Rainman 12 Volt DC Watermaker

The 12VDC system is the Rainman watermaker that consumes the least power.

It’s a very simple and highly reliable system that can make up to 34 liters (9 gallons) of fresh potable water per hour.

Options exist for this system to be run completely portable without any plumbing or fully plumbed in with a minimum footprint installation.

Our 12VDC system is a great option if you don’t have AC power available but want to avoid the complexities and maintenance requirements of more efficient energy recovery systems.

Unlike the AC (electric) or petrol (gasoline) powered Rainman Watermaker, the 12VDC is compatible only with the single 40″ RO membrane.

Power options

With recent advancements batteries, solar, and wind power, it is easier than ever to have sufficient useable amp-hours available for running your appliances.

Our 12VDC system requires 410 watts, or about 30 amps, to operate.

Installed or portable watermaker

Our traditional system in the blue case can be used as either portable or installed. If you wish to install it, it becomes a two box installation.

It is worth noting that due to the lower output and shorter power cord of our 12VDC, most customers with this system will choose to fully install the watermaker.

12v dc electric watermaker for catamaran

Reverse Osmosis (RO) unit

12VDC Economy RO Unit

Due to the lower flow rate of the 12VDC PSU, only the single 40″ membrane configuration of the Economy RO unit is supported. This can either be in the traditional blue case or Naked in the easy mounting bracket.

This system will make 26-34 liters per hour (7-9 gph).

Cased or naked options

The system can be purchased either as the traditional blue case version or in the Naked configuration. The pricing, performance and power consumption are identical between the two options, so your specific requirements control which is best suited for your application.

The table below summarizes the differences between the two options.


  • Permanent magnet TEFC DC Motor
  • 410 watts steady state power consumption
  • Current draw 30 amps
  • Power cord length: 1.4 meters (4.5 ft) including battery connectors
  • Plug type choices: Anderson Style
  • Integrated flexible impeller lift pump uses non-proprietary impeller
  • 2 meter (6 ft) maximum lift above sea level
  • General Pump WMR 316 stainless steel high pressure triplex plunger pump
  • Integrated General Pump 316SS/ceramic relief valve to prevent overpressurisation
  • Sound levels: 58dB at 6 meters (20 ft)


cased 12v dc watermaker


  • Case of sturdy injection molded polypropylene
  • PSU storage/mounting seat: fiberglass reinforced nylon with strap
  • RO Case (mountable if desired): rotomolded polyethylene
  • Plumbing installation kit at extra cost
  • Single 10″ x 2.5″ non-proprietary 5 micron pre filter to remove sediment mounted on PSU
  • 0 – 40 lph (11 gph) product water flow meter, integrated in to RO case
  • Valve / gauge control assembly integrated into RO case
  • 5 meter (16 ft) intake hose fitted with one way valve to remain primed, with detachable strainer
  • 3 meter (10 ft) brine waste discharge hose
  • PSU weight: 24kg (53lb)
  • PSU Dimensions: 600 x 375 x 270mm (23.6 x 14.8 x 10.6″)

Related RO weight:
– Economy: 11kg (24lb)

Related RO dimensions:
– Economy: 1,180 x 250 x 130mm (46.5 x 9.8 x 5.1″)

naked 12v dc desalination system


  • No shell
  • PSU easy mounting kit: fiberglass reinforced nylon for high rigidity and tensile strength
  • RO easy mounting kit: fiberglass reinforced nylon for high rigidity and tensile strength
  • Plumbing installation kit included with purchase
  • Single 10″ x 2.5″ non-proprietary 5 micron pre filter to remove sediment with SS316 mounting bracket
  • 0 – 40 lph (11 gph) product water flow meter, with SS316 mounting bracket
  • Valve / gauge control assembly at end of 5 meter (16 ft) high pressure hose for remote mounting
  • 5 meter (16 ft) intake hose
  • 6 meter (20 ft) brine waste discharge hose
  • PSU weight: 23kg (51lb)
  • PSU Dimensions: 470 x 270 x 240mm (18.5 x 10.7 x 9.5″)

Related RO weight:
– Economy: 10kg (22lb)

Related RO dimensions (in mounting brackets):
– Economy: 1,170 x 220 x 120mm (46.0 x 8.7 x 4.7″)

Optional accessories for your Rainman Watermaker

Control Panel

The control panel retains the simplicity that Rainman is known for, while adding a number of features to allow for simpler access and remote control.

Autoflush System

The Rainman watermaker is a very robust piece of equipment, but caring for certain aspects will prolong the usable life – try the Autoflush System!


As your membranes age, the TDS (total dissolved solids) of the product water increases. A hydrotester will measure the water quality.

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