Blue Sea Systems SI-Series Automatic Charging Relay, 120A, 12V/24V, IP67, Ignition Protected
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Overview
The Blue Sea Systems 7610 is a 120A SI-Series automatic charging relay with start isolation for 12V and 24V DC battery systems. It combines two battery banks when charging voltage is present and separates them when charging stops, so a start battery and a house bank can share charging without remaining linked under discharge. Auto-ranging input, dual sensing, and an IP67-rated housing make it a practical fit for boats that deal with spray, vibration, and mixed charging layouts.
On board, its main job is to keep charging automatic while reducing the voltage sag and spike issues that can reach house electronics during engine cranking. Start isolation opens the relay during crank events, and under-voltage lockout prevents it from closing below 9.5V on 12V systems or 19V on 24V systems. The relay is ignition protected for gasoline-powered boats and is rated for 120A continuous service, with a 210A intermittent rating for 5 minutes.
Key features
- 12V and 24V auto-ranging operation for boats with either system voltage
- 120A continuous rating and 210A intermittent rating for 5 minutes
- Dual sensing responds to charging voltage on either battery bank
- Start isolation opens the relay during engine cranking to keep house loads off the start circuit
- IP67-rated housing with hermetically sealed contacts for wet marine spaces
- Ignition protected for installation on gasoline-powered boats
- Built-in LED shows combined status, and quick-connect terminals support ground, SI, and an optional remote indicator lamp
- 3/8 in - 16 tinned copper studs with 7/8 in stud length for battery cable lugs
Installation and fit
This relay fits boats with separate start and house banks that are charged by an alternator, an onboard charger, or another DC charging source. Because it senses charging on either bank, it works in layouts where the charge source lands on the engine battery on one boat and the house side on another. It is a strong match for cruising boats, fishing boats, and sailboats that want automatic battery charging without needing to manage the banks by hand every time the engine starts or a charger comes online.
The 7610 should be used as a charging relay, not as a path for starter motor current. If your system needs an emergency parallel function for cranking, that should be handled by a switch or combining setup rated for starting loads. When planning the install, the main checks are cable lug fit on the 3/8 in studs, fuse protection for the connected cables, and enough mounting clearance for the relay body and cover. It can live in places that see washdown or splash, though a dry protected mounting location is still the better choice when space allows.
Shipping
We ship worldwide from the United States. Rates are calculated at checkout based on destination and package weight. Some items include free shipping, which will show automatically. Not every product is eligible for international shipping; checkout will confirm eligibility. We do not ship to PO Boxes except through USPS, and not all packages qualify.
Processing and dispatch
Most orders are verified, packed, and handed to the carrier within 1 to 2 business days. Some products may need extra handling time or ship directly from the manufacturer. For certain international orders, inventory transfers between warehouses may add time. If any delay is expected, we will let you know the dispatch date.
Delivery and tracking
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Duties, taxes, and support
International customers are responsible for any customs duties, taxes, and fees charged by the destination country. If these charges are refused and a shipment returns to us, the carrier’s return cost and any re-entry customs fees will be deducted from the refund. If your order is late or you need help, contact cs@qualityboatparts.com and we will assist you.
Quality Boat Parts is a reseller. Many items include a manufacturer’s warranty, and all warranty service is handled directly by the manufacturer. We do not manage or administer warranty claims on behalf of customers.
Warranty terms, coverage, and duration are set by each manufacturer. Issues involving defects, repairs, or replacements must be addressed with the manufacturer’s support team. When available, the warranty period is listed on the product page. If it is not shown, contact us or the manufacturer for details before purchasing.
To start a claim, the customer must contact the manufacturer and follow their process. Keep your proof of purchase and original packaging, and register the product if the manufacturer requires it, as these are often needed for warranty service.
We are happy to help you find the right contact or documentation, but we cannot decide outcomes or intervene in claim resolutions. For guidance, email cs@qualityboatparts.com.