Watermaker water to refill batteries

[ObiWanSand]

Hi all!

I was wandering if there is any merit to the idea of using watermaker water, to refill batteries? After all the water is quite sterile having gone through 5 micron filters?

Has anyone tried and are willing to share experiences ?

PS!
Sorry if this has already been discussed, would be happy if someone could post the relevant links.

[a64pilot]

Better than letting them go dry, but not by much.
Use distilled water, or if you can't get it, use airconditioner condensate as its distilled. ( I will get argument with that, watch )
I believe a watermaker as far as RO units go is not a real good unit, it produces drinkable water, but not "pure" water. Actually water like from a Dialysis RO unit will eat up plumbing, its so pure and water being the universal solvent, it will dissolve the metal in pipes and fixtures etc.
You don't want to drink "pure" water by the way, it tastes like crap and will leech minerals from your body. ( bet I get argument on that too )

[Lepke]

It depends on the water source. Water made from salt water has a lot of dissolved solids compared to water made from fresh. I make my water all the time, both in fresh and salt. I also use several filters, the finest being 1 micron.
I use a TDS meter and salt usually reads above 200 ppm and fresh 0. When making from fresh, I bottle some for the batteries and have had no problems with battery life.
I've had Dyno batteries go many years past their expected life.

[roverhi]

The problem is dissolved minerals in the water. Water makers don't remove all these minerals while distilling does. If you've got nothing else, better to use water maker water than water from the tap. Putting less than distilled water in your batteries won't cause immediate failure of the batteries and may not even shorten their life enough to notice but why take a chance. A gallon of distilled water lasts me more than a year so minimal expense for the peace of mind.

[jcapo]

For really low TDS watermaker water, run the product water through the watermaker again. I think it was the Cruisero dude that suggested that but I could be wrong.

[SV THIRD DAY]

Originally Posted by ObiWanSand

Hi all!

I was wandering if there is any merit to the idea of using watermaker water, to refill batteries? After all the water is quite sterile having gone through 5 micron filters?

Has anyone tried and are willing to share experiences ?

PS!
Sorry if this has already been discussed, would be happy if someone could post the relevant links.

It's a very bad idea.
Sea Water RO has a TDS of 120-500ppm and that's enough solids to over time kill your batteries.

Now some folks will run fresh water through their Sea Water RO to get the TDS down to low single digits...but that's still a risk.

For batteries I would use zero TDS distilled water and not take any risks. It's hard enough to keep your batteries healthy, so I wouldn't recommend it.

[boatbod]

Ok here goes...

Air conditioner "condensate" water is so disgustingly nasty I wouldn't feed it to my enemies, never mind putting it in my batteries.

Why? Perhaps because it condenses all over the evaporator coils which are open to air flow from the boat, which includes dirt, dust and bacteria. Once the water had dripped down from the coil it then collects in a pan, which on most boats is rusty as all hell and again quite possibly contaminated with mold and all manner of debris.

Your air conditioner might be spotless and capable of making sterile water. None of the ones I've seen or worked on come anywhere close.

[svlamorocha]

Originally Posted by ObiWanSand

Hi all!

I was wandering if there is any merit to the idea of using watermaker water, to refill batteries? After all the water is quite sterile having gone through 5 micron filters?

Has anyone tried and are willing to share experiences ?

PS!
Sorry if this has already been discussed, would be happy if someone could post the relevant links.

The 5-micron filters are on the feed side of the watermaker and do not filter DISSOLVED material (ions) that is left in the product water.

[travellerw]

I know tons of cruisers that put RO water in thier batteries.. They may not do it every time, but certainly they do it. I have done it when I can't get distilled water.

[a64pilot]

Originally Posted by boatbod

Your air conditioner might be spotless and capable of making sterile water. None of the ones I've seen or worked on come anywhere close.

It's not sterility as in no biological life we are after, but lack of dissolved solids, I believe the TDS meter may stand for total dissolved solids?
Anyway, yes mine as it's only a couple of years old is nearly spotless, but its powder coated stainless steel. The one I took out looked like you said, a rusty mess. I guess maybe because I am a little concerned about what can be growing in that pan, and what is, I'm breathing that I keep it clean. Mine is accessible and it's not hard. I have a regular air filter before the AC and it has its own filter as well so it keeps the evaporator clean, a clean evaporator makes the AC work so much better and blow more air and colder air too.
Funny thing is it's a cheapo AC , a Webasto

[Kenomac]

Simple answer: Don't do it! Distilled water only for your batteries. RO water is not the same as distilled.

[Emouchet]

If you do not have any distilled water available and need to urgently add water to the battery, you could scrap the frost from the fridge cold plate and let it melt. That ice does not contain much mineral.

Filter it through a coffee filter may also help to get rid of large artefact.

[wrwakefield]

Originally Posted by ObiWanSand

Hi all!

I was wandering if there is any merit to the idea of using watermaker water, to refill batteries? After all the water is quite sterile having gone through 5 micron filters?

Has anyone tried and are willing to share experiences ?

PS!
Sorry if this has already been discussed, would be happy if someone could post the relevant links.

From Trojan batteries: Effects of Impurities on Lead-Acid Batteries.

Max allowable dissolved solids 100ppm in battery water...

Cheers!

Bill

[S/V Alchemy]

An inability to source distilled water and to keep a jug of it aboard (which should, after all, last some time) speaks of bad planning to me.

That said, you could make a fair bit from a solar still, I would think, or the old-fashioned way of condensing steam from a kettle using appropriate tubing.

[accomplice]

According to a Trojan white paper, total dissolved solids for electrolyte in a lead acid battery should be < 100ppm, with some minerals much lower. Our watermaker water is usually 150-200ppm Na, but I have used it in flooded lead acid batteries without observable adverse effect. Although the sodium content of RO water may be close to the manufacturer recommendations, I do not know how well the watermaker filters out other minerals which can be damaging to batteries even in much lower concentration.