i have a Smart Battery Isolator fitted to my vehicle and the auxilliary side runs to an Anderson plug at the back of the vehicle. This is my conundrum - with the engine off, the vehicle battery is reading 12v and the led on the SBI is off, the start side terminal on the SBI is reading 12v and the auxilliary side terminal reads 0v but I am reading 12v at the Anderson plug?
The setup was professionally installed but my logic tells me that there must be a secondary source of start battery power feeding into the cable that goes to the Anderson plug. Does that sound right? If it is then: (1) why dont i read a voltage at the auxiliary terminal on the SBI; and (2) is the SBI is basically being bypassed as far as protecting the start battery goes?
Wow, you don't muck around when you ask curly questions do you :lol: OK, is the 12v at the Anderson plug with the van disconnected? If yes, do you have a second battery in the tow vehicle that might be connected to the Anderson plug as well? If that might be the cause, try disconnecting that second battery and see if the problem still exists. If that fixes it, then there is also either a diode or a DC to DC charger after the battery isolator (Voltage sensing relay or VSR) that is blocking the second battery from sending voltage back up the cable to the VSR. If the voltage is still there, then you are looking for another wire linked into the positive wire at the rear Anderson plug and that could be draining power directly from the start battery. The diode or DC to DC charger is still the reason you don't see any voltage on the out going side of the VSR.
Was that explanation as clear as mud :lol:
T1 Terry
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i have a Smart Battery Isolator fitted to my vehicle and the auxilliary side runs to an Anderson plug at the back of the vehicle. This is my conundrum - with the engine off, the vehicle battery is reading 12v and the led on the SBI is off, the start side terminal on the SBI is reading 12v and the auxilliary side terminal reads 0v but I am reading 12v at the Anderson plug?
The setup was professionally installed but my logic tells me that there must be a secondary source of start battery power feeding into the cable that goes to the Anderson plug. Does that sound right? If it is then: (1) why dont i read a voltage at the auxiliary terminal on the SBI; and (2) is the SBI is basically being bypassed as far as protecting the start battery goes?
First off I have no qualifications.
Isolator will totally disconnect when voltage drops below 12. Something, maybe 12.6 or 12.4 volts.
We have a light in the ute and often go to use it and halfway though doing something the power drops below the set target light goes out.
T1 Terry. Yes the Anderson is disconnected from the van and no there is no second battery. I think I am going to have to trace the wire from the SBI back through the vehicle. There must be another feed coming into the line somewhere.
Just because it was professionally installed doesn't mean it was done right . Brother in law had a second battery and a redarc bcdc charger installed by a professional , looked pretty but was wired wrong and over $1000 of gear was just sitting their but not charging .he only realist this after running out of power to his car fridge .
I suspect I'm in over my depth here, however it sounds to me like the positive on the Anderson plug is wired to the wrong side of the SBI. To my knowledge isolators come in two forms, one is wired to the ignition and the other simply works on voltage, so if the start battery hits 12.7volts (for eg) then the isolator assumes the vehicle is running and opens the switch, if the vehicle battery has more than 12.7 volts when switched off the isolator will remain on until it drops.
If no then take it back to whoever installed it and have them go it properly.
If yes then remove the load wire from the SBI and then retest the voltage at the Anderson plug.
Also check the size of the wire at the Anderson plug and at the SBI. It should be 6 or 8mm, much thicker than other wiring.
The wiring to and from the load sides of the SBI to the battery and back to the Anderson plug should be a minimum of 13.5mm sq conductor, but the bigger the better. A 50 amp Anderson plug can only accept 16mm sq conductor, so if you go bigger you will need a higher capacity Anderson plug just to get the cable into the lugs, but I have seen modified lugs where a bigger crimp lug cable joiner has been silver soldered onto the 50 amp Anderson plug lug allowing it to accept 25mm sq cable (3 gauge AWG). The plug and contacts are only rated for 50 amps, the bigger cable is to minimise voltage drop.
T1 Terry
__________________
You can lead a head to knowledge but you can't make it think. One day I'll know it all, but till then, I'll keep learning.
Any links to any sites or products is not an endorsement by me or do I gain any financial reward for such links
