Support battery
The vehicle is equipped with a support battery that helps during the Start/Stop function's start sequence.
The battery is either a 12 V battery or, if the vehicle is a mild hybrid*, a 48 V battery that also enables regenerative braking while driving.
Location
![P5-1617-S90/V90 Support battery location](https://www.volvocars.com/images/support/imgb960d13ee0d39ed4c0a8015272ed245b_1_--_--_VOICEpnghigh.png?imwidth=1280)
![P5-1917-XC90-48V battery](https://www.volvocars.com/images/support/imgc3e83dbb42c6beacc0a8015225994c5f_5_--_--_VOICEpnghigh.png?imwidth=1280)
Maintenance of support battery
The support battery does not normally require more service than the start battery. If you have any questions or concerns, consult a workshop ‒ an authorized Volvo workshop is recommended.
Important
If replacing the 12 V battery, make sure you replace it with a battery of the same size, cold start capacity and type as the original battery. Volvo recommends having an authorized Volvo workshop change batteries.
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.
Specifications for support battery
If the vehicle is a mild hybrid*, the support battery is a 48 V lithium-ion battery.