This Review of the BMPRO JHUB-J35C RV-POWER MANAGEMENT SYSTEM (RV-PMS) examines its auxiliary circuit capability to charge a recreational Battery from a towing vehicles alternator. For a Campervan-RV to be suitable for self contained living including of grid camping we rely on AUX-charge, Solar-charge and possibly a generator. The minimum expectancy for a charge system is to keep a fridge going 24/7 every day while travelling for 4 hours a day.
In my opinion "Self contained living" in a solar equipped van implies that a one way fridge (12V) can be maintained 24/7. That does not appear to be the case. The capability of this Battery Management System has been assessed for its ability to sustain a fridge 24/7 and provide sufficient daily re-charge the batteries from the vehicles alternator and the Solar panels. Under spec'd systems will require access to AC Mains power (the grid) every few days.
So, how does the JHub system fare ?
I have travelled more than 10 000 km and tested the system extensively. I have experienced black outs multiple times and been forced to return to the grid frequently after just a few days off the grid. The system is not sufficiently capable to guarantee that the fridge stays on 24/7 in spite of me being very careful with energy use for any other purpose than running the fridge (i.e. lights, TV, pump, showers)
What's the problem ?
The BMPRO JHUB-J35C under performs in AUX charging mode as well as in combined AUX and Solar charging mode. A Solenoid bypass installed by Jayco appears to proof my point that BmPro's JHub suffers from charge deficiencies. Further proof is that BmPro offers a Miniboost (to be paid for as an Aftermarke improvement). It is designed to boost AUX charge. But in my opinion neither the crude solenoid (battery isolator) in the BMPRO-J35 circuit, nor the Miniboost make enough of a difference. Modern vehicles have smart alternator charge system.
The BMPRO Miniboost is offered as a necessary Aftermarket system supplement (not installed by the OEM Jayco). With Miniboost installed the Jhub-J35 performs reasonable at 15A (spec rates Miniboost capability at 18..20A). Jayco's original thin wiring for the J35-Aux Input appears to be sufficient to drive 15A when a Miniboost is installed. The Miniboost seems to outperform the thick wire Redarc solenoid bypass that Jayco has installed to boost the AUX charging mode. Now the weakest link is the J35's charging algo. It is capable of running a twin charge mode, but often selects only one charging source, i.e. either AUX or Solar instead of both.
What can be done to solve the problem ?
What I would expect is that AUX charging and Solar charging via J35 work in tandem all the time full blast until the House battery is at least 80% charged. The currently implemented charge source priority & activation algo that tests loads should only kick in when the battery is nearly fully charged (if at all). Furthermore the J35 may to often give the highly fluctuating solar charging circuit dominant source preference. With a Miniboost installed and only one solar panel available in a FD19, Solar is always the weaker source compared to AUX (15A constant vs 9A max). If we can get 15A+9A=24A most of the time, then the fridge (4A) can be sustained in a typical mixed cycle of daily driving and occasional sunshine.
Considering that Jayco and Setec are in a system development partnership and that none of their Engineers are accessible to their customers is frustrating. It takes lots of emails with their respective Service departments to slowly get a picture of the systems performance. I can see no valid technical reason why the "in vehicle charge mode" for the RV house battery should not be more comparable to BMPRO's powerful AC charging modus for the grid. The JHub has been promoted as an advanced technology innovation that makes system modifications fast and easy (via Tablet). So lets hope that Australia's dominant mass manufacturer of Australian RV's (Jayco) and their System Partner (BMPRO/Setec) will be able to improve the JHUB soon to reach its full potential.
In AC charge mode The JHub system bulk charges with 15A from the grid and provides additional current to power all loads. This is quite acceptable for charging one 100Ah battery, but marginal for 200..300 Ah battery blocks. The off grid J35-AUX/Solar twin charge mode in my opinion only deserves 2 stars.
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BMPRO JHUB-J35C RV-POWER MANAGEMENT SYSTEM (JAYCO FD19 CAMPERVAN-MOTORHOME)
Available in Australia since early 2017, BMPRO’s JHub is one the World’s first portable power management systems for monitoring and controlling caravans and motorhomes, operating from Android tablet. Designed specifically for Jayco Australia
https://www.jayco.com.au › Blog › Prepare for your Adventure
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