Solar question around charging from Tow Vehicle and Trailer Converter

[Projectman]

I own a 2018 Heartland Mallard 185. I have installed a battery box on the trailer tongue and in the box I installed a LiFePO2 Lithium 100AH battery, a battery disconnect switch and a 75V/15A MPPT controller. I have a Renogy 100W suitcase solar panel and will have it connected to the Trailer’s Furion 10A connector.

I have been told the Mallard won’t charge the battery when it is connected to a 30A campground power pole as the lithium battery voltage will be too high and the converter won’t send a charge to it. Will I need to buy a new converter for the trailer specifically designed to charge lithium batteries?

Also, I have been told my 2017 Chevy Tahoe may/will have issues charging a lithium battery without a DC-DC converter and perhaps a larger alternator. Do I need anything for the Tahoe considering I only have one lithium battery?

A couple of other questions. Will I get good performance using the furion connector when Boondocking since it has to run to the converter and back out to the battery or should I connect the solar panel directly to the controller? The most convenient way is using thenFurion connector and I realize I may lose some power with it connected this way? Thoughts?

I’m preparing to go on a trip (May 15th) with a buddy of mine from Florida to CO, UT, ID, OR, WA, WY, SD, and then back home and we plan on Boondocking most of the time for 2-4 days at a time. I will run the fridge off propane and won’t run the heater unless the indoor temperature reaches 55 degrees.

Obviously we will need sun for part of the time when we boondock and will carry a Honda 2000W generator to charge the batteries if needed. Total trip will be 2-3 months.

Do I need a new converter to charge the lithium battery when connected to campground power and do I need anything for the Tahoe. I have already spent quite a bit of money getting the solar and other equipment for the trip so not forward to spend a lot more money.

I look forward to anyone’s thoughts that has knowledge in this area. Thanks in advance for your help.

 

[centerline]

first, I wouldnt buy a different converter, but just buy a battery charger for the lithium batteries....

second, the pickup charges a battery so minimally that its isnt worth the cost of messing with it.... the size of the alternator makes no difference.
the positive wire to the terailer from the tow vehicle is no larger than a 10ga wire, but more likely a 12 or 14 gauge, and for that distance and the number of connections in the run, on a good day you will only see about 2 amps going to the battery from the tow vehicle... yes, its better than nothing, but if you were to drive for 10 hours, you could get possibly 20-25 amps in the battery... why? because in the long run of the circuit, the voltage drop during that distance prevents the battery from getting the force needed (due to the lower voltage) to push the amps into it...

third, I dont understand the "furion connecter" term or what it does... but with the multiple charge sources you may have, they can ALL be connected to the system at the same time, and in the same spot. some people think the solar panels need to be disconnected when tied in to shore power, but this not true....

all the charge sources will "see" each other, and the strongest charge source will be the dominant one, and so the others will shut down to float while the dominant charger takes care of things..
when that charger gets taken off line, shut off or unplugged, the next most powerful charger in the system will take over... during boondocking when the generator isnt running, the solar is doing all the work..... which is why a hard wired solar array is such a nice system to have. build and install, it and forget it...

 

[Oregon_Camper]

I have been told the Mallard won’t charge the battery when it is connected to a 30A campground power pole as the lithium battery voltage will be too high and the converter won’t send a charge to it. Will I need to buy a new converter for the trailer specifically designed to charge lithium batteries?

Find the converter and Google the model number. It might be new enough to have a Lithium profile. If not, it will charge your battery, but only to about 85%.

A couple of other questions. Will I get good performance using the furion connector when Boondocking since it has to run to the converter and back out to the battery or should I connect the solar panel directly to the controller? The most convenient way is using the Furion connector and I realize I may lose some power with it connected this way? Thoughts?

The Furion connector should not be connected to the converter. Only 110v power is sent "to" the converter. From there, the converter will provide 12v to the RV and charge battery.

You said you are buying a 75/15 MPPT solar controller. Will you remove the controller (most likely PWM) on the 100w suitcase solar? Your best solution is from 100w panel....to 75/15 MPPT....to battery. If you had a larger solar array...say 1000+ watts, then I'd have a conversation about wire gauge, but your 100w panel, at best, will only be producing around 4.5 amps.

 

[centerline]

Find the converter and Google the model number. It might be new enough to have a Lithium profile. If not, it will charge your battery, but only to about 85%.

You said you are buying a 75/15 MPPT solar controller. Will you remove the controller (most likely PWM) on the 100w suitcase solar? Your best solution is from 100w panel....to 75/15 MPPT....to battery. If you had a larger solar array...say 1000+ watts, then I'd have a conversation about wire gauge, but your 100w panel, at best, will only be producing around 4.5 amps.

I strongly agree... too many people think the panels will output what they are rated at, but in actual use, they will average an output of about 50% of their rating. some days more, some days less.
as for the wire from the panel to the controller (which should be installed near the batteries) you do want the wiring to be rated at least for the rating of the panel, or preferably even more, so that when you decide to add more panels (which you most likely will), you wont have to re-run new wires.... and yes, always use an MPPT controller for the best performance...

 

[RonnieB23]

Since we are talking about multiple power sources with Solar included, has anyone had experience using an In-Vehicle BCDC battery charger? I have an F250 Diesel with a variable output alternator (upgrade). Instead of 2amps, with the BCDC it can produce much higher amperage output to the trailer (40amps continuous) while driving. Provides connections to solar as well which can (as CenterLine identified above) "see" each other. I have a Landmark Syracuse 5th wheel with residential refer. We many times stop in Highway Safety Rest Stops overnight on the way to our destination. When it is hot out, the 200amp batteries are out of power by 4am without using fans or other devices (I do not have solar, yet and yes it can get quite warm inside). Doesn't feel right breaking out the portable 3500w generator (don't want it 'missing' in the morning). Firing up the truck, I can get them back on-line at the next stop. Obviously Lithium batteries would help with this issue, but I would also need to replace the charge controller (not compatible with lithium's higher volt requirements on auto, could limp on manual). So quite a large expense. This also adds the ability to add solar down the line. Reason: Wife retiring and with the ability to WFH, anywhere can be my office.