About Us

As long-time boaters, sailors and charterers, we wished that perhaps in our retirement we could travel in the Caribbean and take a longer voyage than a brief vacation would allow.  Then we had the opportunity to re-think our priorities.  We concluded there are no guarantees in life and boating can be hard work, so why not live our dream now?

We sold our house and moved aboard our new home, the Mar Azul, a Defever 44 Offshore Cruiser.  We made the tough decision to leave behind rewarding careers – Bob as a pilot, Elaine as a hospital administrator.  Along with our dogs Lady and Bandit, we departed from St. Petersburg, Florida on April 2, 2011, and together set off on a new course for our lives.

We plan to spend the next few years cruising in the Caribbean, exploring new places and cultures,  learning new skills, meeting diverse people and hopefully expanding our horizons.

Bob & Elaine Ebaugh

April, 2011

Responses

  1. Hi I really liked your info on lithium batteries; any regrets sine the install of lithium house battery ? Wendy and I sail Knot in Vein a Prout 38′ Cat presently in Antigua on the hard we return for 6 weeks sailing 2 or 3 times a year. Batteries need replacing so am looking at Smart SB100 100ahr lithium batteries to replace the lead acids there now. Cost $1300 each will put in 10 in the house battery, that’s why I’m still working! Any suggestions?

  2. HI Bob and Elaine: I too am considering installing Lithium Ion batteries. Your installation was in 2012. I would very much appreciate knowing if you believe the expense and complications of the change to Lithium were worth it. Any updated lessons? My email is . Any reply will be so appreciated, however brief.
    Thank you for sharing your experience in such detail .

    • Grant,

      We have not had any issues, besides perhaps a 20-25% decrease in total capacity. But we have been dock queens since returning to the States, so they only saw 1 year of hard use.

      I work on boats now, have installed a couple more LFP banks. There is no doubt they are a better mousetrap….but done right with a BMS and a complete review of charging sources, are expensive to install unless you can do the work yourself.

      On my boat, I could have replaced my FLA golf carts 3 times for the same cost, and probably have gotten a similar service life. So in my opinion, you need one of theses reasons to justify:

      1) size/weight – lots more usable capacity in a smaller space with big weight savings
      2) Only AGM Possible – the pricing looks better against AGM, but most times FLA will fit
      3) You like to tinker with boat systems

      And in all cases, you are a prolific cruiser spending lots of time on anchor!

      In that case, the biggest first bang is efficient refrigeration, and the best solar possible, if cruising in the tropics. Then look at batteries since this first step drives the needed bank size. Sometimes this may be prohibitive, in our case the whole boat is electric with 2 gensets and 4 refrigeration systems. Making that efficient = whole system redesign. But most cruisers are on sailboats with far less complexity. Point is you have to look at the big picture.

      Happy to answer any specific questions, drop me an email any time.

      Best, Bob

  3. Hi Bob,

    I’m glad to hear the LiFePo4 system is still going strong! I’m curious about your fusing and bussing arrangement though. From reading your article and dissecting the diagram on pg. 12, it really looks to me like you have 12 series sets paralleled together with fuses at the 3.4V and 10.2V points; less of a parallel/series configuration and more of a matrix. Why did you choose this route as opposed to a somewhat more conventional arrangement of four parallel packs connected in series with large (300A – 400A) fuses between them? Was it a busbar capacity issue?

    Something like:

    +12 0

    Where each Bn is 12 cells in parallel, individually fused with a balancer for the set.

    You state in the design article that adding fuses on the D1 links and middle C1 links would have eliminated the problem of a shorted cell overcharging it’s series link-mates, which it might do, but you’d have to rely on not just one, but three fuses blowing (and sometimes four, depending on the cell in question).

    I’d love to discuss further via email with nicer schematics.

    My current LFP installation isn’t so large, just a single 40Ah 4 cell pack for an Electro Scan MSD and an anchor windlass (more of an experiment than anything); but when the house batteries are dead, I’m planning on replacing them with LFP.

  4. Hi Tim,

    Thanks for reading the blog and asking a question. I will do the best I can to answer the question, but I’m not sure there is a good one.

    In my bank, there are 48 total cells. First 12 cells in parallel, call it a “string”. Then 4 strings are connected in series to create the battery bank of 48 cells. There are however many series connections between the strings, not just one. So yes…it is a matrix. And yes I get your description of 12 series with some parallel fuses comment…true. The objective of the fuses were to isolate a shorted cell.

    What I did was fuse every cell from its adjacent parallel neighbors. So the other cells in the 3V string won’t dump into the shorted cell. These parallel connections normally carry very minimal current, so a fuse as small as 5-10A would likely work. But these parallel connections are important for monitoring the string voltage. I only monitor string voltage (4 strings) on the BMS, if these connections were not present, it would be necessary to monitor all 48 cell voltages.

    That’s good so far, but now if a cell shorts, you still end up with a 9V battery connected to 12V. So that adds in the need for a series fuse. This needs to carry 1/12 of the Max current required for the bank. I don’t have these, so the design objective was not met.

    Ok…what I think you asked…why not 4 strings connected by only one series connection between each string? Was that it? In my bank it would have been feasible. I only draw a max of maybe 250A. I have one class T on the output of the bank, I’m not sure what 3-4 more would accomplish? To protect the cell you would still need the parallel fuses to achieve the objective, but it might eliminate the need for small serial fuses completely.

    Or maybe it was 16 strings of 3 cells each making 4 300Ah 12V batteries. Then the series fuses alone might just do the trick. But you would have to monitor 16 voltages.

    You mentioned balancers….against the wisdom of many manufacturers, I don’t believe rebalancing is required every charge. We seen several and heard of others that a bank properly balanced in the beginning just doesn’t drift without external influence. Further to get balancing to work, you must charge to or near 3.6V per cell. I see this as a maintenance event.

    Another consideration is evenly dividing the workload between the cells in a large bank. Please see:

    http://www.reuk.co.uk/Interconnecting-Batteries-for-Battery-Bank.htm

    Many make light of this, but I feel like it deserves consideration. And with 48 cells, it’s nearly impossible to solve…perfectly.

    I’m working on commissioning a boat with 160 100Ah cells, a catamaran that will have 2 banks of 1000Ah at 24V. Also did a smaller 12V 400Ah bank for a sailboat. Neither of those have more than the required Class T fuse on the output side of the bank. I still like the idea of protecting the bank internally, just haven’t come up with a method. If you can help…I’m excited to look at options!

    Best Bob

    Ps…sorry about the delay. I needed an hour to re-review some old thoughts to come up with this reply.


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