TDS of distilled / demineralised water?

[Tim Good]

I top up my Trojan batteries with demineralised water which I was told is the same as distilled. I bought it in France from an Auto store for batteries.

Anyway I was just topping up my batteries and had my TDS meter out son the desk o I thought I'd give the demineralised water a test. Came up with 1100!!!!!

Shouldn't it be near zero? Has anyone else found that TDS meters can be inaccurate with distilled water? It seems to be accurate for tap water and water made from our water maker.

Also if distilled water was sat in its plastic container for a year could plastic leach into it to make it read high on a TDS scale?

 

[pvb]

Sounds like dodgy water. Demineralised should be under 10ppm TDS. It may not make a lot of difference though to your batteries.

 

[Tim Good]

Sounds like dodgy water. Demineralised should be under 10ppm TDS. It may not make a lot of difference though to your batteries.

Thanks PVB... I just edited my posted as I realised the TDS actually read 110 (x10). It was off the scale so a little flashing (x10 appears). Had to look it up in the manual which means 1100ppm!!!

 

[macd]

Trojan recommends a max TDS of 100ppm. (Although the max for certain specific impurities is very much less.)

 

[pvb]

Thanks PVB... I just edited my posted as I realised the TDS actually read 110 (x10). It was off the scale so a little flashing (x10 appears). Had to look it up in the manual which means 1100ppm!!!

That's very high. Is your meter working OK? Perhaps check it against natural mineral water, which should show maybe 200ppm.

 

[vas]

That's very high. Is your meter working OK? Perhaps check it against natural mineral water, which should show maybe 200ppm.

+1

tap water down here (and it's BAD!) is at 500-700
RO installed at home water down to under 60iirc

 

[Tim Good]

That's very high. Is your meter working OK? Perhaps check it against natural mineral water, which should show maybe 200ppm.

I think my TDS meter is ok. It reads about 350 from our water maker and 200ish from bottle water approx.