effectively need to have a negligence claim that you could bring in court. A small mistake by a good Samaritan — who isn’t a trained mechanic — usually wouldn’t be considered negligence. This is true because the person providing the assistance wouldn’t have violated a duty to exercise reasonable care.

It would be very difficult to find a way to argue that either your auto insurance policy or the other driver’s policy should cover any damage to your car while jump-starting someone.

What can you do instead of jump starting?

There are three good alternatives to offering a jump start.

• Turn to the pros. Emergency roadside services offer jump starts with professional equipment and business insurance that covers the risk. You can call one out in less than an hour in most urban areas.
• See if the other drivers have tools to restart their battery. Many drivers carry portable jump-start kits, that include a separate battery and jumper cables, that can be used in place of jumping with another car.
• If you know the other driver, you can drive them to a nearby store to buy a new battery.