Blue Sea 7622 - Winch Battery?

[Douglas S.]

Hey,

I'm midway through installing a Blue Sea 7622 in my 80-Series. 2/0 cable throughout, both batteries located in the engine bay.

Will it make any kind of material difference if I connect my winch to one battery or the other? My initial thought is that it would be best connected to the battery that is directly connected to the alternator, but when winching I will parallel the batteries so I'm not sure what the advantage would be. From a wiring standpoint it is easier for me to wire to the secondary battery, but I can make either one work.


Appreciate any advice.


Thanks,
Doug

 

[R Thomas]

The winch is normally connected to the secondary battery, to prevent discharging your start battery and stranding you.

 

[Douglas S.]

The winch is normally connected to the secondary battery, to prevent discharging your start battery and stranding you.

I'm having trouble coming up with a scenario that would result in the winch slowly drawing down the battery. It uses an Albright contactor and will soon be switched with a Blue Sea solenoid for extra safety.

That said, it's certainly something to think about. I know that with the IBS system they recommend that the winch be wired to the starting battery, but that's because the solenoid they use can't handle winch current being pulled through it.

 

[1stDeuce]

IF you plan to winch without the engine running, and disconnect the batteries to do so, and you winch a LOT after disconnecting, then what R Thomas said is the way to go.

On it's own, a winch won't run the battery down unless it gets engaged somehow, and then running the battery down isn't the big worry, it's the fire that results pretty quickly thereafter...

Ideally, connecting to the battery that gets the alternator feed would provide the best voltage, but with 2/0 cable connecting the two, (would have been better with 1/0, but 2/0 is ok...) there's not a huge difference, and the winch pulls so much more than the alternator that both batteries will drag down anyway, and if you're winching hard, the ~80A that the alternator makes at or near idle is a small part of the amperage supply.

The disconnect amperage rating could be a concern, but if your disconnect can handle ~500A, then you should be fine hooking to the secondary battery. The difference in amperage flowing through the disconnect between hooking to the main and the secondary battery is only what the alternator puts out. I think your disconnect is rated pretty high IIRC...

So... I say hook it to the one that makes for the cleanest install.

<edit> One more thing to consider is that you want the cable from the battery to the winch as short as possible for minimal voltage drop. Use 2/0 or 1/0 and make good end connections and your winch will work much better than if you use the factory supplied #4 cables with crappy crushed tin ends. The shorter the cables are, the less voltage drop, and the happier your winch will be.

 

[Douglas S.]

IF you plan to winch without the engine running, and disconnect the batteries to do so, and you winch a LOT after disconnecting, then what R Thomas said is the way to go.

On it's own, a winch won't run the battery down unless it gets engaged somehow, and then running the battery down isn't the big worry, it's the fire that results pretty quickly thereafter...

Ideally, connecting to the battery that gets the alternator feed would provide the best voltage, but with 2/0 cable connecting the two, (would have been better with 1/0, but 2/0 is ok...) there's not a huge difference, and the winch pulls so much more than the alternator that both batteries will drag down anyway, and if you're winching hard, the ~80A that the alternator makes at or near idle is a small part of the amperage supply.

The disconnect amperage rating could be a concern, but if your disconnect can handle ~500A, then you should be fine hooking to the secondary battery. The difference in amperage flowing through the disconnect between hooking to the main and the secondary battery is only what the alternator puts out. I think your disconnect is rated pretty high IIRC...

So... I say hook it to the one that makes for the cleanest install.

<edit> One more thing to consider is that you want the cable from the battery to the winch as short as possible for minimal voltage drop. Use 2/0 or 1/0 and make good end connections and your winch will work much better than if you use the factory supplied #4 cables with crappy crushed tin ends. The shorter the cables are, the less voltage drop, and the happier your winch will be.

Thanks, I appreciate the detailed response.

I think I'll just wire up everything but the winch and see what will work best for me at that point. The cable runs to the winch are 1/0; 8274 is a bit of a current hog.