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Alternator Regulators
Multi-stage external regulators for 12V, 24V and 48V alternators charging lithium or lead-acid banks.
External Alternator Voltage Regulators for Smarter Charging
A standard internal regulator is built to top up a starter battery, not to charge a large house bank. An external alternator voltage regulator takes over field control and applies a programmable multi-stage charge profile. This lets your alternator charge deep-cycle lithium or lead-acid batteries more effectively while the engine runs. This collection covers 12V, 24V and 48V regulators from Balmar, Wakespeed and Mastervolt for marine, caravan, RV, 4WD, truck and off-grid systems.
Please note these are alternator regulators. They control engine-driven charging and are not solar charge regulators.
Balmar Multi-Stage Regulators
The Balmar range covers most system voltages. Each listed model includes a harness, and the dual-alternator model includes harnesses.
- Balmar ARS-5 (12V): a multi-stage regulator for single-alternator 12V systems.
- Balmar MC-618 (12V): a multi-stage regulator for 12V house bank charging.
- Balmar MC-612-DUAL (12V): controls two alternators on twin-engine boats or dual-alternator vehicles.
- Balmar MC-624 (24V): available in standard and clamshell packaging for 24V marine and truck systems.
- Balmar MC-620 (48V): suits 48V house banks in larger vessels and off-grid installs.
- Balmar Smart Ready Internal Regulator Kit (12V): made for Yanmar and Valeo alternators.
Wakespeed WS500 Pro and Mastervolt Alpha Pro III
The Wakespeed WS500 Pro Bluetooth Alternator Regulator is a highly configurable smart regulator. You can set it up over Bluetooth, which makes it a popular choice for lithium house banks where charge voltages and limits must be set correctly. For help choosing and setting one up, see the Wakespeed WS500 buyer's guide.
The Mastervolt 12V/24V Alpha Pro III Alternator Charge Regulator works with both 12V and 24V systems. It is a flexible option for fleets or mixed-voltage vessels.
Selection Tips: Matching a Regulator to Your Setup
Work through these points before you choose a regulator:
- System voltage: match the regulator to your battery bank. The ARS-5, MC-618 and WS500 Pro suit 12V systems. The MC-624 suits 24V, the MC-620 suits 48V, and the Alpha Pro III covers 12V and 24V.
- Number of alternators: twin-engine or dual-alternator setups suit the MC-612-DUAL.
- Battery chemistry: lithium banks need a correctly programmed profile. Prioritise models with detailed configuration, such as the WS500 Pro.
- Alternator capability: an external regulator only performs as well as the alternator it controls. Consider pairing it with one of our high output alternators for bigger charging loads.
- Sensing and wiring: temperature sensors, harnesses and protection modules help protect the alternator and batteries. You can find these in alternator regulator accessories.
Upgrade Your Engine Charging Today
Choose a regulator above that matches your voltage and alternator setup. You'll get faster, better-controlled charging every time the engine runs. If you're unsure which model suits your boat, RV or truck, contact our team before ordering.