What is a Stop Start Vehicle (SSV)?
SSVs are sometimes also referred to as micro hybrids. They were developed by vehicle manufacturers to improve fuel efficiency and reduce emissions in line with government legislation around the world.
SSVs save fuel by shutting off the engine when the vehicle stops for a period of time (e.g. at a red light). Once the brake pedal is released the engine restarts enabling the vehicle to drive away.
Vehicles fitted with SSV technology include (but are not limited to):
- Mazda CX-5 and SP20
- Subaru XV and Impreza
- Volkswagen BlueMotion vehicles
- Audi A3 and A4
- Mercedes Blue Efficiency vehicles
- Porsche Panamera and Cayenne
- Volvo C30, S40 and V50
- BMW All 1 and 3 series with manual transmission
SSVs and batteries
While SSV technology is good for reducing emissions, it does place a higher demand on the vehicle’s battery by exposing it to a deeper discharge (and faster charge) cycle than in a conventional vehicle.
There are two types of batteries that are currently used in SSVs:
- The AGM (Absorbent Glass Mat) battery is easy to identify as it does not have any excess electrolyte. If you give one of these batteries a ‘swish’, you will not hear any liquid inside the battery. They will normally be identified on the top label with either AGM or VRLA (Valve Regulated Lead Acid).
- The Enhanced Flooded Battery (EFB), which is a new type of battery design. The best way to describe an EFB is being half way between a flooded battery and an AGM. They are constructed like a flooded battery, and have excess electrolyte in each cell (like a flooded battery).
It's important to note that installing a standard calcium battery into an SSV will result in premature battery failure - as a conventional battery is not designed to cope with the higher demands.
RAC Batteries service range for Stop Start Vehicles
RAC's AGM and EFB Batteries have been specially designed to satisfy the requirements of vehicles fitted with SSV technology.
Our AGM and EFB range is designed to handle the rigours associated with constant stop start demands, rapid recharging and the power requirements needed to run electrical accessories whilst the engine is switched off and deliver the necessary power to start the engine when the brake is released.
The range incorporates innovative design features and advanced materials to provide the cycling performance to cope with frequent discharge and recharge cycles, high charge acceptance for rapid recharge requirements in-between engine off modes and the extra power to run on board electrics whilst the engine is switched off.
RAC's SSV range offers:
- Enhanced cycling capability
- Improved charge acceptance
- Thicker battery plates
- High density active materials
- Highly durable construction
Stop Start batteries vs Conventional Systems
Stop Start Vehicle system:
- Starts vehicle on average every 1 to 2 km
- Battery operates in partial state of charge
- Accessories draw from battery when engine is off
- Rapidly recharges battery in-between engine on/off cycles
Conventional engine system:
- Starts vehicle on average twice a day
- Maintains battery in a close to full state of charge
- Accessories draw from a fully charged battery
- Recharges battery using alternator over duration of journey
Last updated October 2017