I am running a current model Isuzu MU-X with smart alternator. I have fitted a VSR to feed to a power board inside the cab of the Isuzu, feeding a fridge, plus 2-3 other 12V accessories.
I now want to fit a DCDC Charger to feed the Van battery, which presently gets charge from the Jayco "on-board" charger and a Solar panel.
My first question; can I leave the VSR in place and just take a fresh feed from the Isuzu battery into the van, OR must it be removed.
2nd Question; seeing that the van battery gets charge from the Jayco charger and solar, where would I tap in to connect the DCDC unit.
Simple and easist solution, have MU-X turn off the smart feature of the Alternator and have a 6B&S cable fitted from VSR to anderson plug at the rear of the MU-X then anderson plug at the front of the van that feeds the Battery and Fridge the KISS method wins out everytime.
-- Edited by Gundog on Saturday 15th of October 2022 11:00:37 AM
Thank you Gundog for your suggestion as it sounds like the way to go. Before I do, what is the impact of this measure on fuel consumption and exhaust / diesel particulate issues.
I have just watched a video, see title below, which, among other things, discusses the issue of de-activating the "smart alternator" of your vehicle.
It apparantly increases fuel consumption, by how much I do not know, but more concerning is the effect on exhaust gas emissions.
Vehicle exhaust gas emissions are certified (by someone / body) based on their design / operational data. Once the "smart" component is de-activated, it allows greater emissions, than it was certified to produce, and the certification is thus no longer valid, and Insurance Coy's will not cover the vehicle in the event of coming to grief. Not to mention warranty impacts etc.
Thanks again for your input, but this little cherub is going to buy a DCDC charger. Cheers
Smart Alternators: how they affect Caravans and Motorhomes.
If you look at the specs for DC/DC chargers, some are suitable for smart alternators, and some are not
I have not looked into this deeply enough to comment, as my vehicle does not have a smart alternator
Just have to buy the correct one, I suppose
I also have a Jayco built in, house (trickle) battery charger
It was fairly hopeless in keeping the house battery charged
I just removed the wire from the alternator at the Jayco built in, house battery charger end, (and isolated it)
Then went from engine battery (via fuse), to DC/DC charger, to house batteries
At the time I did not have solar panels, so when I fitted them, I wired them direct into the DC/DC charger, to house batteries
I have kept the Jayco built in, house battery charger, as all the stuff inside the motorhome is still wired up to it
I have just watched a video, see title below, which, among other things, discusses the issue of de-activating the "smart alternator" of your vehicle.
It apparantly increases fuel consumption, by how much I do not know, but more concerning is the effect on exhaust gas emissions.
Vehicle exhaust gas emissions are certified (by someone / body) based on their design / operational data. Once the "smart" component is de-activated, it allows greater emissions, than it was certified to produce, and the certification is thus no longer valid, and Insurance Coy's will not cover the vehicle in the event of coming to grief. Not to mention warranty impacts etc.
Thanks again for your input, but this little cherub is going to buy a DCDC charger. Cheers
Smart Alternators: how they affect Caravans and Motorhomes.
please supply the link to the video you watched.
I would like to see how the alternator changes exhaust gas emissions, and yes I agree fuel consumption could increase but the amount would be very small at a guess maybe 0.1%.
Your warrenty would not be voided if you dealer switched off the smart function in the ECU.
Your Alternater is a 120amp one and a decent 50/60amp dcdc charger is going to cost $6-700 and you still need to run 6B&S from your battery to the van where the DCDC charger will be located.
-- Edited by Gundog on Saturday 15th of October 2022 06:08:34 PM
I have a Jayco with a BMPRO J35B controller/charger. I think this unit has been installed in many Jaycos, before Lithium batteries became more popular. I rang BMPRO with questions about battery charging from the tow vehicle via this controller, when the vehicle's alternator is producing low voltage, like a smart alternator or a temperature controlled alternator.
The BMPRO support technician recommended installing a BMPRO Mini Boost in the system. I suggest contacting BMPRO support and doing some websearching for more details, if you wanted more information
I watched the video, and there are alot of misleading points made, it is basically an advert for DCDC chargers using BS to con potential buyers.
First off I doubt that your Mux would have regenenative braking banging out 15volts plus.
Here's a vid about disabling the smart alt on a ford ranger, in it he shows the voltages with it on and off. https://www.youtube.com/watch?v=NmdGxYe5ND8
My voltages never exceed 14.5v and generally after 5 or 10 minutes thaat charge rate settles to 13.8/9 wether I'm towing or not, I actually monitor my voltage output from the ECU with an OBDII port reader on an app called Torque.
