Powering Desalinators

[Sue & Larry]

I am considering putting a Pur40E water desalinator unit on board and I hope to 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:
The Pur40E watermaker consumes an average of 4 amps. Therefore, during one hour of operation, the power consumption would be 4 amp hours. Although the brochure for the 40E says it produces 1.5 gallons of water per hour, as your battery discharges, your output will decrease accordingly. Users of this model tell us they see an average of 1.2 gallons per hour. To produce five gallons of water, you will need to run the watermaker for 4.2 hours, and this would consume 16.8 amp hours.

When sizing your batteries and solar panels to sustain this system, keep in mind that you can realistically expect 50 percent of the rated amp hour capacity out of your battery bank. If you continually discharge below 50 percent, you will be doing a disservice to your batteries. If you haven't considered it already, you might want to add a battery monitor, like the Link 10 by Heart, so that you can precisely monitor consumption and charging.

There's nothing like the freedom of having an unlimited source of freshwater on board. We just added a watermaker ourselves which we power off our solar panels and we're thrilled with it. If you can work out the supporting details, we're sure you'll enjoy your 40E as well. Good luck to you.