question

You have probably got a smart alternator. Try reducing the shut down voltage and make sure the Orion has smart alternator set.

HI

yes, it is a smart alternator and is set to that. Shut down voltage is 13.1 currently. How low can you go?

With a smart alternator, you'll have to fuss with settings a bit. You'll need to set the Shutdown Voltage low enough that the charger will stay on even when the "smart alternator" reduces its voltage output but not so low that you continue depleting the starter battery even after you turn off the vehicle.

You may also be tripping the Input Voltage Lockout (you currently have it set at 12.5v) if your alternator, like mine, is known for occasionally dipping down to 12v or lower.

I presume that the green jumper on the DC charger is standard configuration and you don't have any switched wires on the L pin or H pin, correct?

If you don't have a multimeter to read voltage at the starter battery, that'll be very helpful for troubleshooting.

I recommend you set your Shutdown Voltage to 12.7v and turn off the Input Voltage Lockout feature. Here's why:

• A 100% SOC lead acid battery sits at about 12.78v. You're getting some voltage drop on the conductor from your starter battery to the DC Charger, so when the DC Charger is reading a 12.7v input value, your starter battery is almost surely over 12.78v (reflecting a .08v voltage drop. If you knew your actual voltage drop, you could set this figure to be more precise to account for that known voltage drop). This ensures you don't continue depleting the starter battery after you turn off the vehicle.
• When the alternator turns down its voltage output and the DC charger sees a lower input voltage, it will automatically derate its load on the starter battery/alternator as it approaches the Shutdown Voltage. So the DC charger may start with a 30 amp load and then reduce to, say, a 13 amp load as your smart alternator turns down its voltage. This keeps the DC charger from putting a load spike on your vehicle and potentially causing the voltage to dip rapidly (which might cause the DC charger to turn off).
• Once the DC charger sees an input voltage below 12.7v (your Engine Shutdown voltage) for more than 60 seconds, it will assume the vehicle is off and will turn off the DC charger load.
• You don't need the Input Voltage Lockout function right now because the Engine Shutdown Detection feature is performing that function for you. Unlike the Engine Shutdown Detection feature, which will continue to operate/charge for 60 seconds even if the alternator voltage drops below 12.7v (a feature to allow for smart alternator fluctuations), the Input Voltage Lockout will instantly stop charging if the alternator drops below that 12.5v.

Start there and fuss with the Engine Shutdown settings a bit to try to get maximum output from the DC charger. If that doesn't work, then you might have a temperamental smart alternator like I do that will require more precise settings and a switched input wire to the jumper H-pin: https://community.victronenergy.com/questions/100597/orion-tr-smart-121230-outputs-less-than-half-amps.html

Yes it is the 12/12-30 model. I do have a multimeter so I will do some checking of the voltage drop.

Thanks for such a detailed answer & suggestions, it's really appreciated.

Cheers