Shindig Volt Meter

This blog post will attempt to describe an instrument that I designed to monitor batteries on board.  Beware.... there is a lot of geek speak below.

One of the big challenges on Shindig is managing and monitoring all 13 batteries on board.  My DC system consists of 4 battery banks:

1. Domestic Bank - 8x 6 volt AGM
2. Engine Start Bank - 2x 12 volt AGM
3. Bow Thruster Bank - 2x 12 volt AGM
4. Generator Start - 1x 12 volt AGM

There is one Xantrex Amp/hour meter(Link 2000) that indicates battery health for the domestic and engine start banks.  While this meter is great for monitoring the amps in and amps out it doesn't tell me anything about the health of the individual batteries that make up the 24 volt banks.   Shindig only has one big bank (domestic) for operating all the onboard electronics, refrigeration, etc.  It is important that I keep a close eye on the health of this bank.

The purpose of the Shindig Volt Meter is to monitor the individual batteries that make up the system so that I can get an early warning if one is failing.  This will give me a chance to address the problem before a bank gets out of balance and impacts otherwise healthy neighboring batteries in the bank.

The meter is now installed and has already helped me identify a few batteries that were not pulling their weight.

The "Shindig Volt Meter" is based around the Arduino micro controller platform.  The Arduino is a popular hobbyist package that I started playing around with a few years ago.  It uses an Atmel micro controller that has all the digital and Analog to Digital (A/D) IO pins needed to do the job.

The input circuit multiplexes battery voltages through a resister ladder to voltage levels that the micro controler is happy with.  The Arduino controls a multiplexor to select the specific battery voltage to be read and then converts the analog voltage input to a digital value.  Once all the voltages are sampled they are compared to warning and alarm presets and output to the LCD.  The LCD is updated every half second as are the status lights.

Bread boarding the components for proof of concept

Placement of Arduino, voltage regulator, chip sockets and edge connectors

Back side of main board with LCD mounted

Final version installed on the boat.  This is showing the summary info screen for all 4 battery banks.

The red button allows you to scroll through different screens of information.

The two toggle switches are for on/off and LCD back-lighting.

The Green light indicates and all is well.

The Yellow light indicates that 1 or more of the 13 batteries voltage is below normal.

The Red light indicates that 1 or more of the 13 batteries is critical.

The alarm buzzer will sound if any one battery is in the red for more than 120 seconds.  It is common for batteries to bounce into the red under high loads(bow thruster, big inverter load, etc).  This is why I wait for 2 minutes before alarming.

Summary screen

Domestic bank details.  Port and Starboard 6 volts X 8

Engine bank detail.  2 X 12 volt

Thruster bank detail.  2 X 12 volt

Generator start battery.  12 Volt

Firmware version, threshold settings and "on" timer

Fuel System Upgrade

It is said that three most common issues with a diesel engine are:

1. Fuel
2. Fuel
3. Fuel

Shindig's fuel filtering system was pretty simple before I redesigned it.  There was one Racor filter/water separator for the main engine and separate one for the generator.  These filters were located close to the fuel tank under the main salon floor.

In rethinking the fuel system design I wanted to accomplish the following:

For the main engine fuel:

• allow for active and standby filter for the main engine so you can switch filters on the fly
• be able to service the filters easily
• read vacuum and pressure on the filters for diagnostics
• provide electric fuel pump backup to the main engine lift pump

For the generator fuel system:

• provide primary and secondary fuel filtration for the generator as the generator does not have a secondary filter.
• be able to service the filters easily
• provide electric fuel pump backup to the generator's fuel pump
• fuel polishing capability

This is what I came up with.

Main engine primary/standby filter configuration

For the engine system I moved the single filter from under the salon floor and plumbed it a second filter on a bulkhead in the engine room.  I have great access to the system in the new spot.

The valve between the filters selects the primary or secondary filter and the valve on the top right allows you to select the fuel pump for bleeding the system, servicing filters or act as a backup to the Perkins fuel lift pump.

The compound gauge on top of the primary filter reads vacuum (indication of how dirty filter is) and pressure for when the fuel pump is pressurizing the system (max of about 8 psi)

Generator filters and fuel polishing configuration

The generator system occupies the space under the salon floor where both systems were before. 

I have retained the capability to shut off the feed to either system at the tank (red valves) and tried to leave enough space under the floor to service the two generator filters.

I tested the flow rate for fuel polishing with this circuit and it measures about 24 gallons/hour.  The fuel pump consumes about 3 amps. 

The most challenging part of this project was finding a good spot for each system and locating the oddball Racor and other brass fittings.  I ended up getting the special Racor fittings online here.   The other fittings I found at Grainger and local hardware stores.

Boat Barter

As we get closer to our departure date Nancy and I are downsizing as much as possible and storing as little as possible.

This downsizing includes our cars.   If we are very successful and sell them quickly we'll have to rent or borrow a ride to finish our move out of the house and onto the boat.  If we are unsuccessful we'll have to store them or sink them in the bay! 

We have advertised them on Craigslist and Auto Trader and I have been driving the Mini around with a "for sale" sign in the rear window.

This week I received this note under the windshield wiper.

This deal wouldn't help on the downsizing!

We have received lots of inquires on the cars.  Many are scams and some are qualified buyers.
I find the craigslist/autotrader route is kinda a pain in the ass.  (flaky people, low ballers, email and phone followups the go nowhere).  I'll be happy when the deals are done and sad to see my little Cooper go......

Good Bye "INBOX"

42 days and counting.

2012 Master Mariners

Rob Posting....

I'm very late at writing the post.  In May I had the honor of driving Bounty around the San Francisco race course for the annual Master Mariners Regatta.

Bounty is a beautiful 52 foot Sparkman and Stephens that was launched in 1950.

Every stitch of sail up!  Notice the fire boat blasting water in the air in the background.  This was part of the destroyer Iowa's escort out of the bay.

This downwind leg was incredible.  Winds were in the mid-20s and Bounty was moving a lot of water!

This photo and the two above are compliments of Tom Zinn Photography

The mighty 11 Meter Pursuit as she passes us down the city front

Heading down the Oakland estuary after the race

Fantastic crew!

Encinal Yacht Club did a wonderful job getting all these wooden beauties crammed into the harbor

T-minus 2 months

From Nancy:

Having a great summer as we watch the calendar days march towards Sept. 15^th.  Aside from a few remaining boat projects that will require a few days being unavailable to play, Rob reports we really are ready to go.  Now we are also in social mode, getting in as much facetime with our land-based friends. 

Home has become two places, Los Altos and Sausalito, and we are back and forth each week, with our comical ‘family calendar’ which is NOTbased on Google or Outlook, but the basic 365 days at a glance in the home office.  

Bryan has settled into a great full-time summer job at Cisco, which keeps him busy, and me closer to Los Altos during his work week.  Last weekend was a flurry of phone calls, emails and texts, as several bigger household items were posted on Craigslist and Autotrader.  We sold our beautiful pool table and ping pong set to a couple in Modesto, parted with the rocketbox to a younger family that still camps and skis, and entertained lots of questions on our cars.  It was much easier to give away some bikes and other furniture to friends!  There are 55-60 neatly stacked and labeled boxes in our house, which are good reminders of all the things we really don’t need, but want to keep. 

The most common questions we get are “How long are you going to be gone” and “where are you going?”.  My response is based on practical things like, “well, we’re renting out our house a year at a time, but will be flying back for visits at least next spring and a longer stay in the summer”. (Note: America’s Cup 2013!). The “where are you going?” is easy, as Mexico seems like a fine destination with way too much to enjoy in one sailing season.  I describe Bryan’s finals schedule in December and his airplane ticket already purchased from Boston to Manzanillo. We know we need to be there December 16th. (Barra de Navidad)

The list is much smaller but here are some more notables on our calendar:

• Swing dance lessons – this week
• First aid/cpr class – next week
• Consult with our doctor friend on medical emergencies and needed prescriptions – this week
• Piano recital - (why not have more stress on my calendar?) –Thursday!
• Physicals, lab work, eye exams -scheduled
• Custom work out routine for sailing life  – I met a great trainer at the club who went cruising for a year in Mexico
• Get house ready to rent – starts showing end of July
• Sell two cars – in process 
• Enjoy 10 days in the Delta with sailing friends in August – Yippee!!!!

Shindigs

We've received feedback that the blog is a bit too technical "and boring".  Guarantee there will be a better balance once we actually leave on our adventure!  In the meantime, we're having Lots of fun with friends as we get ready for our travel south.  Here are some photos of recent sailing Shindigs.  Enjoy! - Nancy

Cockpit party in Sausalito

Women in Sailing seminar with Captain Rob

Yacht Club cruise in to Tiburon

Capt. Mark, Rob and the ladies

Rob skippering Bounty in Master Mariner's Race

Got Amps

Shindig carries 13 batteries on board and 8 of them make up the 24 volt house or "domestic" bank.
I had been noticing that this bank was not holding up well during weekend trips and that two batteries in particular were always 0.3 to 0.7 volts lower than the rest in the bank. 

I conducted a 20 hour at 5% of the battery capacity test and discovered that indeed 2 batteries were bad and 3 were marginal.

To conduct at load test you fully charge the battery bank and then put on a 5% load.  In my case 440Ah * 5% = 22 Amps. 

I only ran the test for 5 hours and the data clearly told a sad story.

This is really a bummer because the previous owner had replaced the batteries 3 years ago and I would expect much more from AGMs.  I diagnosed that the root cause is the Link 2000 charge controller.  The controller has been floating the battery voltage too high (28.3v).   So all that time at the dock, plugged into shore power, the Xantrex charger had been slowly killing the batteries.

Unfortunately there is no calibration procedure for the older Link 2000 units.

Rather than replace the Link 2000 I decided to put in a good high output charger that can be programmed.  I bought the Mastervolt 100Amp/24V model and I'm very pleased with it so far.  I can set the bulk, absorption and float voltage parameters with 0.05volt precision.  In addition to being able to properly maintain all my batteries with the charger I will also reduce the amount of time I have to run the generator for battery charging by 50%.  The unit can pump 100 amps into the domestic bank during bulk charging.

So out go come the existing batteries..... All 8 of them. 

....And in with the new Lifeline AGM 6V golf cart batteries.  Each one weighs in at 68lbs and it was a slow and methodical process to muscle them into place.  I bought these from American Battery in Hayward, CA.  Jim Ramos was really good to work with.  He gave me a fair "boat show" price and free delivery to the boat.  His driver was on time and hauled away the old batteries too.   I can't ask for more than that.

The Lifeline batteries were an exact fit for the existing MK batteries. 

A preliminary load test shows these new batteries are rock solid and and the new charger is floating them perfectly at 26.6 volts or 6.65 volts/battery.

Yes..... Got amps!