Lithium Batteries

This topic contains 7 replies, has 3 voices, and was last updated by  Seachange 2 years ago. This post has been viewed 1113 times

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  • #1255

    Seachange
    Participant

    Hi all, whilst I can’t add much value to the main Kimberley related topics until I actually get there I can let you know about a substantial change being made to Seachange’s electrical system at the moment. As part of her transition from quiet cruising to more hard core fishing she has developed a much larger thirst for electrical current, more bodies on board means more freezers, beer fridges, fans and general usage and the existing house battery bank has been struggling.

    So an upgrade is underway and in the next few weeks we will be replacing the 2kva inverter with an 8kva unit and fitting Lithium batteries in place of the original AGMs that were there. I won’t go into the reasons why I have picked Lithium here cos you can read all about them on the other forums on the web but I am looking forward to not panicking every time someone fires up the kettle, toaster, microwave, expresso machine or hot water without telling me first.

    I will let you know how it goes when we are done.

    Greg

  • #1303

    Ross
    Keymaster

    Hi Greg, 8kva inverter will keep plenty of beer cold!! I run a 3kva inverter on R&R, which is just enough to run all the fridges, freezers, engine room blowers etc. plus boil the jug, coffee maker and other small gear, but with some careful management of what is switched on at the same time.

    My problem used to be keeping the batteries charged without running the generator for excessive hours every day. Fixed that by installing a Whispergen DC Generator that automatically turns on when the house bank state of charge gets down to 70%. Now we average about 5 hours on the main genny per day when at anchor.

    With such a large inverter/battery capacity, I’m guessing you don’t want to run your genny all day. Have you made provision to charge the additional amp hours you are likely to use?

    Ross

  • #1306

    Seachange
    Participant

    Hi Ross, you raise an interesting point and to answer it accurately requires a slight technical answer.

    The short version is that lithium batteries can accept full charge current all the way to 100% whereas a lead acid must be trickle charged from about 80% thus resulting in excessive generator run times.

    With the new system in Seachange the new inverter can supply 200A at 24V so I can recharge from flat (20%) to 100% in four hours of Genny run time. Additional 24v alternators take care of charging whilst underway.

    With a bit of management I suspect we will minimise generator running to a couple of hours per day depending on air conditioning requirements.

    Greg

  • #1310

    Ross
    Keymaster

    Hi Greg,
    How are the lithium batteries performing? I’ve just started the process of designing a new Power Cat, probably will build it NZ. I’me now into research mode on all the new goodies on the market, and lithium looks like the way to go.

    Ross

  • #1312

    Seachange
    Participant

    Hi Ross, the short answer is the Litium Batteries are awesome, I am still getting used to them and have done 3 trips of approximately one week each since they were commissioned.

    Trip 1 (Mini Mini) – I went very easy on them and just monitored things like hourly consumptions, recharging characteristics etc as I didn’t really know what to expect.

    Trip 2 (Mini Mini) – The weather was warming up and I was more confident to push them with some Air Conditioner use and settled into a pattern for charging etc.

    Trip 3 (Lyndoch Bank) – Even though this is a long way out to sea the conditions were still and the boat quite warm. AC ran for the entire 30 hour run to the shoal, ran AC most afternoons for a couple of hours and again at crash time to cool the rooms down for an hour or so.

    The boat typically draws 30 amps at 24V under “normal” load (no AC or Hot Water) and at this rate uses 3% of capacity per hour. With a usesable capacity of 80% this is a theoretical run time of 26 hours before the Battery Monitoring System would isolate the load. The pattern has become to charge each afternoon/evening which usually starts from high 30’s to low 40’s State of Charge and the system charges at about 17% per hour until full (no trickle charging required). This results in approximately a 4 hour run time for the Generator using about 10 litres of Diesel during this time (confirmed via the recently added Maretron Fuel Flow system) which about a 20 litre per day saving compared to the previous configuration. During the Generator run time we heat water and run AC, if needed, to cool the boat plus I would make water if I had a RO plant (another project?). We could probably halve our typical load under extended cruising conditions with two or three on board but I would sure miss my ice machine.

    A new boat sounds very exciting as there are many gadgets that would make life simpler (but the boat more complex) but it is unlikely that we will undertake such a build ourselves. In the meantime Seachange has had her Davit rebuilt and is awaiting the arrival of a Cross Country 4.3m Tender as well as some ZF Electronic Throttle Controls to help me with docking as vision is limited and reversing gets interesting sometimes!

    Greg

  • #1336

    Ross
    Keymaster

    Hi Greg,

    I’m sitting around with nothing better to do after too much food and drink over Xmas and was looking thru the forum and noticed it’s been 12 months since your last post about your lithium battery system. Have you had any issues with the lithium batteries?

    I was really keen to use lithium’s in my new power cat after your story and reading all the data on the net, but my boat builder’s electrician, and one of the Aussie companies that are buying lithium’s from China and packaging them with their proprietary electronics and an USA brand charger, have managed to talk me out of them in the short term. Basically, they told me that if anything goes wrong with them in the Kimberley, I would not be able to fix them myself, or bypass a faulty battery and keep going on the remaining batteries. The tech talk is a bit much for me, but essentially it boiled down to the fact that the lithium batteries and their charging system is run by fairly sophisticated electronics and software. And if the software or electronics failed, I would be unlikely to be able to fix it at sea. They also mentioned something like, if one battery fails, it takes down the whole battery bank and charging system. Which is not really that serious if you are only a day or two from a civilisation, but it becomes quite expensive and inconvenient if you are 5-6 days or more from a major port with a tech capable of fixing the problem. Most well-built boats will have independent engine starting batteries and a generator to run essential AC systems if the house battery system failed, but it would be a major pain in the bum if I had to sail back to Darwin from Yampi Sound to replace a $20 electronic part, or install new software, because I couldn’t diagnose the problem myself.

    The short version of the story is that they said lithium battery systems on boats that don’t go far from civilisation are fantastic, but if the boat is heading into very remote areas like the Kimberley, or crossing oceans, then install a conventional lead acid system and wait a few more years for the lithium systems to be well proven.

    I also got the story from Dan (you know him) about how he flew to Bali to fix a Mastervolt lithium system on a new yacht, because no-one up there had any idea of how to fix the problem. He said his normal tools such as a multi meter were useless on the lithium and he couldn’t figure out the problem. In the end, after many hours of diagnostics and phone calls with Mastervolt, he downloaded software from Mastervolt and rebooted the system, which fixed the problem.

    I am still keen to use lithium’s on R&R II and have about 12 months to make my mind up. (Approx. 1000 amp hours @ 24 volts in the house bank of my new boat.) Has anybody else out there had experience with marine lithium battery systems and would like to make a comment?

    Ross

  • #1340

    Ross
    Keymaster

    Hi Ross,
    I installed a EV Power LiFe 400AH house battery to replace the 6 x 100AH AGM’s on Gemini Lady last year. Saved me over 100kg. We have been delighted with the performance and our Genset run time is down an estimated 25%. We have had no trouble using the existing charging systems on the boat with a few proviso’s from the research I did.
    1. Engine start battery left as AGM. Reason – LiFe battery discharge curve so flat that VSR would not isolate and protect charge in start battery.
    2. Voltage ripple when charging very damaging to LiFe so only 1 charge system operating at a time. ie. turn off solar when engines running.
    3. Set absorb time on all 3 smart regulator systems to zero. When LiFe reaches Absorb voltage 14.6V it is fully charged. Then drop to float at 13.7V.
    4. Limit alternator output to 80% so as not to overheat alternators. Reason – LiFe will take all the amps they can get and most standard alternators not designed to run at max output continuously.
    5. Limit charge rate to 20% of battery capacity. In my case 80 amps. Run 1 motor at a time as we do or use “small motor mode” on regulator to halve alternator output. Limit 240V charger to 80 amps. Reason – Battery manufacturer recommendation
    6. The new battery came with its own BMS and isolator which are connected in series with existing systems and will disconnect battery before it is terminally discharged
    7. Don’t rely on voltage or charge percentage for monitoring. Use only amps in and amps out and set Peukert equation in meter to 1.

    The only problem I have had is when motoring for a long time my alternator reg drops off float. The highest voltage I can set the re float to is 13.00V. As the discharge curve is so flat the battery would be significantly discharged before re float. Hopefully newer regs will get around this but for now I just turn off the ignition to reset the reg every few hours or so.
    Good Luck with it.
    Regards
    Tim Allen

  • #1708

    Seachange
    Participant

    Hi Ross, as you can see its been a while since I have been back to review these posts and have therefore been remiss in responding to you. I would still encourage you to consider Lithium over AGM for all the reasons that have been stated so far. My experience with them has been fantastic and their performance is life changing with respect to operating the boat.

    With respect to redundancy I can offer you the following information as it pertains to my system. I have 7 x 12V batteries configured as 3 x 24V and 1 x 12V banks, each of the 24V banks is paralleled to the charging circuits and also to the discharge circuits (each one can be isolated from either charge or discharge via relays). Each bank has its own BMS and each can be isolated individually if any fault is detected, this then reduces available capacity without losing it completely. I also carry a spare BMS to swap one out if I had a failure with the hardware.

    I guess I am pretty confident with it as I did the installation myself with assistance from Dan and the product supplier. My only “fault” experience to date has been a cell over temp alarm that settled down shortly after it was raised.

    The longest we has spent at sea with them so far has been 4 weeks and they have have run the boat every day with a 3 to 4 hour evening charge to top them back up……..sensational!

    Ross, please feel free to look me up next time you are passing through Darwin and i can give you the tour and I trust R&R II is progressing well.

    Greg

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