question

Are you measuring the input voltage at the charger input terminals, or somewhere upstream of them? If the latter, make sure you retake the measurement at the input terminals and report back.

Is this a truck/RV application? If so, there are serious issues with using the 30A charger on the 12v auxiliary conductor. Namely, the fact that the Orion chargers are set up to put out fixed power and thus if the input experiences any significant voltage drop from the source you will wind up pulling a lot more than 30A on the input side. For such an application I would not use anything bigger than the 12A charger for this reason. Also, note that since the trailer brakes share the ground conductor with the auxiliary power circuit, your braking performance can be affected by how much current the charger is putting out because additional charger current means additional voltage drop over the ground conductor. Yeah, it's a crap design.

Thanks for the info.

Right now I have it on a bench with 18" wires, albeit undersized (12GA) for the loads they are carrying at the moment, so spot checking with a VOM and watching the Victron app.

It is an RV (camper van) where the power feed and load is independent of OEM vehicle wiring. The input is either a 120VAC > 12VDC power supply or via the engine battery. A relay that switches between the power supply and engine battery is triggered by an "engine running" signal on an up-fitter plug. So - providing the engine is running, the alternator will actually provide power.

I am OK with this behavior providing that it is operating as intended. If it is OK / as intended, then I can easily size wiring, relay, fuses, etc. appropriately.

The way I discovered this was in blowing a 30A fuse on the transfer relay I mentioned. In fact, it melted the plastic body so it was probably just above the fuse rating and it got hot before it actually popped.

What is your source of info on this unit?

Thanks!

Check the manual for the actual value, but it's designed to output more than the rated current for a short period to allow loads with a high startup current like fridges.

However it should not output more than the rated 30A for more than a few seconds.

Fuses vary in quality. And there are different types. Many 30A fuses will blow well below their rated value under a continuous current.

If you're worried about the current it outputs, check with an accurate clamp meter. Don't rely on fuse values.

Assuming it's a TR Smart model, standby current of the Orion is negligible. It can be connected direct to the starter battery with a suitable fused line. If you set up engine detection correctly it does not need a relay between it and the starter battery, it will switch on/off automatically. You can download a PDF on setting these up for smart alternators from victronenergy.com.

Battery settings in the Orion should match those supplied by the battery maker. 14.6V is higher than normal for many Lithium batteries, but there are some that need it.

30A draw on modern vehicles is generally fine. Check the alternator specs. Rule of thumb is to keep continuous output about half the rated value. Don't forget the vehicle loads like lights.

Yes - it is a TR Smart.

Understrand about inrush, but it was putting out 40A+ steadily for a period of time, then started ramping down before going into float mode when charging a 200AH Li battery with an internal 100A Smart BMS. The unit was always putting out significantly more than 30A until just before going into float mode. The battery vendor calls for 14.6 for charging and 13.8 float. The BMS (apparently) takes care of the rest to ensure the unit is not overcharged, etc.

This is the second Orion to behave this way. The vendor tested/replaced the original. They were not able to reproduce the behavior, but found a different issue and replaced it. That said, they did not have this lithium battery to test with - no a no fault found on the current topic is not conclusive in my opinion.

A relay is needed in this case because there are two possible power sources as mentioned above, and the power supply is not a battery charger. The Orion does not work well with a battery charger as an input, and lead acid batteries are not well suited for a "dumb" power supply as a charger. Won't go into the details, but getting the Orion, a charger and an alternator to work proved unreliable at best. And - I realized that high power chargers (remember, the Orion wants 40A+) are about 3-4x the cost of a simple power supply.

Agreed - there is more than enough power from the alternator to feed the Orion.

I finally just left the unit running and it eventually completed charging and consumption dropped to near zero (as expected). It consumed 600W initially (delivering 41A), then tapered down slowly to about 450W (30A) before going into float mode. I don't know the exact state of the battery at the start, but my guess is that it was at about 50%. The charge cycle took 2-3 hours. If we assume the average power was 525W (36A) over 2.5 hours, that is 90AH delivered. That feels like the right ballpark.

How did you measure the current through the Orion? They shouldn't produce this high a current for extended periods, but 40A for 10s at rated voltage. What was the output voltage when it was running at 40A? Guessing it was in bulk mode at 40A. Short circuit is 60A. And it's very odd that two different units did it.

Hi @COMO,

There was a change made to these units in 2021, please read this and see if it applies to your model.

I measured the current by taking the wattage consumed by the supply and dividing by the voltage (Ohm's Law). Though there are obviously some losses there and in the Orion, would that account for 10A? I guess maybe - an 80% efficient supply would put the power on the output at 480W, and that is 32A at 14.7. Bronze rated computer power supplies are 80%...

Output voltage was 14.6 when it appeared to be putting out 40A.

Though this does not account for losses in the supply and the Orion, I am guessing it is not too far off.

The SN starts HQ2131 (July, 2021?), so it is a post revision unit if I am reading the table correctly. I think I mentioned somewhere that the vendor replaced the original unit I had due to an issue he noticed that was not obviously related to this. I do not have the SN for that one.

I now have the unit re-installed in my van where I have an ammeter in-line with the battery. I will drain the battery down a bit, connect shore power and see what it draws.

Efficiency according to the manual is 87%.

Let's see what the ammeter says

Well, this is apparently a false alarm and I owe everyone an apology for wasting your time.

I discharged the Li battery to 50%, plugged the shore power in through the power meter, and saw 600W drawn at the wall, and only 27-28A (~400W) going to the battery. The input voltage off the power supply is ~14.5 and the output at 14.6, so there is little for the Orion to do other than limit current. So, there are losses of 30% between the PSU and the Orion.

This is saying that between the PSU and the Orion, losses are in the range of 25-30%. My guess is that the majority is in the PSU, but my guesses have not been very accurate so far! I should have known that the PSU was unlikely to be high efficiency and/or found a way to test it independently before posting here. Problem was I did not have a high current meter for my bench.

I am now a fan of this community and appreciate the input. I have and will continue to use Victron hardware. I already use Victron solar charge controllers, remote battery monitors, etc with zero issues. This is my first DC-DC converter based charging system.

I'll be testing this config over the next week or so on a road trip in my personal van (which will also use the alternator to charge when no shore power is available), but looks like it will be good to offer in customer builds, which was the original goal.

Thanks!

Actually not a waste of time.

As @Guy Stewart (Victron Community Manager) pointed out, there's derating due to temperature. But also there are some documentation updates needed.

So thanks for raising this, helps a lot.

You are welcome - glad it helped at least a bit.

I used the van over the last 8 days in a live test, and all is well.

Interesting is that I would have preferred that the output be limited to something higher than 30, conditions (that would not fail the Orion) permitting. On some shorter drives, the battery would not get energy fast enough to fully charge. The battery can handle up to something like 100A and the alternator delivers 180A (total) or something like it.

The absolute ideal would be to have a user programmable max input or output current, but that is not a complaint. It is rated 30A after all. Such a setting would be helpful if you had the input power available, and the battery was capable of handling more than 30A as in this case, and the Orion was OK with the resulting heat from whatever it needed to do...