Charging Systems

Is the battery warning light coming on while you drive, or does your battery need to stay fresh through a long winter break? This category brings together parts for the charging system: alternators, stators, voltage regulators, battery chargers and accessories. It is for you if you want to troubleshoot, replace worn parts or maintain the battery in your car, motorcycle or other vehicle.

How the charging system parts work together

The charging system keeps the battery charged while the engine is running. Most cars have an alternator with a built-in or separate regulator, while many motorcycles and powersports vehicles use a stator that supplies alternating current to a regulator/rectifier. The voltage regulator keeps the voltage within a specific range so the battery is neither undercharged nor overcharged. Arrowhead, for example, is represented with regulators/rectifiers in the category. Measure the charging voltage with the engine running before you replace parts – a faulty regulator and a weak stator can cause similar symptoms.

How to choose a battery charger

First and foremost, the charger must match the battery's voltage and type. Lead-acid, AGM and lithium require different charging profiles, and a lithium battery should only be charged with a charger or mode designed for it. The charging current should match the battery's capacity: a low current, e.g. 0.8 or 2.3 A, is typically suitable for smaller batteries and maintenance, while larger batteries charge faster with e.g. 7 or 10 A. Also consider whether the charger needs to handle maintenance charging over longer periods, and whether it will be kept in a cold or damp garage. Among our battery chargers you will find models from CTEK, Battery Tender and Antigravity, for example.

Accessories and installation

Charging cables, connectors and wall brackets make it easier to connect the charger and store it safely. A permanently mounted charging connector on the vehicle can save you from removing seats or panels every time. See our charging accessories, and check that the connector type fits your charger, as systems are not necessarily compatible across brands. If you replace the alternator or regulator, the connectors, output and mounting points must match the vehicle, and the wiring harness should be checked for corrosion and poor connections.

Frequently asked questions

How do I know whether it is the alternator or the battery that is failing?

Measure the voltage across the battery with the engine off and then running. If the voltage does not rise when the engine is running, this typically points to the alternator, stator or regulator. A battery that does not hold its charge after a full charge may itself be worn out.

Can I charge a lithium battery with a regular charger?

It depends on the charger. Lithium batteries typically require a different charging profile than lead-acid and AGM, and some standard modes can damage them. Use a charger or mode specified for lithium, and follow the battery manufacturer's instructions.

Why does the regulator fail again after replacement?

Repeated failures can be caused by poor connections, corroded connectors, heat or a faulty stator that puts strain on the regulator. Check the wiring and ground connection, and measure the stator's output before fitting a new regulator.