I’m charging some lead acid marine batteries and the instructions say to top off the water levels with distilled water after charging. Fair enough, but I don’t have any distilled water sitting around the place. What I do have, in bucket loads, is water from the cellar dehumidifier. Question: how close to distilled is dehumidifier water?
My thoughts: When distilling, you’re probably dealing with water vapor in the form of steam. When dehumidifying, you’re dealing with water vapor, but also, I would guess, tiny water droplets suspended in air? Which might be capable of transporting trace amounts of minerals? So I’m guessing that condensed water from a dehumidifier would be purer than tap, but maybe harder (from a mineral point of view) than distilled?
If I decide not to use dehumidifier water, how about filtered water from the fridge? It goes through some kind of ion-exchange resin, so I’m guessing that it’s fairly pure. But if they took out all the minerals, it would probably taste crummy. So…fridge filter harder than dehumidifier water which is harder than distilled?