Yamaha Battery Isolator - Dual Charge Monitoring System

[Deadrise36]

Consider “house batteries” to power accessories. Most large Yamaha outboards (150hp and up) have separate battery isolator/charging leads specifically for this purpose. The outboard’s Dual Charge Monitoring System, with proper wiring, will first send charging voltage from the stator to the starting battery/batteries to help keep the voltage up and ready to go. Once fully charged, the outboard will automatically “switch” the charge to the house battery/batteries.

Boat (2020 2520 w/300hp) is in storage, do they come wired this way from the factory?

 

[warthog5]

Yes they do, as well as other Outboards.....I'm tell'en you......Just install a BEP Cluster and you will have better control and be ahead of the game.

 

[pelagic2530]

Yes they do, as well as other Outboards.....I'm tell'en you......Just install a BEP Cluster and you will have better control and be ahead of the game.

Wart, just so I'm clear. With a twin F150 setup and a BEP twin engine/three battery bank switch, the only leads from the engine will be the positive wires to the output terminals of the BEP switch, and the negatives to the common ground busbar. The aux charging leads would be disused/removed. Is that correct?

 

[Deadrise36]

Thank you for taking the time to reply Warthog.

 

[warthog5]

Yes That is correct Pelagic.

There are a few thing to do to the BEP before it's installed.
They come with the 10ga wires on the back using Automotive connectors.
Redo those wires using Crimp Shrinks.... Just use the original wires as a measuring tool.

Then look at the Relays..... You will see a small Black wire.....That goes to GND.

You will also see a Red wire that makes a loop..... Cut the Red wire end the is closest to the Black wire...clip it as close as you can were it comes out of the potted material on the back of the relay. .Install a Red Crimp/Shrink 3/8in eyelet on that wire....It will hook to the terminal on Start switch that the engine POS cable hooks to.

What that does is kill power to the Relay when the Start switches are OFF.

 

[pelagic2530]

Tan

Yes That is correct Pelagic.

There are a few thing to do to the BEP before it's installed.
They come with the 10ga wires on the back using Automotive connectors.
Redo those wires using Crimp Shrinks.... Just use the original wires as a measuring tool.

Then look at the Relays..... You will see a small Black wire.....That goes to GND.

You will also see a Red wire that makes a loop..... Cut the Red wire end the is closest to the Black wire...clip it as close as you can were it comes out of the potted material on the back of the relay. .Install a Red Crimp/Shrink 3/8in eyelet on that wire....It will hook to the terminal on Start switch that the engine POS cable hooks to.

What that does is kill power to the Relay when the Start switches are OFF.

Thanks Wart. The BEP cluster for my 2530 project showed up yesterday, this will be my second one after the 1700 which has been working great. The automotive wire will be getting swapped out as soon as the rest of my wiring order comes in.

For anyone mulling over the project, the wiring that WartHog describes with the small red and black wires is complicated to write up, but very easy to do with the instructions they include in the package. For some reason, those same instructions are not available online, but it's very simple once you have the unit in hand and have the instruction pamphlet.