Solar & Battery upgrade priority (also improvements also) - advice?🙏

[Refresh]

Hi there forum,

I am looking to thoroughly upgrade exterior, and refresh the interior, of my Sprinter T1N, Class B, motorhome. Once the Corona restrictions lift we want to move on in an effectively new 'home'

WE are working on various upgrades ($$ allowing)
The most important issue is installing the most potent solar & battery system we can.

Any advice you can all offer would be EXCEEDINGLY WELCOME and appreciated:


What is the highest potential solar and battery storage (Lithium) one could fit onto a Sprinter T1N?


I wish to use Lithium batteries instead of AGM.
Unless you all advise strongly against that.

The 2 batteries can weigh a maximum 100kg in total.
They must provide a, total, capacity of 550AH minimum

I already have a solidly crafted metal battery storage box in place just behind the rear axle.
I can store two batteries of 51cm x 27cm x 22cm


Though I am also considering the use of additional foldable & flexible solar panels, I first, need to install the maximum wattage/12v Amperage on the roof.

What would be the best system anyone has experience with and can, confidently, recommend.

Is 45AH produced, in full desert blasting mid-day sun, a realistic aim?

My thanks, in advance, for any advice you all can offer me.🙏


Refresh

PS. Roof dimensions, top-down, attached

[KDB]

If you'll be in cold weather Lithium is not traditionally advised. Your battery compartment sounds like it could be in a spot of exposure.

[Klompen]

My AGM battery is under my Sprinter and I live at 7,000 feet where it gets cold. I have discussed this with Battleborn and have been assured that their batteries can live quite well in my location when used in cold weather. Cold does not affect discharge of LPO4 batteries and BB's battery management system prevents them from charging if it is too cold. It doesn't take much driving to warm up the batteries enough to start charging.

[Klompen]

I would highly recommend that you check out RV Solar - I'm Not Lost I'm RVing

[1der]

Originally Posted by Klompen

.......Cold does not affect discharge of LPO4 batteries and BB's battery management system prevents them from charging if it is too cold. It doesn't take much driving to warm up the batteries enough to start charging.

How does driving warm up the batteries mounted outside under the van if they cannot accept a charge because they are too cold ? Are they mounting them next to the exhaust pipe?? What is the windchilled temperature below the van while moving at 60mph and an air temp of 20F?

And if the batteries are below 24F, Battle Born's low temp cut off, even though the solar panels are outputting , it does nothing to heat the batteries, so the BMS will prevent the batteries from receiving a charge from the solar controller, right?

And while discussing temperatures for charging Li batteries and you mention "Full Desert sun" - 135F is max temp for Li charging. That can easily be reached in desert sun hitting black top.

[1der]

an excellent thread on topic w a truly excellent recap by Scalf77 and a post by hein as to what they do to mount below floor.

https://www.sportsmobileforum.com/fo...ene-25017.html

[boywonder]

Originally Posted by Refresh

Is 45AH produced, in full desert blasting mid-day sun, a realistic aim?

The panels will be producing amps....over time you'll accumulate amp hours.


If you mount a pair of 360W house style panels as an example.....you'll have 720W. 720W/12V=60 amps.....on paper under laboratory conditions in cold weather with blazing sun directly overhead. Realistically you'll see 75-80% of this in real life conditions (rough estimate)...so 45 amps or so...


Also keep in mind that's high noon with the sun directly overhead. When the sun is rising and setting the solar output is much less. Portable panels do a good job when the sun isn't directly overhead since you can move them around and keep them pointed at the sun.


Most RV style solar controllers are rated at 30 amps, but there are plenty of controllers that are rated higher....Midnight Solar is one manufacturer that make higher current rated controllers.


Also, you may already know this, but if you use a PWM controller you need to stick to 12V rated panels which output around 17V max. MPPT controllers are a bit more efficient and can use any voltage panel. Residential house style panels output around 36V or more max voltage. Since you are talking Lithium and want max performance we'll assume you want an MPPT controller.