Why did My 7 Way Melt While Using Curt Echo and My Orion TR to Charge My Lithium Batteries?  

Note: Semi Copy/Paste From My Post in Victron Facebook Group I have a basic tear-style camper with two 100Ah Battleborn LiPo batteries. Last May, I installed an Orion TR Smart 12/12 18 Isolated into the camper. This was done primarily to prevent the batteries from backfeeding into the tow vehicle. I intentionally chose the 18-amp version as I mainly wanted it for the protection factor, with charging being a plus. I didnt want to have to worry about wiring up a second wire to the battery and wanted to use the 7-pin, as we have two tow vehicles*, and this would be not only expensive, but tedious to do for both vehicles. As an extension to this, I originally bought the Curt Echo Brake Controller so I could have a brake controller that was easy to swap between vehicles, again without the expense and difficulties of installing a brake controller in both tow vehicles. This setup has worked well, and weve gone on multiple trips where we were driving for over 6+ hours, with less than an hour of stops. Last month, we went on a semi-local trip where we were boondocking. When we woke up in the morning, I realized that the batteries were low and I feared they might not last the night. I decided to hook up the vehicle and let it sit for ~ 30 minutes to let the batteries charge a little. I had left the brake controller plugged into the camper, so I didnt remove it from the 7-pin when I did this. When I went to unhook the trailer, I found that I couldnt remove the brake controller from the vehicle. After fighting with it, I finally got it out, but it pulled the pin out of the tow vehicle because the brake controllers plastic around the pin had melted, locking the pin in place. Now, not only do I have to replace the 7-pin housing, but I have to replace the brake controller as well. My first question is if there are any thoughts on how/why this might have occurred. My understanding is that my TR is rated at 18 Amps, while the brake controller is rated at 30 Amps, so in theory, this shouldnt have happened. Taking it a step further, driving 6+ hours with no issues vs 30-minutes seems very odd to me. While I suspect part of it has to do with the state of charge of then vs now, it still seems odd to me. Honestly, I would have expected it to blow a fuse first, before getting so hot it melts. My second question is if the TK94FR would be better than the Curt Echo Brake Controller. It comes at much higher a cost, so I am looking for the most cost-effect way to get back up and running. Additionally, I worry about the same thing occurring again. I want to make sure that the TK94FR can handle the voltage and amperage of what should have otherwise been a simple charge. Our camper is an off-road trailer. When we go overlanding/off-roading, we tow using our Jeep. When we are not going off-roading, and just using the camper as an RV, we instead tow using our Tacoma since it gets better millage and is a better comfort ride. I want to be able to swap between vehicles without having to go through the extra expense of full wiring a separate line for charging or full wiring the brake controller in both vehicles. Additional Question on Victron Page My additional question is that my research has led me to the new Orion XS. Im questioning if it might be smart for me to upgrade my TR with an XS. The brief research Ive done makes me feel like the XS is near tailor made for my use-cases. In theory, I can easily configure the XS to a lower amp input, thus still charging, but also not getting so hot as to melt the brake controller again.

asked by: Charles M