Katadyne water for Wet Batteries?

[Jim Cate]

So, we are all raised "knowing" that one must use Distilled Water in lead acid batteries or god will strike you dead. Is there a competent chemist out there who can tell me exactly why this is true? What impurities are the bad ones, what level is damaging and so on?

We have used rain water, collected off of a not scrupulously clean awning, for many years, and our T-105s, much abused by deep discharge, have lasted 4 to 6 years. Being that this is similar lifetime to folks who are more conscientious in their battery care than we are, I'm led to question some of the folk wisdom we live with.

Any REAL knowledge out there?

Cheers,

Jim

[sailorboy1]

Originally Posted by Jim Cate

So, we are all raised "knowing" that one must use Distilled Water in lead acid batteries or god will strike you dead. Is there a competent chemist out there who can tell me exactly why this is true?

It's true, but unless you have to add water a lot it isn't really going to make much difference. There are deposit type ions and ions that would effect the pH by increasing it. Most "city" water in the US is pretty good water and varies mostly in things like calcium carbonate and silica. But it isn't worth any battle to argue.

[svinshallah]

Somewhere on the Trojan Battery web site, they have a list of the allowable parts-per-million of contaminants allowable. RO water doesn't come close to meeting the specs. Running RO through the water maker more than once doesn't reduce the level of contaminants. Rainwater is OK as long as you let the first several minutes run off. Distilled water is available in any good-sized pharmacy since it's used by every doctor, dentist and medical lab.

[s/v Jedi]

Originally Posted by svinshallah

Running RO through the water maker more than once doesn't reduce the level of contaminants.

wrong. bet you never did this and tested the results…

[NorthPacific]

Like the idea of Turkey basters. never thought of that. Dollar store in the morning :-)
I think the small bottles is a good idea. See just when I think I know it all lol.

Steve

[hellosailor]

Jim, unless you want to invest in a testing protocol and instruments and whatnot, isn't it easier to just accept that many supplies contain minerals, many of which will interfere with the electrochemical reactions in batteries?

And instead of setting up a lab on your boat, just spend the two bucks a year, or five bucks a year, to use distilled water instead of spending gobs more time testing your water?

To the OP, I'd suggest that every boat has room for at least five one-gallon containers of distilled water. If you're going offshore you need an emergency water supply, separate bottles that are not plumbed into your system, that cannot be contaminated or drained by any problem in your system. We had a "minor inconvenience" once when a hundred gallon tank blew into the bilge, courtesy of a defective safety valve on a hot water tank. The only convenient fuel and water dock was closed in the offseason...but fortunately the nice folks left their water hose on, on the honor system.
So you stash away five jugs of distilled water, share them with the batteries as needed, replace as needed, and you've killed two birds with one stone.

[NorthPacific]

Hello HS,

I have 2 separate 40 gallon water tanks which will not drain each other. 2x2.5 gallon separate tanks for the water maker. 5 day supply of package water for raft. 2x5 gallon emergency tanks if water maker breaks both tanks rupture and beer runs out!

I will find room for distilled water but it just another "thing" that I have to carry. Would have been nice if the Kat could have simplified life. Glad I asked though :-)

From my location I have a 3900 mile run to F poly, so weight on a 35ft is a concern. My boot stripe is getting narrower as we speak. I am on a crash diet trying to save weight :-)
Tahnks for the input

Steve

[Dsanduril]

Originally Posted by Jim Cate

So, we are all raised "knowing" that one must use Distilled Water in lead acid batteries or god will strike you dead. Is there a competent chemist out there who can tell me exactly why this is true? What impurities are the bad ones, what level is damaging and so on?

...

Any REAL knowledge out there?

Cheers,

Jim

This is what Trojan has to say:



Note that at 5 ppm of chloride you start to see a reduction in capacity of both plates. And the bulk of the TDS found in your RO water is Na+ and Cl-,...

You can see the full paper here:

http://www.trojanbattery.com/pdf/WP_...ities_0612.pdf

[NorthPacific]

Thought Trojan made condoms :-)

[Jim Cate]

Originally Posted by Dsanduril

This is what Trojan has to say:

Attachment 73779

Note that at 5 ppm of chloride you start to see a reduction in capacity of both plates. And the bulk of the TDS found in your RO water is Na+ and Cl-,...

You can see the full paper here:

http://www.trojanbattery.com/pdf/WP_...ities_0612.pdf

Well, well: just what I was looking for! That is pretty definitive, and well worth absorbing. I can only wonder what the analysis of our collected rainwater is... the stuff that has seemed to work well over the years.

Oh, BTW: we do buy DI water when it is available and convenient. It isn't so inexpensive here in Oz... tends to run about six bucks for a four litre jug, and that only at a Home Depot clone (Bunnings or Mitre ten), but we lash out and buy it now and then!

Cheers, and thanks to all who tried to help.

Jim

[Jacko]

I have been using rain water in my T105s and they are now 6 years old with live aboard I think lots of battery problems are not simple things like using mains water or what ever, the problems come from over use of the batteries if you are constantly draining them down below 65% or even 75% the life of the battery will be very short so the quality of the replacement water is not the issue. I asked the same question here on CF a few months back and had great advise not to use W/M water We now have the wet season in Far North Qld so have replenished my rain water supplies. Great to see Jim and Anne back in OZ Looking forward to seeing you again Hope the medical issues are all sorted I will be down in the Whitsundays this year for the Regatta if you are coming that far North
Cheers Jacko

[hellosailor]

Steve-
Well, of course, there's the other obvious solution considering you have so many separate tanks already. Build or buy a small water distiller, feed it from rain or your RO water, and just distill a quart or two at a time, when you need battery water. Buy a dissolved solids meter, test the output, redistill if necessary...there are small solar stills sold for use with life rafts, so that can have a dual purpose. Or a sheet of polythene and a bowl will work, although I've no idea just how "zero zero" that gets.
Got a local college with a chem lab? Maybe you can get someone interested in an extra credit project for the most economical purest still, or at least, willing to give you some pointers and testing.

[sailorboy1]

Lot of trouble when all you need is a small bottle of resin with a filter in the cap that will make 99% pure water from tap water and cost around $10 and last for years and years.

I have one in my lab kit for doing chemical testing that holds a quart of water and I use everyday and it lasts years.

[Stu Jackson]

Originally Posted by NorthPacific

Cheers Stu,
Nifty bit of kit. COuld be very useful. Any Snow in your neck of the woods at the moment?

Just envy!:-)

Steve,

Nope, no snow, no rain. My skiing career ended in Jan. 2009 when I broke my leg, but I still like the snow. Lookin' like a big drought year here.

Also, don't forget those 39 pairs of shoes!!! Each!

PS - don't forget the DUAL use for coolant top up.

[hellosailor]

"bottle of resin with a filter in the cap that will make 99% pure water from tap water"
As I recall that makes "de-ionized" water, great for ironing and better than tap for cooling systems, but 99% pure is grossly different from distilled with 5ppm of solids.

5ppm (and your standard may vary) is 5:1,000,000 which is less than 99.999%.