Isuzu npr 4wd

[gator70]

Time to do a health check and analyze the solar panel engineering on the roof.

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☀️ Solar Array Setup (Mixed Panel Sizes)

🔹 Array A: 4 Larger Panels

• Panel model: GXNY-6M-240
• Specs per panel:
  • Max Power: 240W
  • Best Working Voltage: 18V
  • Best Working Current: 13.4A

🔧 Wiring: Series

• Voltage (V) = 18V × 4 = 72V
• Current (A) = 13.4A
• Total Power = 240W × 4 = 960W

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🔸 Array B: 2 Smaller Panels

• Panel model: GXNY-6M-120
• Specs per panel:
  • Max Power: 120W
  • Best Working Voltage: 18.4V
  • Best Working Current: 6.60A

🔧 Wiring: Series

• Voltage (V) = 18.4V × 2 = 36.8V
• Current (A) = 6.60A
• Total Power = 120W × 2 = 240W

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⚡ Wiring Recommendation (for Mixed Panel Arrays)

✅ Best Approach:

Keep arrays separate and connect to a dual-input MPPT charge controller or two separate MPPT controllers.

Why:

• The arrays differ in both size and output (voltage/current).
• Connecting them together would limit power generation, as mismatched voltages in parallel are unsafe and inefficient.
• Dual MPPTs allow each array to operate at its own peak efficiency.

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📊 Combined System Output Potential:

Array​	Voltage​	Current​	Power​
A (Large Panels)	72V	13.4A	960W
B (Smaller Panels)	36.8V	6.60A	240W
Total	—	—	~1200W

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🧰 Optional Setup: Common Battery Bank

• You can wire both MPPT charge controllers to charge the same battery bank, as long as the charging voltage settings match (e.g., 12V, 24V, or 48V system).
• This lets you harvest full energy from both arrays without forcing mismatched wiring.

 

[gator70]

In Oz, I use MDPE rotomoulded DIY tanks for diesel, legally. For Petrol they need to be cross linked HDPE which is much more difficult and expensive.
Cheers,
Peter
OKA196 motorhome

I found a NEW 1984 Chev Blazer fuel tank of 25 gallons that fit nicely between the frame rails on the Isuzu NPR. About center to the wheelbase.

The stock fuel tank is behind the rear axle and is 30 gallons.

This way I can never overfill the stock tank with the transfer pump, As long as the fuel gauge shows empty.

 

[gator70]

Folks complain about the huge cost of Expedition vehicles, yet many do not realize all the parts, labor and engineering that is part of the build.

 

[gator70]

Front bumpers - bull bars for the isuzu npr 4wd are about $3000 in Australia

I need a front bumper and winch tray

I look at this one, cutting it in half and sectioning 5 inches out of the center. I need a width of 81-82 Inches about.

Then welding it to a heavy duty winch tray, and fabricating bumper brackets

 

[SkiFreak]

This way I can never overfill the stock tank with the transfer pump, As long as the fuel gauge shows empty.

Good in theory, but I have seen examples where people simply forget to check.
If you are happy with that setup, then use it. Personally, I don't trust myself.

 

[gator70]

Why I decided not to build on this platform

I hate air systems and they can cause breakdowns
Requires bigger tires and more weight capacity
Platform has very old wiring looms and hydraulics, even if the mileage is low
Too many technical issues to breakdown such as tire inflation system
No air conditioning and electric windows standard
Interior feels military
Cab does not seat enough people
Spare tire behind cab
Not California DMV friendly

 

[SkiFreak]

Why I decided not to build on this platform

We all make decisions based on what we believe to be the right reasons, be that right or wrong.

 

[gator70]

Not bad, I'm interested

 

[Ferjablito]

As my colleagues told you, if you are going to modify it, I don't see the advantage, considering that the material is not the most expensive if you know how to weld, I don't understand why not to do it to your exact measurement in 3mm minimum.

 

[gator70]

As my colleagues told you, if you are going to modify it, I don't see the advantage, considering that the material is not the most expensive if you know how to weld, I don't understand why not to do it to your exact measurement in 3mm minimum.

The above are new not modified. Available for purchase just recently

A few months ago I bought aluminum rear fenders and I would need to fabricate mounts for theses. Using theses storage boxes, and the mounts for these I could integrate the rear fender mounts and save money by one set of mounts.

As far as the length, they work

 

[Ferjablito]

sorry, I misread you

 

[gator70]

Everything you do with a expedition vehicle has a compromise.

The platform I chose was based on super single options, total weight capacity, not too much not too little. Along with turning radius and on frame length. Even total height, based on subframe and mounting height, with the obstacle of a very tall cab and a queen bed over the cab.

Each one of these decision has a positive and negative angle to the results.

Even the interior, has a oversize shower - toilet, an oversize dinette, and less space for other items. Looking back on those decisions, they have a positive and negative angle to the results.

 

[gator70]

Just discovered the supplier did not follow my instructions on solar panel wiring. When I ordered two seperate mppt controllers it was very confusing for them. And they installed the second one in a location on a circuit with no panels. While running two unmatched arrays through one mppt controller, and the results is a 25% loss of efficiency with my 1200 watt capacity.

This can be fixed without a major issue. Yet it is hard for me to understand solar panel wiring is not understood by everyone.

 

[gator70]

I ordered extra large two burner propane stove so I can use larger pans, due to the burner separation. And larger sink so washing large items is easier. The compromise there was counter space. Like most rigs I have a fold up counter extension on one side.

Yet I felt a cutting board was missing.

I noticed the top drawer, was a bit extra deep, and so today I cut a bamboo cutting board, removable to place on top of the drawer box side walls. With still space underneath for utensils. So closing the drawer all fits nicely, and when the drawer is open I have my cutting board.

 

[SkiFreak]

Many kitchen setups, including my own, incorporate a cutting board that is inset with the sink.
When not in use this gives you more usable benchtop space and when needed, it is easily accessible.