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Premium Member
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Discussion Starter · #1 ·
Hi - running a Thanksgiving weekend sale on the 1 kW class drop in power systems that we build.

Must be a promaster forum member.

This offering is for the "1 x 1 (TM) Power system.

The details are in the description, but it is a ruggedized / suitcase size power system in a case.

Power inputs / charging from:
  • solar panels
  • 120 vac
  • 12 volt vehicle power input.

All built in.

Power outputs for:
  • 120 vac (10 amps)
  • USB
  • 24 volt (unregulated)
  • 12 volt regulated via the 12 volt distribution panel.


This model is particular good for applications where the van will be used in cold weather. It is one of the most robust, 1 kW class van electrical setup around for cold or hot weather use.

It will power 12 volt heaters and refrigerators under conditions where many other systems will fail. Far beyond the temperature range of a typical retail type power system / solar generator.

Regulated 12 volt output means that you don't have to worry about too high of voltage for your exhaust fan, or too low of voltage for the heater or refrigerator

Can also be used to power critical loads in a home, such as a furnace or refrigerator when the power is out.


Sale runs from now until midnight Sunday night, 2021 November 28.

20% off of this line item.

Contact me via private messaging for a discount code



Harry N

Premium Member
1,439 Posts
Discussion Starter · #2 · (Edited)
N, I looked at your 1x1 system & have a few questions. What is the charging rate of the 12v "cigarette lighter" socket? What is the output of the included solar panel? If you add 12v branch lines (Frige, furnace, etc) then the 1x1 is not readily portable, is it.? Or are there plugs on the outside of the case beside the USBs & 12v duplex? Do the 2 not included batteries fit inside the case? One photo show a pic of some wiring in a 12" box. Is that box inside the bigger case? What do the colored boxes in some pics represent? How do customers move them and secure them in a van? What are the customer demographic? Thank you.

Thank you for your interest and the questions.

Solar Charge related:
  • The solar panel is not included - it is just shown for reference.
  • That panel is ~ 59 x 26 inch and is ~ 150 watts. I tend to use solarland panels but any brand can work.
  • The built in solar charge controller will limit the total power coming in to 550 watts. If more "actual power" is available, then it well self limit.
  • For this area, in order to achieve 550 watts at the peak of the day would require approximately 800 watts of panel directly facing the sun on a very bright day
  • Right now I have one of these systems powering my off grid shop. With 450 watts of solar and this time of year, it peaks out at ~ 150 - 200 watts.

Solar panels:
- You can use any solar panel or solar panel array with a nameplate Vmp between 30 and 40 volts.

At my shop, I have the following mix of panels hooked up to it
  • 1 each, poly panel, 140 watt solarland, 24 volt style, Vmp ~ 36 volts
  • 2 each, mono panels, 160 watt, solarland, 12 volt style, Vmp (each) ~ 18 volts. The two wired in series are ~ 36 volts
These two "arrays" are each plugged into the system individually and these feed the 1x1 system.

I could easily have 2x this attached if I had the panels.

Since this system has a relatively modest battery pack size, it cannot store enough power to average out over a week of use in overcast conditions. For that reason, I suggest that a van owner with this setup actually have a fairly substantial array - at least 400 watts - ideally more like 600 watts if there is room.

  • The 2 each, customer supplied AGM batteries fit inside the case.
  • Each of these weighs ~ 50 lbs, so the two of them weigh ~ 100 lbs and represent the bulk of the system weight (total ~ 150 lbs)
  • The recommended battery is a Lifeline GPL-24 size and the system is designed around their performance.
  • These are also one of the key reasons that it will work over an extended temperature range.
  • The electronics, case, wiring, and mounting were also designed with this extended temperature range in mind.

There are two "boxes" included:

Main Case
  • The main case is ~ 20 x 30 x 12 inches and looks like a heavy duty suitcase
  • It is similar to a Pelican case, but it is a heavier duty and made from ABS to withstand a wider temperature range without cracking.
  • It is a commercially made, domestically produced product. Used pretty widely especially for mil stuff.
  • This can be mounted either flat on the floor or upright as shown.

  • All of the internal components are mounted on a finished, 18mm thick, fine ply type baltic birch / hard maple faced base plate
  • One way to mount it is to use heavy duty straps through the handles that are on it
  • Another way to mount it is to open the box and run bolts or screws through open areas of the baltic birch base plate
The case without the batteries weighs ~ 50 lbs. What I prefer to do is put the case in the van without the batteries inside, and then install the batteries once it is inside of the van. That way it is 3 pieces, ~ 50 lbs each.

The other way I have moved it in / out of the van is using a ramp made from 2x4s.

The second smaller box is the regulated 12 volt distribution box.
- It is an off the shelf, Canadian made, powder coated aluminum electrical box.
~ 6 x 10 x 2 inches
  • This can be mounted anywhere in the van, typically it is mounted close to the bulk of the 12 volt loads
  • Inside is a blue sea fuse block just like the ones used in vans commonly.
  • 24 volt DC is fed into the internal DC - DC converter. This outputs ~ 13.2 volts and this is fed to the blue sea fuse block
  • When the cover is closed, it forms a reliable way to keep out water spills, children, and other accidental contact
  • It is designed for up to 30 amps @ 12 volt continuous use. More loads than this can be attached as most loads do not run at the same time.
  • If more of these are needed, they can be added

The most common way to mount it is to drill a few holes through the back and screw it to a surface.

Premium Member
1,439 Posts
Discussion Starter · #3 · (Edited)
N, I looked at your 1x1 system & have a few questions. What is the charging rate of the 12v "cigarette lighter" socket? What is the output of the included solar panel? If you add 12v branch lines (Frige, furnace, etc) then the 1x1 is not readily portable, is it.? Or are there plugs on the outside of the case beside the USBs & 12v duplex? Do the 2 not included batteries fit inside the case? One photo show a pic of some wiring in a 12" box. Is that box inside the bigger case? What do the colored boxes in some pics represent? How do customers move them and secure them in a van? What are the customer demographic? Thank you.
12 volt DC power in / battery charger:
  • It is designed to pull ~ 8 amps from a 12 volt source and charge the battery pack.
  • It will continue to draw power as long as there is a source and the battery pack needs a charge
  • One way to turn this on / off is to connect to a fused location in the van that turns on / off with the engine
  • Another way is to use a cigarette lighter (now called power port) 12 volt plug, as typically these turn on / off with the engine.
  • The typical port like this is rated for 15 amps, but not continuous use. I set it up for 8 amps to be well within the realistic capability of the these outlets

24 volt DC power outputs:
  • There are three each, fused DC port locations
  • Internally, they are a fused, DC connection to the internal bus bar / battery pack.

Typically I set up the 3 ports as:
- 1 each, dual outlet USB
(this one)

- 2 each, 24 volt / 15 amp fused (can be changed to 30 amp if needed)

One of these feeds the 12 volt distribution box. The second is a spare.

If you need a different port arrangement, but stay within the general capabilities, that is fairly easily done.


The unit shown in the photo was not quite completed when the photographer was available, so not all of the ports that exist are in that particular unit.

The 3 each 24 volt power port locations are on the same side as the 120 vac outlet.

He is a van owner and I traded some electrical work for taking photos.

I need to update those photos.

Premium Member
1,439 Posts
Discussion Starter · #4 · (Edited)
What do the colored boxes in some pics represent? Thank you.
The colored boxes were an attempt to show the "guts" of the 1x1 system in marketing terms for people who are visual learners. It is a general illustration, not an exact representation, but the gist is there.

For example:
  • the two green boxes are batteries
  • black box is the inverter
Those are fairly close to scale in terms of how much room they occupy in the case

The other items are not to scale - I had them all drawn the same size for convenience
  • yellow box is a solar charge controller
  • red box is a 120 vac charger
  • purple box is a battery state of charge monitor / WiFi broadcast so the information can be viewed on any device with any browser.
  • Blue box is the 12 volt input charger
Most of the components are mounted to the baltic birch base plate as shown.

Not shown are the safety related items and wires just to avoid cluttering it up.

My youngest son used a software program called "Blender" to do the 3D lighting / colors, shading. He is slightly embarrassed that the shapes are so simplistic but that is what I asked for. It actually took a fair amount of computing power to simulate colored boxes inside of a clear box with rounded edges and deal with all of the optical effects.

Premium Member
1,439 Posts
Discussion Starter · #5 · (Edited)
120 vac charger
  • There is also a dedicated, built in, 120 vac charger
  • Similar capacity to the solar charger ~ 550 watts
  • It is not part of an integrated inverter / charger, so it provides a way to deal with very poor incoming power quality and surge isolation
  • It will even work as a way to bring in 50 hz power and the system will still output 60 hz.

  • There used to be two different models of these 1 x 1s
  • One was for emergency preparedness / disaster relief
  • One was for Van use

In late 2020 / early 2021, I figured out how to re-design it so that one model does both functions.

Disaster relief / emergency preparedness does not need 12 volt, it just needs USB and 120 vac, so I was now able to make one version and put the 12 volt items in a separate small box.

When I ship to disaster relief areas, typically those units are built with batteries already installed because they don't always have good access to tools at the site. The units for vans ship without batteries. I have access to batteries but I don't really want to be in the battery business.

The most common van users of this model are Promaster owners.

There are also some off road users that are not van owners.

I also have one field scientific instrument user and some other things that I can't discuss.


My own van was totaled in early Sept. Prior to that I was using a larger / 2 kW system to run my off grid shop. Right now I am using my demo unit of this 1x1 model to run it, including lighting, power drill, heat gun, chop saw, microwave, etc. It is a little light for this use so I I have to make sure the saw is fully spun up before engaging the cut.

I also have one at home that runs the garage refrigerator under normal conditions, and we plug the other refrigerator in when the power goes out via an extension cord.

Premium Member
1,439 Posts
Discussion Starter · #6 · (Edited)
It is designed with the intention that everything "plugs in".

Input power
  • Solar - plugs in
  • 12 volt - plugs in
  • 120 vac - plugs in

Output power
  • 120 vac - plugs in
  • 24 volt DC - plugs in
  • USB - plugs in
Edit - sorry - need to add a correction to the output power connection points:

On the "conversion van" model
  • The typical 24 volt output is done by running the wires through a cable gland.
  • The customer crimps a ring lug on and screws it down to the fuse holder.
  • Similar in concept to a blue sea fuse block - but more heavy duty

I used to use a plug at that location but this was easier for most customers.

If you want an plug outlet for the 24 volt so you can connect / disconnect it easily, I can put that on instead


The 12 volt power distribution box is usually mounted in the van, but it "plugs in" to a 24 volt output plug in the main case

Edit - again - this is usually done by running the wire over to the 1x1 - through the cable gland - and crimping on a ring lug. I can make this a plug if you prefer.


Premium Member
1,439 Posts
Discussion Starter · #7 ·

Hi Rob - you asked some questions about power input and power output related details.

I took this photo today - obviously I am very much an amateur compared to the guy that took the other photo, but hopefully it is useful.

The left side of the case is the power input side:
  • 12 volt input connector (shown with a matching connector and loop of wire that comes with it)
  • 2 solar inputs - one connected in the photo
  • 120 vac charger power input with an extension cord plugged in.


Premium Member
1,439 Posts
Discussion Starter · #8 ·
This is the standard power output side:
  • 120 vac / 10 amp / duplex outlet
  • 3 DC output ports

Shown with
  • Position 1 - a blue sea / 4.8 amp dual USB
  • A wire gland pass through if you preferred to hard wire to the internal terminal block
  • Position 3 is unoccupied in the photo, but I can make that location most any connector that you like, for example anderson, a round mil connector, etc.

Typical for vans is usually 1 USB and 2 pass through glands.

I am actually in the middle of building a similar unit for a customer with 2 Battle born batteries / LiFe inside and all of the power input / output on just the "output side".

The customer wants to orient it all with the conventional "power input" face - face down so it will not be accessible.

Take care,


Edit - The small powder coated aluminum box leaning against the 1x1 is the 12 volt distribution. Normally it is mounted near the bulk of the 12 volt loads.

The can of soup and bottle of water are just there for scale.


489 Posts
Thanks for the explanations Harry. It helps understand your product multitudes more than your site. My van is complete and I'm not in your demographic but I've been curious about your product. Pro or not your pics are WAY more informative than the originals. Gotta say, the prices are shocking but if this gives a customer what they want at a price they will pay, good for you. Thanks for all the advice you provide the forum. Your perspective is unique.
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