This used Battery Charge State Control Unit (BSM) is designed for a range of Citroën and Peugeot models and is commonly searched by its OEM numbers 9676592280, 9802043580, 6500KV. The unit monitors battery state of charge and communicates with the vehicle charging system to optimise alternator behaviour and protect vehicle electronics. Ideal for professional workshops and DIY mechanics who need a reliable replacement module to restore correct charging management and electrical stability.

Technical Information

• Manufacturer: Stellantis (Citroën / Peugeot)
• Model: Citroën C4; Citroën C4 II; Citroën C4 Picasso; Peugeot 3008 I; Peugeot 308; Peugeot 5008 I
• Product Codes: 9676592280; 9802043580; 6500KV
• Additional Numbers: 6500KR

Function And Role

The unit measures battery voltage, temperature and load conditions to determine the battery state of charge. It informs the alternator control and other vehicle control units to apply the correct charging strategy, preventing overcharging or deep discharging. Proper operation improves battery life, reduces fuel consumption in stop-start systems and protects sensitive electronics.

Common Failure Causes

• Corrosion and Moisture Ingress: Connector corrosion or water penetration leading to intermittent contacts or short circuits.
• Electrical Stress: Voltage spikes, poor battery condition or failing alternator causing overloads on the module.
• Thermal Stress And Ageing: Heat cycling and aging of electronic components over time.
• Mechanical Damage: Impact or improper handling during previous repairs.

Replacement Procedure

Replacement is straightforward for a competent mechanic with basic tools. General steps:

1. Disconnect The Battery: Always disconnect the negative terminal before starting to avoid short circuits and protect the unit.
2. Locate The Unit: The BSM is usually mounted in the engine bay or under protective covers near the battery/electrical distribution area—refer to vehicle repair manuals for exact position.
3. Disconnect Electrical Connectors: Carefully release locking tabs and unplug all connectors. Inspect connectors and harness for corrosion or damage.
4. Remove Fasteners And Extract Unit: Unscrew mounting bolts/clips and remove the module.
5. Fit Replacement Unit: Position new unit, secure fasteners and reconnect all connectors. Reconnect the battery last.

After replacement, perform basic checks: verify charging voltage at idle and during load, check for diagnostic fault codes and confirm proper communication with vehicle systems.

Service Life And Maintenance

There is no fixed mileage for failure; problems commonly appear on older or high-mileage vehicles and after exposure to moisture or electrical faults. Preventive actions include keeping battery terminals and connectors clean, ensuring a healthy battery and alternator, and protecting wiring from water ingress.

Notes For Buyers

This unit is commonly looked up by OEM part numbers 9676592280, 9802043580 and 6500KV. Make sure the part numbers match your vehicle’s requirement before purchasing. Suitable for professional garages and experienced home mechanics familiar with vehicle electrical systems.