A viral video shows a jump start gone wrong — here’s how to do it safely
A viral video shows how fast a simple jump start can go wrong and why proper technique matters.
Things can happen, and anyone who has driven for a while knows that in some cases, the car needs a jump start. It can be due to an electrical failure, but most of the time, it is just an old battery giving out.
A routine jump-start is supposed to be one of the simplest roadside fixes, but when done incorrectly, it can damage electrical systems or pose a safety hazard.
A recent viral TikTok video shared on Reddit showing a failed attempt went viral, illustrating how quickly a small mistake can turn into an expensive problem. As modern vehicles become more electronically complex, understanding the correct procedure and knowing when not to attempt one at all has become increasingly important.
The Story
On Reddit’s r/ElectroBOOM forum, a user posted a video of witnessing a jump-start attempt that went wrong.
In the video, two cars are connected with a jump-start cable as smoke rises from one of them. The wires were likely connected wrongly, which probably caused a short circuit; then the plastic started smoking, and the cable began melting.
This attempt likely killed both batteries, and even though we can’t see the end, it might have even started a fire.
Several peopel reacted to the post and many explained how to avoid a situation like this.
How to jump-start a vehicle correctly
First, ensure both vehicles are positioned about 18 inches away. Engines turned off and parking brakes on. Inspect the disabled vehicle’s battery for signs of leaks or damage. If any present, do not attempt a jump start.
If all looks good, attach jumper cables in the correct sequence: connect the red (positive) clamp to the dead battery’s positive terminal, then to the donor battery’s positive terminal. Next, connect the black (negative) clamp to the donor battery’s negative terminal. Finally, attach the remaining black clamp to an unpainted metal surface on the vehicle with the dead battery. Not its negative terminal. This last step helps avoid sparks near the battery and reduces the risk of explosion from hydrogen gas accumulation.
Start the donor vehicle engine and let it idle a minute or two to build voltage. Then attempt to start the disabled vehicle. If it fails, wait longer rather than repeatedly cranking the engine. Once the vehicle starts, keep both engines running for a brief time. Disconnect the cables in the reverse order of connection, starting with the black clamp on the now-running vehicle, then the black clamp on the donor, then the red clamp on the donor, and finally the red clamp on the revived vehicle.
According to experts, disconnecting the cables in the wrong order can cause sparks and electrical surges that may damage sensitive components or blow fuses. It’s also crucial to ensure the metal clamps do not touch each other at any point during the process, as this can cause dangerous arcing.
After the cables are removed, drive the jump-started car for at least 15-30 minutes so the alternator can recharge the battery. If the vehicle struggles to start again shortly after, the battery or charging system may be failing, and professional service is needed.
Jump-start electric vehicles
Although electric vehicles primarily draw power from a high-voltage battery pack, they also include a conventional 12-volt battery that supports the vehicle’s electrical systems and accessories. If the 12-volt battery becomes discharged, a jump-start is possible but only under the correct conditions.
The assisting vehicle must also have a 12-volt battery and a negative-ground system (as is typical in gasoline-powered cars). An EV should never be used to jump-start another vehicle because the EV’s low-voltage system is designed only to power its own systems and not to jump-start an engine.
When jump-starting the EV, the cars should be parked close enough that the cables reach both batteries. Both vehicles must be switched off and in park with parking brakes engaged. All accessories (lights, infotainment, climate controls) should be turned off in both vehicles. The red (+) jumper cable is connected first to the depleted battery’s positive terminal, then to the assisting vehicle’s positive terminal.
Then the black (–) cable is connected to the donor battery’s negative terminal, and finally the black cable is attached to a grounded, unpainted metal surface on the EV — not directly to the depleted battery’s negative terminal.
Once connections are secure, start the donor vehicle and allow it to idle to build voltage. Then try to start the EV. After the EV begins, the jump cables should be kept connected for several minutes to allow the system to stabilize. Then remove in the reverse order of connection to avoid electrical short-circuits. Finally, the jump-started EV should be driven or kept running for at least 20 minutes to help the 12-volt battery recharge via the vehicle’s electrical system.
Takeaway
The jump-start shown in the viral video may look like a simple mistake, but it illustrates a broader point: modern vehicles are less forgiving of errors than their older counterparts. A dead battery is still frustrating, but following the correct procedure or calling for professional assistance when dealing with hybrids or EVs can prevent a costly repair. When in doubt, it’s best to call for roadside assistance.
