An automatic charging relay (ACR) helps two battery banks share an available charging source without leaving them permanently connected. Blue Sea 7601 and 7610 do this job at different current ratings, with different terminal hardware. This guide identifies the two relays, shows their normal operating states and links directly to the exact NewRVParts listings.
How the relay links two battery banks
The two battery positives are connected to their own appropriately fused ACR studs; the relay closes only when operating conditions call for combining. The relay also requires its specified ground and any start-isolation wiring. The drawing below shows the relationship, not cable routing or terminal positions.
The ACR can close between battery positives after suitable charging voltage is detected, allowing both banks access to the charge source.
When the voltage decreases to the specified disconnect threshold, the relay opens so the banks are separated.
With the start-isolation input wired as directed, engine cranking temporarily opens the relay to help protect house electronics.
7601 versus 7610: exact model specifications
| Model detail | Blue Sea 7601 | Blue Sea 7610 |
|---|---|---|
| Type | 7601 mini automatic charging relay (m-ACR) | 7610 start-isolation automatic charging relay (SI-ACR) |
| Battery systems | 12V DC / 24V DC | 12V DC / 24V DC |
| Continuous relay rating | 65A | 120A |
| 5-minute intermittent rating | 115A | 210A |
| Main battery studs | 1/4 in–20 (M6) | 3/8 in–16 (M10) |
| Main stud material | Tinned brass | Tinned copper |
| Stud tightening torque | 60 in-lb (6.78 Nm) | 140 in-lb (15.82 Nm) |
| Start isolation input | Yes, when correctly wired | Yes, when correctly wired |
| Factory kit association | 7649 mini Add-A-Battery | 7650 / 7650003 Add-A-Battery |
For an RV auxiliary-battery installation, current rating is only one part of the choice. Look at the installed alternator or charger, the battery chemistry, cable and overcurrent protection requirements, and the location of the existing relay. A 7610 is not automatically a drop-in replacement for a 7601.
Matching relays in the NewRVParts catalog
Each product card uses the photograph from its own NewRVParts listing. Open the product for current warehouse availability and ordering; these items ship from supplier warehouses and are not offered for onsite pickup.
Manufacturer installation diagrams and specifications
Blue Sea publishes connection, mounting and troubleshooting documents on its 7601 mini ACR page and 7610 SI-ACR page. The original side-by-side specifications show the terminal differences. Use the current installation sheet for the exact relay revision to determine protective fuse sizing, terminal locations, start-isolation control, and polarity.