diy solar

diy solar

Van - 12v, 14kwh lifepo4. Help needed for diagram review.

Also, considering my biggest load will be from my Victron charger/inverter Multiplus 12/3000/120-30
(12v 3000Va 120A charger)
1623502954861.png

1623502798669.png
and their recommendation for a 400A fuse, should I size each of my individual battery bank fuse at 100A ?
 
It’s generally acceptable to view ganged batteries as one battery. The charge controller feeds, direct loads, and inverter cables should be fused appropriately.
With the funny characteristics of electricity I think fusing between the batteries would become an ongoing regular expense.
 
Just as an aside, I also fitted a B2B (battery to battery charger) on my current motorhome which I've never done before. It's a Renogy 40A charger that connects from the vehicle battery to the battery bank switcher. I've also fitted a physical led switch which means I can start the vehicle, switch the Renogy ON and it will then put up to 40A as required per hour into whichever bank I want. I think the standard alternator on a 2006 Ducato is a 95A (which I can't presume would ever kick out that much) but I have measured the output from the Renogy and it does indeed put out 40A. If the banks ever needed a quick top-up a couple of hours driving would achieve this. This will be invaluable in autumn, winter and even spring when the solar just isn't enough to get a full charge back into my batteries. Lead acid batteries function much better (and longer) if you can keep them at maximum and not have them sitting around at 70% for days on end.
 
Hello :)

After a bit of progress on my electric diagram. I'm starting to build the structure for the batteries and the associated parts.

Before
The previous battery box was on left

76254



Now

76255



I'm trying to think of the best solution to house :
  • 4 packs of 4 cells (each cell weights 5.4kgs/12lbs) so a total of 87kgs/192lbs.
  • Multiplus converter/charger (Weight of 20kgs/45lbs)

I'm unfortunately short on time as I will only have a place to build it for a few days.
I have 8020 20mmx20mm extruded aluminium and I can buy wood locally.

1) Batteries on top of wheel arch.
  • 4 packs of 4 cells
  • Multiplus converter/charger vertically.

76257



2) Batteries on the floor
  • 4 packs of 4 cells
  • Multiplus converter/charger horizontally


76258


3) Batteries on the floor
  • 16 cells in a row
  • Multiplus converter/charger flipped
1626718173921.png


I also need to fit the BMS, wires, existing equipment, fuse holder, switch and miscellaneous.

Do you have any ideas of what would be the best in terms of load/space saving?
 
Last edited:
I'd be weary of not having the batteries on the floor as in number 1). I'm using 8S 280Ah, that's already >40kg.

I know it looks neat but when you're driving along, it seems like it's gonna be huge force applied to the structure when you go over bad bumps in the road.
 
Hello everyone :)

I've lived in the van full time since a few months now.
I would like to improve the electrical enclosure. I was a bit in a hurry last summer so I was only able to put one battery. It was my first time working with 8020 also.

Now, time to build v2.
I've got enough extruded aluminum and more tools and knowledge.

Below are a few pictures of v1.
1648227408476.png1648227601457.png

I bought 16 cells but could only fit 4 in a rush.

I would like to try to put as many cells as possible this time while still trying to maximize the cargo space.

The bed height can be adjusted.
Ideally, the picture below would be it's optimum position.
1648228801186.jpeg

If I managed to reduce the height of the electrical enclosure I would maybe even be able to put a box like below on top of it.

1648228902407.jpeg
 
For the electrical update. It's a 12v system, 272AH cells. 150AH JBD BMS

I'm planning to either put 3 battery pack or 4. Considering the space available.

The charger/inverter is a Multiplus II (12v 3000Va 120A charger)

1623502954861.png


1623502798669.png


Victron's spec recommends a 400A fuse.

Reading a few topics about fusing and parallel battery pack, I think the consensus seems to be fusing each battery pack with a class T fuse.

If I understood properly, fuse are there to protect the wires.

At the moment I'm getting lost between the apparent power, real power, power factor. VA and Watts to properly size the fuse for each battery pack.
Should I take into account the peak power of the inverter also? 5500W?
 
Back
Top