Winter disconnect for batteries in series

Yes, leave the series linking cable intacked. Many boats have critical loads thats are connected direct to the battery, like the auto bilge, anodes and CO detectors. On smaller/trailer boats, disabling the auto bilge can be a disaster over winter. Ever the the moldy interior when the owner pulls the winter cover off to find the boat has been filling with rain water? Or a wet-slipped boat goes down because of collected rain. Your choice to disconnect the critical loads. However, you are better off the just disconnect the main grounds off the banks. This leaves the seriesed batteries still connected as one large 24V battery.

 

Ah, but... SB is storing inside so since he'll have no need for those things, disconnecting is fine.

Trailer boats laid up for storage wouldn't need those things either since the drain plug should be removed for storage... and, really, removed every time the boat is pulled out.

SB... if your plan is to connect battery chargers every time you visit the boat then, if it was me, I would just leave all batteries connected and turn the battery switch off. When you visit, connect to shore power with an extension cord and 15a to 30a adapter (or 50a, depending on what you have) and let your onboard charger do the work.

 

I see where you're coming from, now. Understood.

There's a lot of variables in the boating world - and that's not even taking account the "previous owner" factor you were eluding to... which can sometimes be quite time consuming to fix!

Some boats (smaller ones, primarily) don't have battery switches so that starter lead would be hot. Although that's not the case here so that's more of a tangent and not directly related to this thread.

But for me, my brain is so wired (see what I did there?) to pull that negative cable off the battery first, I just can't convince myself to pull the positive first - in some boats, the batteries are actually quite close to the engine(s). I'm also in the boat business and have always done it that way (including the merc technicians here). But as discussed, this a different scenario than the sensitive electronics you were talking about. I just can't do it, captain!

I do appreciate the information you have passed along!

 

One thing to keep in mind, especially if your in the water with a boat plugged into the dock. The DC ground and the AC bonding are one in the same, or should be. They are supposed to be physically tied together. Removing the ground first could cause an issue an possibly get shocked (by AC current) in doing so. Just something to keep in mind and probably should always wear gloves removing the ground from a boat powered by shore power.

 

Something like this would do it. It wouldn't provide enough power to run all of your AC equipment, but should be more than adequate for the chargers and some lights. Although checking the power requirements of each charger would tell us for sure. This will power the boat just like you would from the pedestal at the dock, albeit with less amperage coming in.

https://www.marinco.com/en/p/150SPP/Pigtail-Adapter-15A-125V-Male-To-50A

But, absolutely - if you've got a system that works for you... then keep using it!

 

You don't have to be an EE to figure that out... you just shouldn't be a space cadet and totally space on that little fact like me

Now... you could... swap the breakers for the chargers to the other line and bring two same-sized breakers back over the first line... but I think the way you're currently doing it is "just fine"!