Victron DC-DC charger not charging very much

[Dave27]

I recently installed the Victron Energy Orion-Tr Smart 12/12-Volt 18 amp 220-Watt DC-DC Charger, Isolated (Bluetooth). I used the wire from the 7-pin connector with the truck. I used 8AWG to the charger, and 6AWG from it. Similarly, I connected the 10AWG ground wire from the 7-pin connector with 8AWG to the charger, and 6AWG to a ground on the camper frame. The engine start/stop recognition works fine, but when driving the charger is only putting 1 to 2 A into the batteries. When i start the engine, the input voltage is about 14.1v, the output voltage is 13.2v (this is the starting voltage on the lithium batteries this morning). The input voltage drops, and finally settles at about 13.5v. Based on the Victron smartshunt, only charging 1.96A. The Victron people don't know why this is happening. I am about to send it back. But before I do, I wondered if anyone else is using this, and has any suggestions?

If I send it back, I would look at the Renogy 20A DC-DC charger. Country Campers and Guest have connected their's to the wire from the 7-pin connector. So I don't know why the Renogy works, but the Victron won't. And if I go to the Renogy, I am still not clear how to wire a switch into it. I would appreciate more details of how to do it.

Thanks,
Dave

[ncitro]

Dave27 I have not used the Victron, but on my Renogy I ran new cables to the truck battery (40A version). I know Jim and Brian are running the 20A version through the seven way with no issue, but just to rule it out, if you have a set of jumper cables I would clip onto the input wires and clip the other end to the battery in the truck and see what happens. If you have a decent sized battery charger you could do the same thing. If the Victron comes to life and starts pumping out power you know its an issue using the truck wiring.

Also stating the obvious, but what is the SOC of your batteries. If they are near 100% they you will not see any current out of the DC to DC since they will be full.

[Country Campers]

Dave27

If I am reading the correct manual, there are a few different ones from Victron, Isolated and Non isolated, the switch or jumper wire is in the lower left. The manual states to remove wire and program the unit then reinstall the wire. With the wire installed the unit will be on all of the time. If you want to add a small switch to this wire to turn the unit on or off you can simply add a longer jumper wire and cut it and place the switch between. You may not have it programmed correctly or the jumper wire is not in place. If you can post a picture of the setup that would help, also the charger itself so we know which one to look up for details.

Brian

[Dave27]

Dave27 I have not used the Victron, but on my Renogy I ran new cables to the truck battery (40A version). I know Jim and Brian are running the 20A version through the seven way with no issue, but just to rule it out, if you have a set of jumper cables I would clip onto the input wires and clip the other end to the battery in the truck and see what happens. If you have a decent sized battery charger you could do the same thing. If the Victron comes to life and starts pumping out power you know its an issue using the truck wiring.

Also stating the obvious, but what is the SOC of your batteries. If they are near 100% they you will not see any current out of the DC to DC since they will be full.

The SOC is about 75%, the battery voltage is 13.18v. When I was testing it earlier there was about 10 or more amps going through, so I thought I was in business.

[Dave27]

Dave27

If I am reading the correct manual, there are a few different ones from Victron, Isolated and Non isolated, the switch or jumper wire is in the lower left. The manual states to remove wire and program the unit then reinstall the wire. With the wire installed the unit will be on all of the time. If you want to add a small switch to this wire to turn the unit on or off you can simply add a longer jumper wire and cut it and place the switch between. You may not have it programmed correctly or the jumper wire is not in place. If you can post a picture of the setup that would help, also the charger itself so we know which one to look up for details.

Brian

The switch I'm asking about is for the Renogy, if I change to that instead. The Victron is great as far as recognizing when the truck is running. I really like that feature.

[howson]

The switch I'm asking about is for the Renogy, if I change to that instead. The Victron is great as far as recognizing when the truck is running. I really like that feature.

Dave,
The D+ signal is simple to setup. Just tie in any 12v source that is only active when the truck is running (or when explicitly activated). See the diagrams and descriptions in my thread for a (lengthy, sorry!) explanation with diagrams. https://gdrvowners.com/forum/operati...e-battle-borns

Note I'm not advocating that how I did it was "best" or the "only" way to do it--the point was to show one possible method. There's any number of other possibilities depending on desired use mode. I like that it takes two distinct separate actions to get my Renogy to turn on and pass power to the batteries.

[Country Campers]

The switch I'm asking about is for the Renogy, if I change to that instead. The Victron is great as far as recognizing when the truck is running. I really like that feature.

Dave,

What I did was tie into the marker lights at the junction box in the pin box. I switched this line to turn on/off when desired. Using the marker lights, as I tow with them on, will turn on the charger if I have the switch on. I also wired power from a fuse panel that I installed to a switch and then to the charger, this will cut the output voltage in half, less draw on the truck wiring. I have run it both ways with no issues. The directions that come with the Renogy are very good with the explanation.

Any other help you need please ask. I hope you can get the Victron working, not sure why it is troublesome unless you just got a bad one.

Brian

[Dave27]

I used the smart shunt to document what the Victron dc dc charger is doing when I start up the truck. Before starting the engine, the lithium batteries are at 13.12v and discharging a little over an amp for the camper. When the charger recognized the engine started, the battery voltage jumps to 13.19v and over 15A are charging the battery (first fig). The voltage drops to 13.15v, and the charge to less than 3A in less than a minute or so. The graph (second fig) shows how quickly the voltage and current step down, and stabilize around 2A. The dc dc charger is in “bulk” phase during this time. Based on my experience towing about four hours yesterday, it will stay in this condition indefinitely. When the engine is shut off, the charger continues charging until it recognizes the engine is off, this just takes a minute or two. A graph of the shutdown sequence is in the third fig.

It doesn’t look like the SOK BMS is being triggered. This sequence seems to be governed by the dc dc charger logic. I am baffled by this, and I haven't gotten an answer yet from Victron reps. It may be a bad one, I'm about to send it back. At this point, unless someone can explain how the logic in the DC DC charger is supposed to work in this situation, I'm not inclined to try another Victron. I am doing some tests to see what happens if I don't use a DC DC charger at all. I will post that in a new thread.

Any input or suggestions are welcome. Thank you for the comments so far.
Dave

[ncitro]

Dave27 Again I do not have any experience with the Victron DC to DC, but I assume there are settings for the charge profile? What are they set for?

Did you try running it off of jumper cables rather than the 7 pin wiring?

[glennco]

Dave27

My previous truck was a Chevy Colorado and the manual stated specifically that the power going through the 7 pin was variable and not considered to be a high enough voltage to charge a battery.

Further research led me to believe the power going to the 7-pin would not be a raw draw off the battery but instead a variable amount from the alternator based upon what the truck was calling for to keep the starting battery charged.

I don’t know about the 2500, but that could explain the weird draw you’re seeing on the Victron.

[Dave27]

Dave27 Again I do not have any experience with the Victron DC to DC, but I assume there are settings for the charge profile? What are they set for?

Did you try running it off of jumper cables rather than the 7 pin wiring?

ncitro I haven't tried the jumper cables yet. It's a good idea, but the main thing it would prove is the 7pin wiring isn't adequate for the Victron. I'm really not interested in running a new thicker wire through the truck to the camper. The other thing it might help prove is this unit is defective, that could be useful in my decision.

the setting are shown in the attached figures:

[ncitro]

Regardless of whether you're interested in running cables or not, it would tell you if that's the issue. If it is, then you know.

Those settings look off to me. My Lion Energy batteries recommend setting the float and absorption voltages the same, to let the BMS in the battery handle turning charge on and off. I'm attaching Victrons settings for my batteries in case it helps you. It looks to me like you're going into float too soon. Setting the float voltage higher should resolve this.

[Dave27]

Regardless of whether you're interested in running cables or not, it would tell you if that's the issue. If it is, then you know.

Those settings look off to me. My Lion Energy batteries recommend setting the float and absorption voltages the same, to let the BMS in the battery handle turning charge on and off. I'm attaching Victrons settings for my batteries in case it helps you. It looks to me like you're going into float too soon. Setting the float voltage higher should resolve this.

Hi Neil ncitro
I used settings based on the recommendations from the battery maker SOK. I noticed the same thing about the float, I tried raising it, no difference. It is in bulk mode, and it has some different algorithm in selecting charge voltage. It starts at 14.1v, then drops, usually settling between 13.5 and 13.8v. Sometimes the drops are very steep and short, as far down as 8.5 or 10.5A. It's very frustrating and confusing.

I tried using jumper cables from the truck battery to the DC DC charger. It looks like it works! It started charging at about 15A, and settled down to around 10A. I would love those numbers, if they worked through the 7-pin connection. The graph is below.

Thanks, Dave

[ncitro]

Hi Neil ncitro
I used settings based on the recommendations from the battery maker SOK. I noticed the same thing about the float, I tried raising it, no difference. It is in bulk mode, and it has some different algorithm in selecting charge voltage. It starts at 14.1v, then drops, usually settling between 13.5 and 13.8v. Sometimes the drops are very steep and short, as far down as 8.5 or 10.5A. It's very frustrating and confusing.

I tried using jumper cables from the truck battery to the DC DC charger. It looks like it works! It started charging at about 15A, and settled down to around 10A. I would love those numbers, if they worked through the 7-pin connection. The graph is below.

Thanks, Dave

That is strange for sure. Unfortunately if it works off of the jumpers cables then I am not sure what would happen if you replace it with a Renogy. It sounds like maybe your trucks computer is throttling the alternator output, or possibly the output to the 7 wire harness.

I am going to defer to Guest here, I know he runs his Renogy off the 7 pin and is very knowledgeable about the GM trucks.

[mallstott]

For what it's worth, it was pretty easy to run a power cable up the drivers side to the battery on the 2500hd. Just follow the factory bundle all the way, then go up the fender. There's an unused fuse on the battery, you just need a nut to attach a cable (8mmx1.25). I ran 6 awg, which is overkill, but I didn't want to do it twice. Someone on the Victron site told me that the 7 pin wire would not be sufficient. I didn't test it.

-Mike-