Monitor caravan power with BC300

How to monitor caravan power when using an inverter or a CPAP machine? One of BMPRO brand ambassadors, Mark Simpson, shares his personal experience in using BC300 for wireless monitoring of high currents and directly connected loads.

With technical background in IT, Mark loves gadgets and data. He travels a lot with his son, going on 4×4 adventures, in his Prado with the swags. When travelling with his wife and two gorgeous dogs, Mark is enjoying the comfort of his new Jayco Journey.

Mark’s story:

“My wife, Lee and I have a 2018 Jayco Journey touring van, 22 foot long. It is big, it is beautiful and it’s ours. We recently did a short 4-day weekend trip (with the two fur babies) where we were in a van park with 240v available, but I wanted to test 12v systems we have installed, before we head off on our big trip next year.

Lee and I both run CPAP machines at night, so being able to monitor the power draw through the inverter is very important to us. However, the standard BMPRO J35B with JControl panel in our van could not manage/monitor this draw as it did not know about the inverter, which is hooked up directly to the house batteries. I contacted Team BMPRO and they suggested the BC300 300amp shunt with CommLink connected to the J35. We took it with us on the above trip for me to install.

Testing BC300 and unexpected findings

The first night away, without the BC300 connected, we used more power than I anticipated. The next day I installed the BC300 with CommLink to my house battery bank (2 x 120ah batteries). Negative terminal on one battery and Positive terminal to the other. Plugged the CommLink into the J35, easy as pie. The CommLink device connected to the BC300 via Bluetooth as documented. So it was really a simple install.

A quick test on the power draw through the inverter, by making two really nice cups of coffee, freshly ground beans, steamed milk, yum, with the Barista Express. The JControl saw the power draw of the coffee machine which proved to me the BC300 and CommLink was doing what it was supposed to do. Brilliant.

Now to test the draw of those CPAP machines.

My machine is an older one, it measured 1.5 amps, so not too bad and that was with humidifier connected. My wife’s machine however is a new ‘super efficient’ super quiet machine. This sneaky little thing was drawing 6.5 amps. Efficient, not so much… Investigating, I found Lee’s machine’s humidity was set really high, so i adjusted it down to match mine. Now its power draw was less than 1.5, more like 0.7-1.0. Winning.

I guess it just goes to show the BC300 with CommLink really help monitor the power draw when an inverter is used. In our case, it helped identify how much power the CPAP machines were using and allowed us to adjust accordingly.”

If you are using an inverter, monitor caravan power with BC300 with CommLink. They allow monitoring the currents drawn from the battery much more accurately and keep total control over your power needs.

BC300 is designed to be used with BMPRO power management systems, such as BP35 and J35. It communicates with the units via Bluetooth and CAN BUS. 

Like this Post? Share it!

Share on facebook
Share on linkedin
Share on email

15 thoughts on “Monitor caravan power with BC300”

  1. Just wondering what sort of CPAP Machines were being used. I use a Resmed S9 with H5 Humidifier with the appropriate Resmed 12 volt adapter. I just recently experimented with mine on a dedicated battery alone with the both the Heater and Humidifier turned off on the machine. This worked a treat and I had at least 6 comfortable nights averaging 6.5H sleep without recharging the dedicated battery.

    1. Olga kustova

      Hi Alan, I have the same machine, Resmed S9 Autosense with H5 humidifier. My humidity settings was at 23c.
      My wife uses a Resmed Airsense 10 for her, her humidity setting was at 30c, so used a lot more power.
      No 12v adapter, no 12v battery. This was connected directly to the inverter with the same plugs and power packs we use at home.



      1. Hi,
        The picture above shows 2 x battery’s hooked up in parallel, the shunts location is monitoring negative current flow from one battery’s terminal ? Leaving a clear negative path of lesser resistance for consumers to the second battery. Is this calculated or compensated in the shunts programming ? Or am I missing something here. Wouldn’t it be necessary to hook the battery’s In parallel then monitory only one negative current path for the battery’s system.
        I have left several voice messages trying to get assistances with this however have herd nothing.

          1. Thanks David,
            Have been in touch with techs today and would seam that the battery’s DO need to be firstly hook in parallel then then full negative current flow monitored as mentioned. Maybe a good idea to put this in a manual or change the above pic when two or more battery’s used in parallel, also we have friends who have recently brought a new Jayco Crosstrak and Jayco from new have also wired the BC300 only from one battery negative terminal.

    1. Olga kustova

      Hi Luke, for parallel setup, it doesn’t matter if it is two batteries or four. But the positive should come off one battery and all the negatives via the BC300 shunt off the other battery with fused linking cables between both batteries. Ideally the linking cables should be the same length between the batteries and fused.

  2. Will the BC300 work with the Drifter Control Panel given it has its own shunt when installed? Or is it more suited to the J Control or Trek Battery monitor?

    1. Olga kustova

      Hi Brent,
      The BC300 is not compatible with the Drifter, it will only work with the BMPRO Battery monitoring systems that use a CAN BUS system.
      Steve / BMPRO Customer Service

  3. I have a BC 300 on my Jayco Crosstrak. I’ve wired in an Anderson plug with 2 portable panels on it. Currently got 2 fridges running which are managed by the J35. I’ve got 2 100ah Ritar Gel batteries. The comm link is showing green.

    I can’t seem to figure out the amps on the app. It says my Output is zero amps. Battery consumption is 4.8A. Solar is at 3.6A.

    How do I know whether the Comm link and the J35 are playing together?

    1. Olga kustova

      Good afternoon Mark,
      You will know if the BC300 is working correctly with the CommLink as they will both flash green. If there is a communication drop the commlink will flash red.

      Kind regards,

  4. Russell Masterton

    Before connecting a BC300 Shunt and Commlink to my Goldstream 1500 Remote van. the Trek display unit showed >199 hrs remaining from the single 100ah lead crystal battery. After connection it showed 79 hrs and discharging. Surely this can’t be right? Is it something I have or haven’t done?

Leave a Comment

Your email address will not be published. Required fields are marked *