Solar usefulness with lithium batteries

[booster]

This comes up fairly often in discussions and has changed some over the years, I think.

For us it was on the van and we really like having it, but I am unsure if I would spend a bunch to put it on. We have 300watts of solar, 618ah of lithium at 12v, and use 60-80ah a day most of the the time. If we get good sun we rarely need to charge with the alternator and we never plug in to shore power unless we need air conditioning.

You can check more than one of the options on this poll.

 

[GeorgeRad]

Not often mentioned benefit of solar panels if mounted correctly is temperature reduction in a van in direct Sun exposure. Sufficient air gap allowing for air circulation under PV panels will act as a tropical roof often used on vehicles in tropical climates. PV panels mounted without air gap or not allowing for air circulation will act like a black painted roof. My PV panels are mounte with approximate air gap of 1" to 2"

I didn’t vote as I don’t have Lithium batteries, but if I had them, with my minimalist attitude, I would want PV panels.

From AI answer to this question – what is tropical roof insulation vehicles air gap?

In tropical climates, proper roof insulation for buildings and vehicles relies on a combination of reflective barriers and air gaps to combat high solar radiation and heat transfer. Radiant barriers, such as aluminum foil, require a minimum air gap (typically 12–25mm or 0.5–1 inch) to function effectively, as direct contact with roofing materials leads to heat transfer via conduction.

 

[booster]

Not often mentioned benefit of solar panels if mounted correctly is temperature reduction in a van in direct Sun exposure. Sufficient air gap allowing for air circulation under PV panels will act as a tropical roof often used on vehicles in tropical climates. PV panels mounted without air gap or not allowing for air circulation will act like a black painted roof. My PV panels are mounte with approximate air gap of 1" to 2"

I didn’t vote as I don’t have Lithium batteries, but if I had them, with my minimalist attitude, I would want PV panels.

From AI answer to this question – what is tropical roof insulation vehicles air gap?

In tropical climates, proper roof insulation for buildings and vehicles relies on a combination of reflective barriers and air gaps to combat high solar radiation and heat transfer. Radiant barriers, such as aluminum foil, require a minimum air gap (typically 12–25mm or 0.5–1 inch) to function effectively, as direct contact with roofing materials leads to heat transfer via conduction.

Very true and nearly half of our roof is covered with panels so like being in the shade in that area. We do have gap.

With the solar panels, you would still get some reradiated heat off the bottom of the panels to the roof unless you have a reflective layer on the roof. I painted our roof with a very high reflectivity sparkle silver color and it cooled things down a lot over the whole roof.

 

[GeorgeRad]

I agree, white, light color or best reflective paint will help to reflect IR from the back side of PV panels. My van is a very light beige, not perfect but OK. Air circulation is critical, the worse are flex panels with no air gap glued directly to the roof.

 

[Sensfan-ClassB]

Adding solar that was not on the van could certainly be very beneficial. This acton would also introduce new risks, such as leaks or electrical problems. Van owners who are tech-savvy and able to repair these problems themselves assume much less repair cost risk than do van owners who are not

​

 

[Winston-ClassB]

Ten days camping in an open field at the Oshkosh EAA fly-in - - never moving the van, no shore power - - was a convincing example of the benefit of our roof-full of solar.

OSHKOSH Airshow Camping

Roof Full of Solar (930 watts)

 

[GeorgeRad]

Adding solar that was not on the van could certainly be very beneficial. This acton would also introduce new risks, such as leaks or electrical problems. Van owners who are tech-savvy and able to repair these problems themselves assume much less repair cost risk than do van owners who are not

​

It is possible to install PV panels with one penetration through the roof for a cable, I did that on my Sprinter van by utilizing roof rails to mount crossbars and panels.

 

[booster]

It is possible to install PV panels with one penetration through the roof for a cable, I did that on my Sprinter van by utilizing roof rails to mount crossbars and panels.

There are also a lot of Bs out there with glued on panels, although personally I would not do that.

Chevy Roadtreks allow you to do no roof penetrations if you are glued down panels, as the wiring can go in through the AC vents in the rear of the van so the penetration is in a dry area by the air conditioner. I did ours that way and it worked well.

 

[Sensfan-ClassB]

It is possible to install PV panels with one penetration through the roof for a cable, I did that on my Sprinter van by utilizing roof rails to mount crossbars and panels.

That’s a good looking setup.

 

[GeorgeRad]

There are also a lot of Bs out there with glued on panels, although personally I would not do that.

Chevy Roadtreks allow you to do no roof penetrations if you are glued down panels, as the wiring can go in through the AC vents in the rear of the van so the penetration is in a dry area by the air conditioner. I did ours that way and it worked well.

I had once panels mounted on fiberglass Bigfoot trailer with large footings and VHB tape, didn’t work. Perhaps if I sealed all edges it could work.

 

[Adagio]

For our rig & our style of travelling, solar does not make any sense. We have 15kW of lithium, no solar or generator. Batteries kept up by driving. We rarely stay in a single location for more then 5 days.

 

[RickNAmy]

This comes up fairly often in discussions and has changed some over the years, I think.

For us it was on the van and we really like having it, but I am unsure if I would spend a bunch to put it on. We have 300watts of solar, 618ah of lithium at 12v, and use 60-80ah a day most of the the time. If we get good sun we rarely need to charge with the alternator and we never plug in to shore power unless we need air conditioning.

You can check more than one of the options on this poll.

My Roadtrek 2004 210P had 4 100w panels installed when we purchased the van. I would not have installed them as we only camp full hook up. The panels do cover most of the roof so we do get the shading. My Isolater was acting up so I removed it as it was redundant with Solar. We ALWAYS have enough power to run the 12v side of the house.

 

[GeorgeRad]

For our rig & our style of travelling, solar does not make any sense. We have 15kW of lithium, no solar or generator. Batteries kept up by driving. We rarely stay in a single location for more then 5 days.

Great power, I don’t have 15kW appliances at home, what do you need 15kW for in an RV?

 

[Boxster1971]

Great power, I don’t have 15kW appliances at home, what do you need 15kW for in an RV?

It’s not 15kW, it is 15kWh (Kilowatt-hr). For example that would let you run 1,500 watt heater for 10 hours at 100% duty cycle. That size of battery lets me run my A/C overnight and still have 50% of battery left in the morning.

 

[GeorgeRad]

It’s not 15kW, it is 15kWh (Kilowatt-hr). For example that would let you run 1,500 watt heater for 10 hours at 100% duty cycle. That size of battery lets me run my A/C overnight and still have 50% of battery left in the morning.

Indeed, how the little letter h can transfer power to energy, just a little h.