DC-DC charger current limiting

[RyG]

Oh yeah, when running the unit at max power (circa 18A charging current), pin 4 on the 7 way connector drops to a pretty low voltage (below 10V if i remember correctly, with a 14V alternator voltage), which amongst other things, causes problems with the brake controller. I'm also not too excited about dissipating upwards of 100W along the length of the cable that feeds the trailer connector on the tow vehicle.
So for now, I've got the Victron app open on my phone and slowly increase the voltage as we're driving down the road.

 

[Short_Shot]

Given the voltage drop it may artificially limit current when hooked straight to lithium though.

Whenever mine shows up I'm going to put a 15a fuse in my truck and see if it survives. If not, I'll just disconnect the power wire in my camper and rely on my solar entirely.

If you have brakes which need battery power in the trailer a small 50w solar panel and cheap pwm will keep it full year round, so long as you don't have a ton of parasitic draw.

Right now it has a factory 40a on what looks like 14 gauge wire.

 

[RyG]

Given the voltage drop it may artificially limit current when hooked straight to lithium though.

Whenever mine shows up I'm going to put a 15a fuse in my truck and see if it survives. If not, I'll just disconnect the power wire in my camper and rely on my solar entirely.

If you have brakes which need battery power in the trailer a small 50w solar panel and cheap pwm will keep it full year round, so long as you don't have a ton of parasitic draw.

Right now it has a factory 40a on what looks like 14 gauge wire.

Yes, similar on my tow vehicle. Think it's a 30amp fuse on 14 gauge wire...
My TT has a 12V compressor fridge, which draws roughly 80W when the compressor is running. I have solar, but after a couple of days of overcast weather, I need to top the LiFePO4 battery up with the alternator.

 

[Short_Shot]

Yes, similar on my tow vehicle. Think it's a 30amp fuse on 14 gauge wire...
My TT has a 12V compressor fridge, which draws roughly 80W when the compressor is running. I have solar, but after a couple of days of overcast weather, I need to top the LiFePO4 battery up with the alternator.

More solar obviously.

My iceco pulls 60w and I have the same issue with 150w. It barely meets my needs on a sunny day. Unfortunately at this time I don't have the space to run more on my baby teardrop.

But my solution is to get a 280ah pack and it'll last a whole weekend easy lol

 

[sunrise]

Hey all, OP here, great to see all the comments in this thread. I think waiting for Victron for a software update doesn't seem to be a viable option, as the hardware might not have such capability.
I have just purchased 1 step down converter and 1 boost converter from aliexpress, both have adjustable output current limiting functionality. I plan to connect them(need to figure out which one works better) in series with the DC-DC charger. They are fairly cheap, 2 for less than $20, shipping included.
I will start on this as soon as camping season in PNW ends, but for now I will enjoy the weather and outdoor first. I will report back my findings.

 

[JeffK]

It's been quite a while, but I have the same problem. Did your solution work?