I recently installed two Orion XS 12-12-50 DC-DC Chargers and noticed that the output is 44 and 46 Amps respectively, not 50 amps. I used 1/0 wire and heavy full spec Lug connectors etc. Run is 50 feet or so from a dual alternator setup in my F-350 Diesel to 600 Ah of Lithium batteries in the trailer. I don’t think its wiring, I suspect possible settings. I drained the trailer batteries down to 60%, so I don’t think the charge is being reduced as it gets closer to full charge (ie above 80%) Should I reduce start voltage down from 14 v to 13. 6? I am not sure what factors would be preventing the system from full current charging.
What are the temperatures of the Orion units like? AFAIK they will derate when they get too hot.
Also, what are Input and Output current set to?
from the manual;
Input current: Limits the maximum current drawn from the input source. This
is particularly important to avoid overloading an alternator or other weak input
sources.
The value can be adjusted between 1A and 50A in 0.1A increments.
Output current: Limits the maximum output current.
The value can be adjusted between 1A and 50A in 0.1A increments
AFAIK, the two will talk together if you put then on the VE Smart Network, so if the network wants a total battery charge of 90A, then one or the other or both will have to back off to make the total not exceed 90A.
From the manual: With VE.Smart Networking, remote battery voltage, temperature and current sensing can be added to your Orion XS when paired
with a battery sensor like a BMV, SmartShunt or Smart Battery Sense. The Orion XS will receive the available information from
the battery and use that data to optimise its charge parameters.
What is your battery temp? If the two Orions start at 50A, but then back off, that might tell you something about the temperature somewhere (battery, or Orion) getting hot enough that the derating curves start to work.
RP>
They are not hot at all. The Input and Output are set at 50A each. The batteries are normal temp (22 deg C) and the Chargers started at the lower rate (less than 50)
The difference in amps is about 10%, not so much in my opinion, because the resistance of a 100 ft of cable (50ft positive cable and 50ft negative cable) is not negligible and is contributing to that voltage drop.
You might have to use binary troubleshooting to rule in/out some components.
As @alexpescaru mentions, the difference between 44 and 46 is small (5%), and between 46 and the nominal current (50) is only 10%, and could be attributed to cables.
If you label the chargers “46” and “44” , then swap their output cables over, and see if they still perform according to their labels. If so, this points (but doesn’t confirm) to the output cables being not relevant to the symptom.
If the charger labelled 46 now runs at 44, this points to (but still doesn’t confirm) the cables are constraining or at least influencing the top charge rate.
The reason that these tests only point to, and not confirm, is that with something as complex as a charger, there are many reasons that the charger might be derating the charge, including by not limited to;
- voltage drop (the MultiPlus will apply the “max volt drop = 1V” rule, and decrease the charge current until the voltage drop is < 1V)
- network rules (the first charger to power up might become a “master” and run under different rules than the subsequent chargers, i.e maybe non-masters have to derate first - I don’t know the programming so i’m guessing here)
- temperature (but you seem to have ruled this out)
- input cables or source not being able to provide enough energy
- What are your voltages? 50A on the input, if the input is say 13.6v, = 680w. Subtract about 10w for overheads (Orion = 98.5% efficient) = 670w, divided by say 14v, = 47.8A, so maybe 48A is perfectly expected?
What is your input current, and both voltages (input, and output)? You might just be hitting the efficiency limit.
RP>
1 Like
Voltages are 13.6 / 13.7 You are probably correct. 1270 watts is not too bad at idle (900 rpm) It also might increase when the engine is constantly at 1500 + rpm. I know i did rev things up and the amperages bumped up slightly. Cheers, G
Great, so for anyone else reading this;
The resolution is that this is a normal situation.
The reasons are;
- power out has to be equal or less than power in (due to conservation of energy)
- because the Orion has a running cost (i.e. like all devices, less than 100% efficiency) the power out must be less than the power in.
- Because the input voltage is 13.6v, if the input current = 50A, the input power = 680w
- The efficiency of the Orion is 98.5%, so the output power will be equal or less than 680 * 0.985 = 670w
- The output current will therefore be ~670w/13.7v (output voltage) = 48.9A
- The output cabling is long in this case, so due to the resistance the current will probably be even lower.
You should mark one of these posts as the solution so that the thread is marked as solved.
1 Like
This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.