Lithium safe converter

[Guest]

John303 ,

I'll check my output voltage from my truck while disconnected from the trailer. I didn't check the wiring on the truck but the trailer wiring on the pollock plug looks like 10 AWG. The decision was made to disconnect the 7 pin charge wire from the frame mounted breaker and connect this directly to the 8 AWG and on to the DC DC input. This would help with the voltage drop since this is around another 12ft of wire. My charger is not isolated on the negative side from the 7 pin which runs though the pollack trailer plug and to the trailer frame in the original location. However the negative input to the dc dc is from the negative busbar and the output also runs back to the negative busbar. The negative busbar is grounded to the left side of the trailer frame via 4ft of 4AWG welding cable. I was initially concerned about this ground loop type condition since the Renogy is a non-isolated charger but I cleared this with an EE friend from work. The positive wire from the truck is isolated and ran directly to the input of the DC DC charger.

The link you provided looks like a 30 amp charger where I was able to find an 18 amp output charger on the Victron site. When looking at the 18 amp version, it can output as much as 25amp which means it would draw higher current than this. When testing my Renogy before wiring it in, I witnessed an output current no higher than 21 amps with a peak at startup at around 27 amps. Looks like there are quite a few settings on the Victron charger. Are you using custom settings or is there a selectable Lithium algorithm to handle the settings? Also it looks like the Victron uses screw terminals. Are you using ferrule's for these connections? If so what I've done to get a better connection when using these is to not use the crimping tool but to let the screw connection crimp the ferrule. This locks in the ferrule and provides a more robust connection IMO.

https://www.victronenergy.com/upload...50-400W-EN.pdf

Jim

[Guest]

John303 ,

I checked the output voltage at the 7 pin on my truck with the trailer disconnected. 12.35 static and 15.05 volts at startup where it settled in at 14.7 after a short period. GM is supposed to boost output voltage in tow haul but I didn't see this at idle where it could be tied to other triggers such as a connected trailer or RPM/Vehicle speed where additional cooling would be encountered.

Jim

[John303]

Guest

Thanks Jim. I will check voltages with the truck running which did not occur to me. After sleeping on it I think I am just seeing the real world effects of voltage drop and connectors. It surprised me that it was that much. I can see why people run separate charging lines with large wire.

[Guest]

@John303,

Once you get the voltage drop issue on the truck solved I hope you find success. You mentioned you did not change the trailer wiring where you may want to consider connecting the charge wire from the 7 pin directly to your charger input and nothing else. If not other items in the trailer may be pulling the voltage down on this circuit.

Jim

[John303]

Guest

Well, I took another crack at this in the afternoon. This time with the truck running I had 14 volts at the truck 7-pin. I would have thought I would have done that at some point, but apparently not; good thing I did not bet my paycheck.

So with the truck running, and the "smarts" effectively disabled, it charges. Input voltage drops to 8.6 and input current was around 22amps. As I watched it, the input amps slowly started to come down as you would expect. So the end result is a smart charger that I have dumbed down. It charges whenever hooked to the truck, which is really not that big of a deal for us since we never have the truck & trailer connected unless traveling. I wish I had bought the Renogy for less money, though. The only thing I really got was bluetooth connectivity to set parameters, turn on/off etc. Maybe that is worth something, but I had different expectations.

Thanks again for your help, Jim.

John

[John303]

Guest

Jim, one more question. You had mentioned using a ferrule on the stranded wires that connect to the Victron. I have never used ferrules before, and did not see any reference to them in Victron's documentation. Are you supposed to use a ferrule on this product? I just pushed the stranded wire in and tightened.

[Guest]

Guest

Jim, one more question. You had mentioned using a ferrule on the stranded wires that connect to the Victron. I have never used ferrules before, and did not see any reference to them in Victron's documentation. Are you supposed to use a ferrule on this product? I just pushed the stranded wire in and tightened.

John303

I noticed the Victron uses screw connections. With these connections a bare wire can be pushed to each side of the screw (depending on the design) and result in less contact with the wire. My Progressive Dynamics charger uses this type of connection where i noticed the slightest motion of the wire would loosen the connection. I bought a ferrule kit with crimpers, but what I found was it was best to install the ferrule on the wire and crimp it with the screw connection on the charger. This method dimpled the ferrule and resulted in a tight connection that could not work its way loose. Most likely resistance was also lower with this method.

The electrical guys here may also have additional information on the use of ferrules as well.

Below is a video that makes a good point in when to use ferrules.

https://www.youtube.com/watch?v=sMFFzpzKhFg

Here is an 8 AWG ferrule example.

https://www.amazon.com/Baomain-AWG-1...8264953&sr=8-7

Jim

[howson]

[USER="2239"]Below is a video that makes a good point in when to use ferrules. https://www.youtube.com/watch?v=sMFFzpzKhFg

Very informative video, Jim. CarAudioFabrication's channel has many videos that look like they are applicable to our "hobby"--looking forward to watching them. Thanks for the post!

[John303]

Guest

Time for an update after more experience with Orion-Tr Smart 12-12/18 charger. The key seems to be to set the low voltage deadlock lower than the observed voltage when the charger is running; in my case 8.6 volts. The function that checks for engine off works. When I turn off the truck the voltage drops to 12.6 volts which is detected as engine off, and charging stops. When the truck starts input voltage rises it is detected as engine on, and charging starts. It has some cycle where it checks every couple of minutes, so it detects it quickly. I have a higher opinion about it now, and I make use of the bluetooth data as far as input/output voltage. It draws around 22 amps from the truck, which is not that much for a 220amp alternator, so I do not think I will pursue wiring the running lights into the L-H pins. BTW, I think L-H means low and high, but not sure. The diagrams in the manual seem opposite from the text description, but not worth it for me to pursue further.

Thanks again for the help,
John

[Guest]

Guest

Time for an update after more experience with Orion-Tr Smart 12-12/18 charger. The key seems to be to set the low voltage deadlock lower than the observed voltage when the charger is running; in my case 8.6 volts. The function that checks for engine off works. When I turn off the truck the voltage drops to 12.6 volts which is detected as engine off, and charging stops. When the truck starts input voltage rises it is detected as engine on, and charging starts. It has some cycle where it checks every couple of minutes, so it detects it quickly. I have a higher opinion about it now, and I make use of the bluetooth data as far as input/output voltage. It draws around 22 amps from the truck, which is not that much for a 220amp alternator, so I do not think I will pursue wiring the running lights into the L-H pins. BTW, I think L-H means low and high, but not sure. The diagrams in the manual seem opposite from the text description, but not worth it for me to pursue further.

Thanks again for the help,
John

John303 ,

Very nice that you were able to get this running, and especially through the 7-pin connector. This just makes things so much easier to charge a Lithium battery over the road, with a reasonable input and with the ease of connection. Your correct where the L (low) pin is the battery negative and the H (high) pin is the battery positive which you could connect the marker lights to in order to force the charger on or off. I see the output voltage is also selectable in order to meet the specifications for whatever battery is used. Looks like this was a good choice in chargers with all the nice features.

Jim