e-HDi eco mode battery voltage

[onix45]

Hello,

Does anyone know at what battery voltage the start-stop function stop working because the battery is considered too low?
For some reason i think it was 12,5V but i am not certain.

Or is it related to the battery charge percentage? I do recall the threshold being 75% cahrge, but surely there has to be an equivalent voltage for 75%?

[GiveMeABreak]

I think it's a little more involved than that to be honest. For example, when operational, the system will automatically restart the engine in the following conditions:

• Inadequate vacuum reserve
• Vehicle speed above 8 km/h for a vehicle fitted with a piloted manual gearbox
• Vehicle speed above 25 km/h for a vehicle fitted with a manual gearbox
• Lowering of the temperature of the Lambda sensors
• Thermal protection of the alternator
• Thermal protection of the battery
• Thermal protection of the voltage retaining device ECU
• Battery charge status below 73%
• Battery charge status becomes non-nominal
• Battery voltage below 11,8 V for 1 seconds
• Power accumulator voltage below 4,7 V
• Engine requirement (*)
• Power steering system downgrade mode

If the following are true then the engine will not start automatically.

• Traction chain closed
• Power accumulator charge status inadequate
• Low battery charge status

The Stop Start will not stop the engine if the battery charge status is below 75%, you have undertaken 6 stops in the previous minute or a host of other factors.
If you have a fault or warning light there will be a fault code you can read with Lexia - that will help us with diagnosis.

[onix45]

Nah, its fine, it just wont stop the engine. because the battery is pretty old. I drive most of the time in the city, but it used to be that after driving out of town somewhere the start-stop would start to engage again for a day or two. But now this is not the case anymore, even after a long journey. So i am just wondering if it is time to change the battery. The car starts fine and there are no other signs of a weak battery, but i will see what happens when winter comes and i'll have to start it in the morning.

[GiveMeABreak]

Ok, these are the conditions that have to be met for the engine to stop when using the system - there are USER conditions and SYSTEM conditions:

User conditions allowing the engine to be stopped:

System conditions allowing the engine to be stopped:

Stop and start function activated Cabin temperature corresponding to the driver’s requirement Brake pedal applied or changing into neutral position with a vehicle speed below 6 km/h (Piloted manual gearbox) Gear lever in neutral, clutch pedal released and vehicle speed below 20 km/h (Manual gearbox) Driver’s belt fastened Driver’s door closed No pressing of the accelerator pedal No deicing/demisting of the windscreen

Electrical power sufficient to permit restarting of the engine Vehicle speed has exceeded 10 km/h since the initial starting There has been an interval of at least 4 seconds between 2 engine stops There has been an interval of at least 2 seconds since the previous restart Adequate vacuum reserve Fuel temperature below 60°C Alternator temperature below 130°C Battery temperature between -5°C and 60°C Power accumulator temperature below 55°C Voltage retaining device ECU temperature below 90°C Battery charge status above 75% Fewer than 6 restarts per minute No regeneration of the particle emission filter in progress Power accumulator voltage insufficient(4,7 V) Internal resistance of the battery below 5,6 m? No regulation by the dynamic stability control system Exceed 10 km/h after application of the electric parking brake No power steering system downgrade mode Altitude below 1700 metres for vehicles fitted with the DV6C engine and a piloted manual gearbox Absence of engine requirements (*)