Simarine Pico: Good ideas in battery monitoring & more

Ben Ellison

Ben Ellison

Panbo editor, publisher & chief bottlewasher from 4/2005 until 8/2018, and now pleased to have Ben Stein as a very able publisher, webmaster, and editing colleague. Please don't regard him as an "expert"; he's getting quite old and thinks that "fadiddling fumble-putz" is a more accurate description.

30 Responses

  1. Walter says:

    Like many Battery monitors, this one left out the battery temperture sensor. If your monitor doesn’t know the tempeture of the battery, its only taking a guess at when its fully charged. A fully charged battery at 10C wont be fully charge at the same set voltage as a battery at 30C. 10C battery at 100% SOC will be sitting at a much higher resting voltage, and counting amp flow alone doesn’t catch a system leak or bad cell. This is why the Trimetric and Victron and Maretron are the only recommened monitors from the professionals.

  2. Ben Ellison Ben Ellison says:

    Thanks, Walter, but you missed the fact that the big Pico shunts “precisely monitor battery voltage on 12V and 24V systems, battery temperature and continuous currents” at 300 or 500 amps.

  3. Anonymous says:

    I see now in the manual that its included on the large shunts. But I still stand by if its not included in all packages it reflects poor corporate governance.

  4. Dear Walter, a battery temperature sensor is always included in the package with all of our 300A and 500A shunts. I am sorry, we need to make this information more clear on our website. The quadro shunts SCQ25 and SCQ25T are not intended to monitor battery banks, but instead the current draw/generation of the light consumers (eg fridge) or generators (eg solar). That is why the temperature sensor is not included with the SCQ25 and SCQ25T, because monitoring tempearature of the consumers/generators would not have any effect . We are new on the market and we highly respect our competition you mentioned. And I am certain we will join the list of recommended solution for professionals after our system will be put to use. Kind regards, Jaro from SIMARINE

  5. Walter says:

    That clears things up greatly, Thank you for the quick correction. And a big thank you for actually monitoring Battery banks correctly. I did notice the puplished manuels appear to be missing sections, so hopefully the manuel will catch up soon. The rest of the product really intrigued me and now knowing battery temperture is included, I will diffenetly take a look when this because available in Canada. Thank you again Jaro

  6. Dan Corcoran (b393capt) says:

    Interesting. Much to like here for the price. Also, I like how the date/time/baro pressure is included. It gives more justification / function to taking up real estate in the cabin somewhere.
    4 shunts? Once I become curious about one device’s power needs, then I become curious about more than 4. Can there be multiple shunts?
    In regards to tank monitoring, how to deal with irregular tank shapes? Are there compatible sensors for measuring tank level by fluid pressure at the bottom of the tank? Would that work with bladder style water tanks?

  7. Very interesting, Ben (and Jaro)! I’ve been living with a pair of Link 10s for a looong time – something smarter would be nice 🙂
    Examining the catalog of products saved me making some poor assumptions – for example, the 25 amp limit on the smaller shunts can be doubled to 50 amps by combining two channels. Since I have a 50 amp AC charger, this was a relief!
    I agree that an N2K interface would be even better – especially if useful values could be displayed on my i70s (probably not, at least at present)
    – And I love the mounting – one non-critical 13mm hole! Raymarine, take note…

  8. Liberty NY says:

    This seems great, but as the user of 2 fantastic systems monitors, 1 whole boat with remote access and 1 dedicated 4-bank power monitor, both no longer in production nor supported by their vendors (both of whom are still in business)… the obvious question is which system AND vendor does a boat owner back with their $ today in the hopes that either will be around tomorrow?
    Let me add that on the subject of power monitoring, I’d like to see a return to current loops instead of shunts for measuring amperage. My old power monitor uses them, making installation trivial… just disconnect the power lead, slip on the loop, reconnect the lead, and wire in the sensor. These loops are pretty common parts. By comparison shunt installation is far riskier and more of a PITA.
    Regarding that big Q, Practical Sailor endorsed at least 1 of those products (perhaps both), and both were built by veteran firms, not startups. 1 of those products was created ~20y ago. The lessons these guys learned, as well as their commercial scar tissue remains invaluable. Perhaps their products were way ahead of their time, but neither is re-entering the marketplace today. So for both today’s new vendors and their prospective boat owner customers, both should invest/spend their $ in the recreational marine market carefully and with eyes wide open.
    (And yes, if I had the chance to revisit my $ spend on these 2 systems 15y ago, I would still spend it today… it drives me nuts that neither is still available.)

  9. Andy Brown says:

    Walter,
    RE: Temperature monitoring.
    As someone who has designed battery monitors with and without temperature sensors, I have a slightly different view on the matter.
    The battery temperature affects the total capacity of the battery. All that is really needed is to indicate the lowest expected battery temperature and that will reduce the effective capacity of the battery. For those monitors that don’t have the internal calculation you can manually reduce the capacity of the battery when entering it into the configuration parameters.
    As for full charge determination, almost every SOC meter (Balmar being the notable exception) looks for the charging current to tail off as the charger goes from bulk charging to float. In this case it is important for the charger to have a temperature monitor so that the battery is properly charged to 100%.
    Best Regards,
    Andy Brown
    Blue Sea Systems

  10. Walter says:

    When critical systems rely on a properly performing indication of SOC, a guesstimate is a fatal flaw. I could not reless Helicopters, or trust a remote renewable charge refueling station in the high arctic in my day job, based on a system that don’t understand the true SOC of the batteies. Nor would I trust a battery bank in an offshore vessel with people onboard based on a guess of SOC. A battery monitor that doesn’t take into account Battery tempeture can’t tell the difference between a solar panel or wind turbine output droping off instead of the batteries reaching bulk charge, counting Ah’s is only half the story because you can current leakage after the shunt, weather its internal of the battery or not. Batteries preform on chemical reaction, and every chemical reaction is 100% dependant on temperature. If I was to sail a boat north from the Baja to the Alaskan coast with a battery monitor not sensing battery tempeture. It would show fully recovered battieries at the end of the day when the solar panels stoped producing high amperage loads but the batteries are sitting at 14.4 volts. But the batteries really need to be sitting at a voltage closer to 15 volts when sitting at lower temptures. And to suggest the a consumer could make some calculated adjustment to make up for the lack of Temperature sensing is the problem I was pointing out above. 0.4-0.6 Volts difference is Substainial capacity when the difference betweeen full and damaged is only 3 volts. Its part of my professional career in releasing Aircraft to remote isolated destinations from -40°C to +40°C too understand that Temperature monitoring is absolutely critical. If your swapping batteries out every 3 years, often either your charger or your monitor is to blame.

  11. Ben – The Pico system is impressive, especially the beautifully designed displays – kind of the polar opposite of the 1950’s -style Smartgauge appearance.
    But where did your comment about “73% state of charge (SOC) — a near minimum for the long term health of many battery types -” come from?
    To the best of my knowledge, 50% depth of discharge was the rule of thumb, even for traditional flooded lead acid deep cycle batteries – and the focus in newer technologies, like your own carbon Firefly’s, is to drive that to 70 or even 80% discharged without impacting the long term health. Were you perhaps confusing the 73% SOC (charged) display with 73% DIS-charged?

  12. Ben Ellison Ben Ellison says:

    Hi Grant. I could have phrased it better and just tried, but I was thinking of some lead acid comments put up on Panbo when I first thought about replacing Gizmo’s house bank, like:
    “The key to longevity is minimizing recharge cycles; try not to discharge more than 25% and never more than 50%.”
    https://panbo.com/archives/2016/03/gizmos_house_battery_replacement_consulting_with_cole_collins_calder_schwab_you.html
    It’s the phenomenon RC Collins calls “Dead Lead”

  13. Hi Ben,
    I see that comment now, from Don Parker in 2016.
    I’m not sure what Mr. Parkers qualifications or experience are, or why he feels a 75% SOC threshold is a desirable target.
    I am familiar with the term “dead lead”, which quite aptly refers to the unusable portion of a batteries capacity as it affects long term battery life. I’ve also read Calder’s work extensively, and to a lesser degree RC Collins, and I don’t recall any cautions on discharging down to the 50% threshold.
    Frankly, if the house battery can’t provide AT LEAST that much useable capacity, it’s hardy worth considering, given todays improving deep-discharge technologies. Accurate battery monitoring, which the Pico system seems to offer, is certainly important in leveraging that advantage. Sorry if this is heading off-topic, but I couldn’t let that opening statement go completely unchallenged!
    Cheers,

  14. Compass Marine says:

    I have a few question about the Pico in relation to SOC determination.
    #1 How does the Pico deal with PSOC cycling as related to charge efficiency calculations and keeping SOC accurate during PSOC use?
    #2 Is the Pico smart enough to know the difference between bulk and absorption as related to the highly variable charging efficiencies during each stage? In other words is the charge efficiency a single factor such as minus 10% or minus 15% on the re-count or is it smart enough to track varying charge efficiencies during re-charging.
    #3 Can the Pico self-calibrate for charge efficiency on a full recharge?
    #4 How does the Pico deal with the Peukert effect on both the high amperage side (loads above the 20 hour rate) and low amperage side (loads below the 20 hour rate)? A battery bank discharged at a fraction of the 20 hour rating, as most house banks are, on average, will have more usable Ah capacity than one that is discharged at the 20 hour rate or one that is discharged in excess of the 20 hour rate.
    #5 Can the Pico track battery aging and declining Ah capacity?
    #6 Does the Pico use learning software or data tables to compare with expected behavior?
    #7 Does the Pico use any sort of SOC self calibration/correction such as comparing OCV to assumed SOC during periods of zero current flow?
    #8 Is this an entirely new Ah counting software developed by your company, or an adaptation of the existing Ah counters already out there only in a nicer GUI?
    Thanks in advance.

  15. Ben Ellison Ben Ellison says:

    I am so sorry if you are having trouble leaving a comment! Panbo security settings were recently changed and regular site visitors must clear their browser cache of site data in order to make registered or even anonymous comments. The command “Control-Shift-R” should do the trick on a Windows PC and I’m collecting info on how to clear other caches here:
    https://panbo.com/forum/2017/09/panbo-comment-problems-92017.html

  16. Ben Ellison Ben Ellison says:

    Thanks, RC; I’m hoping your questions will spark more discussion with Simarine and others here. I’m also happy to see your work on your new website, particularly this very relevant entry:
    https://marinehowto.com/programming-a-battery-monitor/

  17. Ben Ellison Ben Ellison says:

    Hi all: I am so sorry if you are having trouble leaving a comment! Panbo security settings were recently changed and regular site visitors must clear their browser cache of site data in order to make registered or even anonymous comments. The command “Control-Shift-R” should do the trick on a Windows PC and I’m collecting info on how to clear other caches here:
    https://panbo.com/forum/2017/09/panbo-comment-problems-92017.html

  18. Andy Brown says:

    Walter,
    I think you are misunderstanding my point.
    First, we aren’t talking about monitoring helicopter batteries in the Arctic, we are typically in a more controlled environment where the battery temperatures are moderated by the water.
    Second, all battery monitors drift overtime and can only be synchronized by approximating the capacity based on the Open Circuit Voltage or re-syncing once we have 100% state of charge. As best that I can tell, all marine based battery monitors determine state of charge once a particular voltage and current threshold is obtained or if an open-circuit voltage can be calculated. Solar power often fools these monitors into thinking the battery is 100% charged thus triggering a synchronization event. It is a tricky problem that I’m not sure anyone has found an optimum solution.
    In any case we know that the apparent capacity of the battery decreases as the temperature drops, thus you can plan for a worst case temperature scenario by under stating your capacity. (You are going to want to plan for that anyways).
    If you dig through the math you will find this is exactly what is happening internally in the SOC monitors.
    The whole thing is further complicated in that the capacity of batteries vary widely from the published data (usually less).
    As an added bonus, shunts are typically 1% and the meters are also roughly 1%, they also ask you to enter Peukert’s exponent and how accurate is that number?
    BTW, as far as temperature monitoring, I am only talking about capacity monitoring. Your charger should always monitor temperature.
    Hope this clears up some of the misunderstanding about how SOC is calculated.
    If anyone has any questions, catch me at METs or contact me at Blue Sea Systems.
    -Andy

  19. Dear all,
    here are the answers to some of the above questions.
    #1, #2, #3, #6: Pico’s algorithm is not a simple Ah counter. It is constantly monitoring battery current and voltage and temperature.
    These data are compared to the internal battery model and its parameters are constantly being adjusted so that the model fits to the actual data.
    The algorithm needs some time to adjust the parameters (learning phase) and it will improve accuracy during the first few cycles.
    #4: You can can input battery capacities C/20, C/10 and/or C/5 in battery settings.
    From these data, Pico can calculate Peukert.
    #5: The screen for monitoring battery health (declining capacity) is not yet available in current firmware.
    But Pico is capable of detecting these changes, and the screen will be available in one of the firmware updates in the near future.
    #7, #8: Yes, since Pico is constantly measuring voltage and current (not only during periods of zero current flow).
    So it is not only a simple Ah counter with a nice GUI, its algorithms are much more complex. It also shows you SOC for the battery without the shunt, but of course this value is not as accurate.
    And last but not least, it is also a tank monitor and a barograph.
    Kind regards,
    Jernej – Simarine

  20. Javier says:

    Hi,
    I´m a follower of your web from Europe, really cool site, I just want to share my experience with PICO, just purchased PICO battery monitor Active shunt S300 and SC07. I really like the touch screen and its resolution really cool, also for the same amount of money you have some extra features like tank,temperatures,baro meter… monitoring. I really happy with this device and I can´t wait to get the future NMEA2000 bidirectinal hands on. I think it’s worth every cent, and I want to pay for it.
    I got in touch with Simarine due to a software bug and post sales support was flawless.
    Cheers,
    Javier

  21. serenity says:

    “While it’s helpful to see a boat’s major DC current consumers and generators in real time, I think that the holy grail of power management is logging that info for analysis.”
    Victron has been doing this for a long long time with their FREE VRM portal.
    I can see daily and monthly usage for ac/ dc / solar, plus I get warnings if any of the alarm settings are met
    Many of these devices reviewed by you also want a monthly fee, and Victron with their VRM has been providing the fore free

  22. Ben Ellison Ben Ellison says:

    Thanks, Serenity; I agree that the VRM portal looks great, but that’s why I linked to this Victron entry in the Pico discussion above:
    https://panbo.com/archives/2017/04/news_victron_venus_cruzpro_sog2_dy_windsense_vaavud_ultrasonic_panbo_news.html
    Also note that none of these services is truly free if they only work with particular hardware, Victron does not provide the communications link between boat and cloud like many monitoring systems with subscriptions do, and I don’t think that Victron has a multi-shunt like Simarine’s.

  23. Mikedefieslife says:

    I was just about to pull the trigger on the Victron smart battery monitor. The latest version has bluetooth built in so no need for separate dongle.
    Now I’m unsure. The Pico is slightly more expensive but seem more flexible. The Victron is widely used and acclaimed by cruisers and liveaboards.
    The Victron app has a nice clean interface with historical data immediately available. Using the Pico demo, I can’t see where you access historical data.

  24. Ben Ellison Ben Ellison says:

    Congratulations to Simarine on the DAME Award they just received for the Nereide Smart Power Panel in the Electronics category.
    https://www.metstrade.com/innovation/dame-winners/

  25. Arthur says:

    I just ordered a PicoOne Package from Simarine website. Can’t wait to install it on my 29ft Open Bow. I am not as experienced with Boating electronics as you guys. Hope it won’t be too difficult to install. I believe the future of boating is here now especially when the NMEA2000 module is released. Then we can see all the data on the Pico Monitor. Simplistic Hardware Platform + Minimalistic Connections + Cellphone is the way to go!

  26. Hein says:

    I just finished installing a Pico system: display, tank sensors, 2 300A shunts for house battery and engine battery and further shunts to measure solar, shore charger and alternator currents. It’s definitely very simple to install with each unit linked together via individual data cables (either daisy-chaining or hub and spoke or a combination of the two, if you get my point) and then the rest is a matter of setting up the Pico itself. Tanks still need a bit more calibrating and am still getting up to speed with the SOC routine, but all in all I am extremely impressed. To be honest, I am not that concerned about the SOC, but am very happy for having been able to take out yards and yards of wiring, switches and circuit boards (the previous set up) from my boat which was beginning to break up…

  27. luis soltero says:

    Hello All,

    Just finished installing a pico monitor with 2x 501, 2×301, and 2xSCQ25 shunts and impressed at how simple the installation was and how well the data from all these shunts is displayed. I would like to add a couple of comments not detailed above.

    One of the problematic monitoring issues that I have been dealing with for many years has to do with the transfer battery at the opposite end of my boat used to run the windlass and bow thruster. Originally my 7x 8D bank of AGM batteries were monitored with a 500AMP shunt originally by a link 2000 then a magnus battery monitor. The transfer battery was connected directly to the house bank with large battery cables and current drawn from the windlass/bow thruster were not counted although this 4D battery was part of the battery bank.

    The Pico supports additive shunts. This means that you can have several shunts on either the return or positive side of the house battery and “add/subtract” the current coming out of them. So…
    1. you can draw more than 500 amps from your bank through multiple shunts
    2. you can monitor current draw from different subsystems connected to the house battery (in my case the bow thruster and windlass)
    3. you can have the pico keep track of the math…

    A second nice feature is that every 301/501 shunt comes with a temperature sensor. In my case I have made a point of using all of them. I have 4 sensors configured as follows.
    1. Battery compartment temperature
    2. Engine compartment temp.
    3. Engine impeller temp. This is temp. This is important given that the temperature differential between the impeller and the water is constant. A change in this temp difference suggest increased friction predicting a failure well before it happens.
    4. engine block temp providing a much more accurate reading than the gauge on control panel.

    finally its really nice to be able to monitor the independent output of my 7 solar panels.

    All in all very impressed with the unit.. and IMHO the cost of the unit is quite reasonable for what is provided… a rare thing in the marine industry.

    take care.

    –luis

    • Ben Ellison Ben Ellison says:

      Thanks, Luis. Sounds good, but I have questions:

      1. Can you custom name the various shunt and temp sensors so it’s easy to see what’s happening on the monitor?
      2. Do the shunts give you current draw totals over a certain period as well as live draw, and assuming so, what are the reset options?
      3. Are you seeing some or all of this data coming out over NMEA 2000?

      I also saw your comments on the SeaKeeper entry and sounds like the big upgrade projects on Bliss are done and you’re underway or in trial mode?

  28. Luis Soltero Luis Soltero says:

    Hi Ben,

    1. Yes… the simplest way to do this is to use the mobile app. I used it on my iPhone. You wifi connect to the unit and then run the app. Note that the wifi on the pico can be configured as a stand alone Access Point or as a client to your vessels network. Once connected to the app you can
    a. change the name of any shunt
    b. change the polarity of the shunt (ie consumer/producer on + or – bus)
    c. create a battery bank and assign shunts to it.

    all pretty easy to do. You can download the app and run it in demo mode to see how it works. go to setting->devices->shunts to see how to name a shunt and set its polarity and “add” it to a battery bank.

    2. as far as I can tell tracking usage over time is not currently supported. However, I see no reason why this functionality could not be added to the app even of the Pico itself might not have the memory resources to store the data. I could be that this is a planned feature.. not sure. we should probably ask the company.

    3. there is currently no support for NMEA2K for this device. however I did see this on the FAQ on their website…

    No yet, currently we do not support NMEA 0183 and 2000 protocols. However, a bidirectional module will be available for purchase in Q1 2019.

    so it seems that that is coming.

    and yes! SK5 installed and operating. Putting the final touches on bliss refit and then we are off. Plan to head north round May 1.

    take care,

    –luis

    • Ben Ellison Ben Ellison says:

      Happy to report that I just added a gallery of Pico photos that Luis took to this entry and am working on an entry about his impressive dual alternator and SeaKeeper systems (which I saw in July).

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