I am considering buying a Pur40E water desalinator. I hope run it off of a battery, charged by a solar panel. How many amps does the unit draw to operate per hour?
Sue & Larry respond:
Having just added a watermaker ourselves to Serengeti about a year and a half ago, we can certainly vouch for the wonderful freedom of having an unlimited amount of freshwater onboard. Solar panels can certainly power these units, as that’s our main source of power.
Cruisers that we know using the PUR40E tell us that it consumes approximately four amps per hour of operation. The output of this model is reported in the brochure to be one-and-a-half gallons per hour, but as your battery discharges output also decreases. For planning purposes our friends tell us that they see an average of one and two tenths gallons per hour.
When sizing your solar panels and battery bank, keep in mind that you can realistically expect to use only 50% of the rated amp hour capacity of your battery bank. The addition of a battery monitor can help you more precisely monitor consumption and charging. If you continually discharge below the 50-percent level, you will considerably lessen the life of your batteries. You may want to check out our article, Choosing and Installing Solar Panels, archived here at SailNet.
