Max Roof Load for Van Stability

[TheMobileWanderer]

Any mathematicians here?

OK, so I'll be having 100Ah at 48V, which means 4800Wh. (possibly 200Ah = 9600Wh).
I don't ever want to need EHU or to run out of electricity and I'm thinking a fixed cost of solar installation would be better than continual EHU costs.

From a dimensions perspective; I can fit the following solar panels, if I cover the whole roof, where there are no skylights and fans.

1. 4 x 300W = 1200W ( 61.6kgs total)
2. 8 x 100W = 800W ( 48kgs total)

A total weight of 110kgs (excl fixings) giving 2000W solar power, which 'should' recharge the batteries fully from empty in 2.4hrs. (Thinking: that should enable full/substantial recharge over the usual calculation of 5hrs, if sun not shining/constant).

GVW of van will be 7.5T
Fresh tank will be 250L capacity and there will be batteries, heating, other weights in the subfloor, which, I wonder, might compensate/counteract the roof weight.

So, after all that, my question is what do you suggest might be the max sensible weight of all roof content, including skylights, fans and panels, to minimaise a feeling of top-heaviness when going around corners?

 

[Raul]

Don't know exact answer to max weight, but, builders vans have roof racks.
I had a rack capable of 250kg, and often carried many roofing battens, 5-6 bundles at times. The roof will transfer the load on to lateral walls. So if you have solid walls, and solid structure to take the panels you can even have a double decker.

As battery side, 9kwh is not allot. Skip the 100-200Ah and go straight to 300Ah at 48V.
We currently have 8.96kwh and we can go trough it in grim days.

 

[Jev88]

Just seen an RV with 2400watts of solar!

So as you are already heavy it shouldn't matter.

 

[funflair]

It really all depends on how you want to use your van and how reliant you want to be on 240v electric from batteries, even 2000watts of solar is not a lot of use in the middle of winter with cloudy grey sky for days on end so that is when you need battery capacity, if you intend to be a heavy 240v user for a week or more at a time I would max the batteries to at least the 9600Wh and personally I think I would be happy with the 1200W of solar, if you really need more than that in the winter just stand a couple of panels facing the sun and you can leave them at home in the other seasons.

Again depending where you are going to be stopping and for how long I might be tempted to go for more than 250 litres of fresh.

 

[TheMobileWanderer]

It really all depends on how you want to use your van and how reliant you want to be on 240v electric from batteries, even 2000watts of solar is not a lot of use in the middle of winter with cloudy grey sky for days on end so that is when you need battery capacity, if you intend to be a heavy 240v user for a week or more at a time I would max the batteries to at least the 9600Wh and personally I think I would be happy with the 1200W of solar, if you really need more than that in the winter just stand a couple of panels facing the sun and you can leave them at home in the other seasons.

Again depending where you are going to be stopping and for how long I might be tempted to go for more than 250 litres of fresh.

Thanks all.
I agree 9600W isn't enough. I think I considered just the 100Ah when I moved from 12V to 48V and it was of similar capacity to 400Ah on 12V. I've since upped my cooking equipment requirements.

Good shout funflair, regarding the fresh tank size.
I've yet to fine-tune the spec for the plumbing system. That's further down my list, when I get the shower room and kitchen planning completed.

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[KNWH]

Out of interest I just Googled ‘height of centre of gravity in a Motorhome’ and got this AI generated gem:
The height of the center of gravity (CG) in a motorhome is generally lower than its overall height.
I would really like to know under what circumstances the height could be greater than the overall height
AI has still got a way to go

 

[BouncyBoatFolk]

Buses come in double decker versions.
Mike.