Finishing my boat install and had a quick question with Orion XS DC-DC. I asked this question on the old site but i still wasn’t quite clear.
Setup is an AGM Starting battery and 230 Ah LifePO4 house battery. I have a shunt and 712 battery monitor on the house battery. The main outboard has a 150 amp alternator. I also have an auxiliary trolling motor with an alternator but it only puts out 6 amps at idle and 17 amps at higher rpms. I’m proposing to wire both motors to the starting battery.
The ideal charging current for the LiFePO4 battery is 46amps at 14.4volts. So when the main motor is running at medium rpms, no issue. More than enough enough amps to support topping off the starter battery and giving 45-46amps to the Orion XS. However, when i’m idling on the main, or when just the auxiliary motor is running, which will be the majority of the time, neither alternator will be putting out enough amps to support the full 45-46amps.
So, I know I can play around with the engine shutoff voltage and programming to try and make it work. But, how would I go about setting up the program to optimize the charging? Most of the time, I will be on the auxiliary motor for 6-8 hours a day. It seems that no matter what I set the engine shutdown voltage to, when I’m on the auxiliary motor the Orion XS is going to be constantly cycling on/off and throttling back. Is that harmful or tough on the Orion XS? Shorten the life?
Sounds like the auxiliary motor is actually the main motor when it comes to your energy system, as it runs for the majority of the time. Personally, i would consider swapping the alternators, or maybe replace the alternator on the auxiliary engine with something like a 50A
Considering the Orion, its a relatively new product, and im sure Victron has done their testing, but its not yet old enough to really see issues with longevity. I would not be worried. All their other Orions and MPPTs are very reliable. And MPPTs do need to cope with changing input voltages and thus currents all the time.
You can set it up to hover at a smaller current than the maximum allowed, but its a very fine line. Looking at the manual section 4.2 you can see that it will modulate the current to keep the input voltage at the shutdown voltage. The issue in this might be the start. It will try to charge the lifepo at the specified max current, then if necessary ramp the current down. If the difference between charge current and max alternator output is too big, then im sure it will end up hunting/saw toothing. 6-17A of alternator output sounds like it might be not enough to reach a steady state at the shutdown voltage.
But you can try. Set the charge current to 10A for example. The orion should be able to reach a steady state, either at the 10A mark or at the shutdown voltage
Just confirming you’re running the latest xs firmware?
I cant change the alternators. Im still finishing the install so i dont know what firmware it has. I just bought the Orion about a month ago.
Ideally id like to just set it at 45 amps with maybe a 12.9 volt engine shutoff??? and let the Orion do all the management. However, if needed i supposed i could set the XS to 35 amps or something close to what the auxilary motor can put out.
The alternative, which others have done, is wire the auxiliary directly to the LiFePO4 house battery. I dont know the longevity of these setups. But ive heard since the alternator is so small that it doesnt generate enough heat to fry it. That doesnt give me the greatest confidence though.
Just pinging back on this. Curious how the newest firmware might impact the function.
Thanks