Monthly Archives: January 2019

Quick follow up on battery protect boards

Posted on by
7

Anton asked this morning if those little boards are at risk from overcooking. Each one is rated to handle just under 2 amps. We doubled them up on each cell, figuring about 3.5 amps working capacity. The 400 watt solar array, converting through the Victron MPPT controller, is pumping at maximum about 6 amps total to the batteries. So with 4×3.5=14 amps of resistance capacity, I think we’ll be fine. Jeff said that in practice on his big cat in the tropics, yes the boards got warm when they kicked in, but never hot. We mounted them with double sided tape, which gives an air cushion under most of each board, and the whole cabinet is a good heat dissipation sink. Hopefully we’ve solved for Anton’s warnings.

Locals, let me know if you want to sail the boat next week. Throw some dates out and we’ll make some plans.

Future Crew

Posted on by
2

Say hello, sailing world, to Westley. Born perfectly yesterday, 10lbs, giving our sis / his Mom a run for her money. His Dad Joe is a sailing captain, mom owns a Santa Cruz 50, Aunt & Uncle with Ravenswing; well let’s just say he has some sea miles ahead of him.

Westley doesn’t need it yet, but the rest of the crew wants the toilet back. Work proceeds.

Second coat of paint went down today, and all the new hose routings were cut to fit. One more paint coat and the plumbing reinstall this weekend will put the head back in business.

Highly-credentialed multi-huller Jeff visited with his soldering iron during a road trip this week. He donated these resistor boards to the lithium battery cause, and did expert wire connections. what you’re looking at (the green circuit boards mounted above the batteries) are charge balancing modules to regulate the pace at which the four “cells” of this battery bank rise in charge voltage. The risk in an LiFePO4 bank is the cells getting out of voltage balance from their neighbors, and potentially ruining sections with out-of-range values. With these little control boards, when one cell reaches 3.6volts (its full charge), the incoming voltage is converted to heat in those blue resistors. That cell is effectively bypassed from further charging while the others catch up. That’s as simple as I can say it, but there’s more going on with the numbers. It’s a crude version of a Battery Management System, and we’re judging it sufficient for our solar-only gentle charging regimen. Coming up soon we’ll install the CellLog that monitors and alarms each of the four cell voltages that get out of range. That will complete our safety installation.

We found some time to get back to the navigation system. Today was the first time to fire up the radar dome since purchasing it from a San Juan Islands f-31 about five years ago. Anxious moments when we hit the power button on the chart plotter…

And with zero operating knowledge or adjustments, up came…YESSSSSS! As soon as the autopilot install is done, we’ll get out and test/tweak/learn all this gear.

Final carbon work on the autopilot mount:it’s bonded together now, faired and primed. Paint coat tomorrow if this rain departs for points east.

Last Sunday Dad and I were on the Bayshore freeway and I thought I spotted a huge mast. On the way home, we exited towards the Oracle campus, on the hunt for Dogzilla. Visitors to our Santa Rosa build shop might remember I had this boat’s photo on the door for inspiration those years.

We all know what it took to build our new 54′ mast. This one is 223′, got used for one regatta, and now serves as a statue. Now that’s rich-guy extravagance.

Be a better blogger

Posted on by
3

I know, I know, you subscribed to this thing and you expect frequent Ravenswing updates. Well the Carters wish you a happy 2019, belatedly.

We left off two months ago showing a box of Pelagic Autopilot parts. Installation is now underway. The drive unit has to hang out in space, given our cassette-style rudder. Here’s mocking up the placement…

That’s going to need a stiff arm, 16″ tall off the swim-step deck. There was about 2′ leftover from that old Craigslist-find windsurfer mast that is now the pickup’s SUP rack. the base bracket is an offcut scrap from the first (didn’t like the feel) steering iteration. Repurposing these quality carbon pieces saved a bunch of time, and was free! The bracket will mount in these four holes, and the power cable gets an outlet plug in the transom.

The controller easily went in to the companionway dashboard, and the brain box will be bulkhead mounted in the equipment room once we buy a bit more wire. We should be testing this unit in just a few more boat work days.

In November we started thinking about everything that needs to be trialed / pushed hard here in the bay before 2019 ocean voyages. A big nagging item has been filling the toilet holding tank to capacity and testing the at-sea emptying. Well let’s just say that we never got to the “take it out 3 miles and pull the plug” part. In retrospect, I should NOT have chosen a complicated shape, under floor sewage keeper as my first-ever composite tank build. The idea was it would drain like a water ballast tank on powerboats (or our old Macgregor 26x). Get up above 8kts and suction will empty the tank. So we pumped 15 gallons through the toilet, filled the tank, and things didn’t smell so good. A bit of sewage was now outside the tank, under the bolted-in bathroom floor. Uh-oh. That hideous photo is after hand pumping three buckets and trudging them up to the Marina toilet, then ripping out the tank that we had spent days building a few years ago. GROSS! (If you really want to see the old tank, search on the Plumbing link at the home page, back in late 2015 I think)

Once cleaned up, it’s time to lower down, then bond in, the previously bolted (removable) sole. Upper level is the toilet deck. The old tank had used all the non-white space here as it’s form.

Yes those are inspection hatches in the sole; the sea drain for the new tank runs under this floor and the shower, over to a proper 1.5″ seacock.

The new tank will be bulkhead mount, behind the toilet. It sits way above the waterline, so this should be a foolproof simple gravity drain. Also the dock-based pump out will be only a 3′ lift, which is light duty for most Marina pumpout stations. And yes, I forked over $200 for a factory built Ronco plastic tank with our specific fittings pre-installed. It will sit on this little shelf, made yesterday to bolt to the bulkhead at the forward end of the head compartment (bathroom).

I probably deserve all your poop jokes at this point, but just remember, my mother still reads these comments.

A week after throwing our old tank in to this dumpster, somebody else apparently got even more pissed off than me…I doubt it will plane.