2000 MS battery update

My four 8D batteries no longer were providing much amp hours, even after a full charge.

So with all this time being Locked Down courtesy of Covid 19, I decided to address this issue. Did alot of research on various battery options, and came to the conclusion of "what aint broke, don't reinvent".

Decided to install four new 12v 8D batteries again each with CCA 1425/CA 1750, as they serviced the PO for 10+ years, and gave me another two with my ownership. When replacing the starboard side batteries, I discovered the battery tray was rotting away after 20+ years.

I searched online for a week, for a 8D plastic battery tray, but to no avail. Then decided to build my own, and make it from 3/4" thick star board, with through bolts for added strength. I ordered the pieces I needed precut from Boat OutFitters https://www.boatoutfitters.com/material/plastic-sheet/king-starboard, and as usual they did not disappoint in very quick cutting and shipping time frame (like 48 hrs!).

Assembled the support and battery tray combo today, and installed it. So another check mark on the honey do list of boat projects.

Looks nice. Did you make the tray leak proof? How?

Think I'd have avoided 8Ds, instead used some group of smaller individual batteries to make up the same or more capacity... but that's mostly 'cause I don't want to be lifting 8Ds ever again.

-Chris

Nice work. Looks like the 8D’s are easily accessible so why not? If it ain’t broke.....

I used the large 8D's to minimize connections which could corrode. Yes, they were heavy and cumbersome to handle, but you only do it once. They are set up as 2 8D for port side and 2 8D starboard side house/starting, with a switch to isolate/combine. Now plenty of amps to operate my Cat starter, windlass, and bow thruster. I sealed the tray with a acid proof solvent. I have a separate generator battery as well, as a back up if these fail. Once the genset is started, the 40w battery charger could get the house bank charged.


All these are trickle charged by my 250w solar panel with smart controller.

suntansailor said:

I sealed the tray with a acid proof solvent.

Click to expand...

Thanks. Solvent? Or epoxy? Or...?

-Chris

I called it solvent, but used an epoxy to seal the joints. Used s/s through bolts for added strength.

Your 8Ds are all start batteries, not deep cycle batts? I prefer deep cycle, AH-rated batteries for my house bank. If it says CCA, my understanding is that it's a start battery, not deep cycle.

suntansailor said:

I called it solvent, but used an epoxy to seal the joints. Used s/s through bolts for added strength.

Click to expand...

Got it, thanks again.

-Chris

Well, you do whatever floats your boat of course. But you may want to read my article in the Library/Misc section (upper right icon on this screen) for future reference.

But by then LiFePO4 batteries will be half the cost of today's batteries and probably the preferred choice for house use.

David

Installing 8D's

I replaced the two 8Ds on Mainia about a month ago. I went with gels for reasons not important here.



To get them in the bilge we used two saw horses and some wood to span the floor opening, and a cross beam rigged with a four part block and tackle to lower them down. I had everything on hand so to was easy. Much more practical and safer then trying to manhandle them in like we did eight years ago.


Jamie