STINGER dual battery isolator SGP32 12V 200A continuous 500A surge — relay-based, water-resistant

The STINGER SGP32 is a 12V, high-current dual battery isolator and relay that safely separates a vehicle’s start battery from a secondary battery while allowing up to 200A continuous charging and 500A surge transfer.

Designed for cars, trucks, marine craft and off-road rigs, this compact isolator combines a heavy-duty relay with a robust isolation mechanism to keep your main battery reserved for engine starts while powering accessories from a secondary battery. Built with water-resistant phenolic plastic and engineered for long life, the SGP32 fits into installations where dependable high-current switching and corrosion resistance matter.

How does the SGP32 protect my primary battery?

The isolator prevents accessory loads from draining the vehicle’s starting battery by routing alternator charge to a separate secondary battery while keeping the two batteries electrically separated when the engine is off. As a relay-based system, it automatically connects for charging and disconnects to protect starting capacity.

• Automatic relay engagement when alternator voltage is present
• Prevents accessory draw from draining the starter battery
• Supports a dedicated house or audio battery for accessories
• Reduces risk of being stranded due to accessory drain

What electrical capacity and durability does it offer?

The SGP32 is rated for continuous currents up to 200 amps with the ability to handle 500-amp surge currents, making it suitable for high-power audio systems and demanding accessory loads. Its mechanical components are specified for a long operating life to withstand frequent charge cycles.

• 200A continuous current handling for heavy loads
• Up to 500A surge capacity to accommodate startup spikes
• 100,000 mechanical cycle life for reliable repeated switching
• Phenolic housing resists moisture and environmental wear

Is the SGP32 compatible with my vehicle and charging system?

This isolator is universally compatible with 12V charging systems and works with standard alternators, smart charging systems, and most vehicle electrical setups. Its straightforward wiring and robust terminals simplify installation into cars, boats, ATVs, or trucks without special alternator modifications.

• Works with any 12V alternator or charging configuration
• Suitable for automotive, marine, and powersports applications
• Compact footprint fits common mounting locations
• Water-resistant construction for damp environments

How do I use the SGP32 with an audio or accessory battery?

Connect the isolate relay between the vehicle’s charging output and the secondary battery; the relay will close to charge both batteries when the engine runs and open when the engine stops, isolating the main battery. This setup lets you run stereos, winches, refrigerators, or lighting from the secondary battery while preserving starting power.

• Install on the alternator output or battery feed line
• Wire secondary battery to accessory loads and audio systems
• Ensure secure terminal connections and proper fuse protection
• Mount away from excessive heat and in a protected, ventilated spot

Who this product is for: The STINGER SGP32 is aimed at drivers and installers who need a heavy-duty, reliable way to manage dual-battery systems—car audio enthusiasts, overland and off-road vehicle owners, marine boaters, and anyone adding high-draw accessories. If you want to protect your starter battery while supplying consistent charge and high-current capability to a secondary battery in wet or rough environments, this isolator gives a rugged, long-lasting solution without complex electronics.