Musing on DC Electrical Changes

Apr 22, 2025
13
Morgan 321 Oswego
Thanks all for your replies and suggestions. You've given me a lot to ponder.

Interesting and lots of suggestions here, yet the first and most basic question has not been asked of the OP, what's the intended use of the boat? The answer to that question is even more fundamental than then load analysis.

So, TrapperJohn, how do you intend to use your boat?
I guess I left that out in my initial post. Wasn't looking at it that way.

Now that you mention it, this first year, my intention was to just be daysailing in different weather conditions to get a feel how the boat handles and to "get away" for a day on the water. I was hoping the current batteries would make it through this year but if not, I'll just buy a couple cheap LA batteries to get me by. Of course, if I don't get it in the water soon, maybe it will end up a flower planter in the marina. :banghead:

Next year, it would be the start of more extensive traveling on the Great Lakes and maybe part of the seaway. That's where the upgrades hopefully would be starting also and is still doable with marina-hopping. The goal is to be able to do an overnight sail to Canada to visit our neighbors to the north and minimize motoring to get there.

Longer term would be a trip to the Carib for a few months if this old body holds up. This was where I was finally planning the lithium upgrades. Who knows, maybe by then it will be in a newer boat anyway.

Nice boat! I like that model very much! What engine do you have? Yanmar GM2?? or 3??.
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I've been upgrading my entire system before converting to lithium batteries so that when I need to replace my batteries, it should be relatively pain-free. I'm still running strong with 2 AGM batts (4D) with 400 ah capacity since 2015. However, if and when I get to do more intensive cruising, I'm ready to drop in lithium for greater capacity and less weight! With shore power, my batts are perpetually topped off and a few nights on anchor between charges is stress free.
Scott, I have a Yanmar 3GMF with 1000 hours on it.

Your last paragraph was similar to my thinking about the progression also. Everyone else has also chipped in with helpful suggestions.

The reason I brought up the cable replacement and going to a yellow ground (-) was two-fold. 1.) I don't have much slack with what's there and if I need to move cables around and re-terminate, it may be a stretch, and 2.) when I was pricing out cabling, I found that Home Depot (that I mentioned earlier) had 2/0 cable on 25 ft spools cheaper than buying 1/0 bulk cable anywhere else for the same quantity. They only have red & yellow. I can live with red/black but what the heck.

Thanks again everyone. If you have other thoughts, I'd be glad to hear them.