Jump starting using another battery

Updated 2024-10-17

If the start battery is discharged, current from another battery can be used to start the vehicle.

Jump-starting requires access to another vehicle's 12 V battery and jumper cables.

Important

The charging points in mild hybrid vehicles are only intended for jump-starting your own vehicle. Don't use the charging points on mild hybrid vehicles to start other vehicles – the charging circuit's fuse could be overloaded and stop working.

In mild hybrid vehicles, a discharged start battery can be caused by an overloaded fuse that is preventing charging. If the fuse has blown, 12 V battery fuse failure Service required will be displayed in the instrument panel. Volvo recommends contacting an authorized Volvo workshop.

P6-1817-CMA-XC40-starter cable fixation points — Jumper cable charging points. Engine compartment appearance may vary depending on vehicle model and equipment level.

To avoid short circuits or other damage, the following steps are recommended when jump starting the battery using another battery:

Put the ignition in mode 0.

Make sure that the assisting battery has a voltage of 12 V.

If the battery is in another vehicle, turn off that vehicle's engine and make sure that the vehicles are not touching each other.

Clamp one end of the red jumper cable to the assisting battery's positive terminal (1).

Important

Connect the jumper cable carefully to prevent short circuit and contact with other components in the engine compartment.

Fold back the cover over your vehicle's positive charging point (2).

Clamp the other end of the red jumper cable to your vehicle's positive charging point (2).

Clamp one end of the black jumper cable to the assisting battery's negative terminal (3).

Clamp the other end of the black jumper cable to your vehicle's negative charging point (4).

Make sure the jumper cable's clamps are securely attached. Poor contact can cause sparks or the clamps to loosen during the start attempt.

Start the engine of the assisting vehicle and let it run for a few minutes at a higher idling speed than normal, about 1500 rpm.

Start the engine of the vehicle with the dead battery.

Important

Do not touch the connections between the cable and the vehicle during the start attempt. Risk of sparking.

Remove the jumper cables in the reverse order ‒ first the black cables and then the red cables.

Make sure that none of the clamps of the black jumper cables come into contact with the vehicle's positive charging point, the assisting vehicle's battery's positive terminal, or either of the red jumper cable's connected clamps.

Warning

Mild hybrid vehicles have components that work with 48 V voltage, which can be dangerous if handled incorrectly. Do not touch components that are not clearly described in the Owner's Manual.

Never use a 48 V support battery to jump-start the vehicle.
External electrical equipment may not under any circumstance be connected to the 48 V battery.
Only a workshop may replace or perform service on the 48 V battery – an authorized Volvo workshop is recommended.

Warning

PROPOSITION 65 WARNING! Battery posts, terminals, and related accessories contain lead and lead compounds, chemicals known to the state of California to cause cancer and reproductive harm. Wash hands after handling.

Warning

Batteries generate hydrogen gas, which is flammable and explosive.
Do not connect the jumper cable to any part of the fuel system or to any moving parts. Avoid touching hot manifolds.
Battery fluid contains sulfuric acid. Do not allow battery fluid to contact eyes, skin, fabrics or painted surfaces.
If contact occurs, flush the affected area immediately with water. Obtain medical help immediately if eyes are affected.
Never expose the battery to open flame or electric spark. Do not smoke near the battery. Failure to follow the instructions for jump starting can lead to injury.

Note

If the starter battery has such a low charge level that the vehicle does not have normal electrical functions and the engine must then be jump-started with an external battery or a battery charger, the Start/Stop function may remain activated. If the Start/Stop function shortly thereafter auto-stops the engine, there is a huge risk that auto-start of the engine will fail since the battery had not had time to recharge sufficiently.

If the vehicle has been jump-started or if there has not been enough time for the battery to be charged with a battery charger, the Start/Stop function should be temporarily deactivated until the battery has been recharged sufficiently. At an ambient temperature of about +15 °C (about 60 °F), the battery must be charged by the vehicle for at least 1 hour. At lower ambient temperatures, the charging time can increase to 3-4 hours. The recommendation is to charge the battery with an external battery charger, if possible.