Dual Battery Surprise

[tschwein]

I was surprised by unexpected electrical problems when battery #1 on my 2005 Four Winns Horizon 250 failed. With the battery selector in the #2 position, I could start the engine and continue underway, but there was no power to run the outboard trim motor nor the radio. I always thought that the two batteries gave me full redundancy in the event one failed, but apparently that's not the case.

I took the boat into the dealer and he replaced #1 battery and then everything worked correctly again, including outdrive trim and radio. The repair guy explained to me how the batteries are wired, but I'm still not sure I understand since it's still not making sense to me.

If I understand him correctly, he's saying that the electrical systems that operate in the boat are wired independently between battery #1 and battery #2. Thus if one of your two batteries goes dead, you lose power to some portion of your boat systems. That's apparently what happened to me when I lost power to the outdrive trim motor and radio when battery #1 failed. Restoration of trim motor and radio when battery #1 was replaced sure seems to confirm what he's telling me.

Has anyone else run into this and understand how the dual battery thing works? This is totally different than how I understood the dual battery switch setup works.

 

[special_kaye]

Re: Dual Battery Surprise

I was surprised by unexpected electrical problems when battery #1 on my 2005 Four Winns Horizon 250 failed. With the battery selector in the #2 position, I could start the engine and continue underway, but there was no power to run the outboard trim motor nor the radio. I always thought that the two batteries gave me full redundancy in the event one failed, but apparently that's not the case.

I took the boat into the dealer and he replaced #1 battery and then everything worked correctly again, including outdrive trim and radio. The repair guy explained to me how the batteries are wired, but I'm still not sure I understand since it's still not making sense to me.

If I understand him correctly, he's saying that the electrical systems that operate in the boat are wired independently between battery #1 and battery #2. Thus if one of your two batteries goes dead, you lose power to some portion of your boat systems. That's apparently what happened to me when I lost power to the outdrive trim motor and radio when battery #1 failed. Restoration of trim motor and radio when battery #1 was replaced sure seems to confirm what he's telling me.

Has anyone else run into this and understand how the dual battery thing works? This is totally different than how I understood the dual battery switch setup works.

Not sure how much this'll help but I was told, "put one battery to start your engine and run everything while underway. This'll be a marine starting battery. Then, use a marine deep cycle battery to run house electrics while at anchor." Whether that's right or not, I'm not sure but he sure made sense to me and it sounds good.