Victron Energy & BattleBorn Install - Solitude 3540GK

[dagerlach]

Last year I installed the basic 1000 watt WFCO inverter system for the season. It worked great....but I wanted to switch to Victron electrical and BattleBorn batteries. Thus, my new early spring science project began with ordering all my new parts this week.

One part I have held off buying, because of mixed reviews/comments, has been the dc/dc converter.

I have a dual alternator 2022 GMC Sierra HD AT4 Duramax. Has anyone towed without using a dc/dc converter when running LiFePo4 batteries? I haven't been convinced of its need yet. Anyone with real first hand experience?

Thanks,

David

[JKellerJr]

Last year I installed the basic 1000 watt WFCO inverter system for the season. It worked great....but I wanted to switch to Victron electrical and BattleBorn batteries. Thus, my new early spring science project began with ordering all my new parts this week.

One part I have held off buying, because of mixed reviews/comments, has been the dc/dc converter.

I have a dual alternator 2022 GMC Sierra HD AT4 Duramax. Has anyone towed without using a dc/dc converter when running LiFePo4 batteries? I haven't been convinced of its need yet. Anyone with real first hand experience?

Thanks,

David

I have never used one. Running BB lithiums since 2017.

[JKellerJr]

Unless you have the need to charge the RV with more than the 6 or 7 amps the truck puts out there is no need.

[Hoopy Frood]

Unless you have the need to charge the RV with more than the 6 or 7 amps the truck puts out there is no need.

Depending on the brand of truck, 6 or 7 amp draw from the truck could be optimistic. Considering the size of the wires, it could be closer to 3 or 4. Or so I've been told.

[JKellerJr]

Depending on the brand of truck, 6 or 7 amp draw from the truck could be optimistic. Considering the size of the wires, it could be closer to 3 or 4. Or so I've been told.

True. It really depends on the situation. If you want to use the truck as a charging source then you need one. Otherwise I think it’s a waste.

[SolarPoweredRV]

Last year I installed the basic 1000 watt WFCO inverter system for the season. It worked great....but I wanted to switch to Victron electrical and BattleBorn batteries. Thus, my new early spring science project began with ordering all my new parts this week.

One part I have held off buying, because of mixed reviews/comments, has been the dc/dc converter.

I have a dual alternator 2022 GMC Sierra HD AT4 Duramax. Has anyone towed without using a dc/dc converter when running LiFePo4 batteries? I haven't been convinced of its need yet. Anyone with real first hand experience?

Thanks,

David

Having a DC-DC Converter will depend entirely on how you intend to use your camper and how you intend to keep the batteries charged.

Here is how I addressed the DC-DC Converter issue...

First, I have a large battery bank (800ah), there is no way my Tow Vehicle could add any appreciable charge to that battery bank even if we are driving for 10 hours, consequently, I disconnected the charge cable from the 7-pin plug.

Second, I have a large Solar array on the roof (1,200 Watts). When I am driving down the highway, my roof receives full Sun all day long, unless it is cloudy, but even then my Solar panels are still pumping electrons into my battery.

I designed my system to be charged primarily by the Sun and it has worked out well. If I hit a few cloudy days, that is why my battery bank is so large. I will give you an example: early Spring of 2020, my wife and I traveled from Phoenix to Florida mostly on Sunshine (for the coach, the truck drank plenty of Dino Juice). Before we left Phoenix, we had been boondocking for 5 or more days, so we didn't "charge up" before we left. We traveled for about 8 days before we stopped in Mississippi and plugged into shore power. That is about 2 weeks between shore power connections. During that time, I never really worried about having enough energy in the batteries. We never got quite full each day, but, for the most part, we replaced 90% (+/-) of what we used every night.

However, more recently, on some of our shorter trips in the hot South, I have run down the batteries more than I was comfortable with by running the Air Conditioner during our lunch breaks. This has caused me to reevaluate the DC-DC Converter issue.

When you are looking at a DC-DC Converter, you need to ensure that the Converter will make an appreciable contribution to your batteries. Take the number of hours you normally drive and multiply that number by the amps output of your DC-DC Converter. I.e.: I was looking at a 15 amp Converter, which, if I drove 10 hours, would add ~150ah to my 800ah battery bank, not a small amount, but not enough to make much difference in an 800ah battery bank either. Consequently, I chose a 40amp DC-DC Converter, which would theoretically give me 400ah in a 10 hour drive. Now, that is a real contribution to my energy storage.

So, I have traveled without and soon to be, with a DC-DC Converter. All I can say is that as your needs change, you may need to adapt your system.

PS: because of the potential for alternator damage, I do not recommend charging Lithium batteries direct from the Tow Vehicle, disconnect your 7-pin wire or remove the trailer charging fuse from the Tow Vehicle.

PPS: I have a 24v battery system in my couch, consequently, I did not actually install a 40 amp DC-DC Converter, I installed a 20 amp, up voltage, 12v to 24v DC-DC Converter which yields 40 amps at 12v DC equivalent, that is how I can get 400 amps of charging in a 10 hour drive.

PPPS: I don't anticipate using my DC-DC Converter very often, but it is nice to have it available.

[Jomani]

Like @SolarPoweredRV said, it all depends on how you plan to camp. While I haven’t actually installed mine yet, I have a 60amp Renogy ready to go. My ultimate goal is as follows:

Sticking with the factory 165w solar (at least for now) so I felt the need for a secondary charging source. Currently running a single 200 ah LiFePo4 but will eventually add at least another 200 ah. We don’t typically boon dock, but want to have the ability if needed. With the DC - DC Charger, we can stop for lunch, open the living area slides and and have access to microwave, coffee pot, air fryer, etc. , then close everything up and travel to our final destination. If that happens to be a Harvest Host site without power, we will arrive with fully charged battery(s) and be able to setup, cook dinner, watch TV, etc. I rely heavily on a CPAP machine, so I also need a reliable power source for that.

My Ram also has dual alternators providing 440 amps. I plan to use the auxiliary switches to both power the charger through a relay, and control the output (only run the charger at 30 amps unless I need the extra output). I have read a lot about the 7 pin charging circuit, and have decided to remove it. I will probably use it to power the running lights on the 5th wheel - I think that will solve the problems I am having with the Furrion backup camera, then possibly use the running light circuit from the 7 pin to drop the output of the DC-DC charger. That way, when traveling at night, the max output of the charger is 30 amps.

Again, no real world experience, but lot’s of research.