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MG Midget and Sprite Technical - Neutralising battery acid

My Sprite came with quite a lot of white powder (lead sulphate?) on the bulkhead area around the battery and even finding its way down into the passenger footwell. I have had the battery out several times and sluiced the whole area out thoroughly with boiling water but each time, after a couple of weeks the white stuff has returned. The battery terminals are clear of the stuff.

I'm sure the root cause is the acid that's splashing out of the ventilation holes in the top of the Numax battery. The cells are not over-filled, if anything they're a bit low - perhaps that's allowed more sloshing around room! The obvious solution seems to be fitting a gel battery when this one expires - I'm loathe to throw out an otherwise healthy battery.

In the mean time - does anyone have any suggestions for containing the splash without restricting the ventilation? Driving slowly is not an option!

Can anyone recommend any processes or products that will thoroughly clean and neutralise the existing contamination and prevent further fungal growth?

Colin
Colin Mee

Thinking back to my chemistry lessons, you need an alkaline to neutralize acid. I would try Bi-carbonate of soda, it cant do any harm to give it a try.
Pete Ottewell

Colin. Baking soda (sodium bicarbonate) will neutralize the acid splash. For my own use, I find a Optima (gel type) battery works well, does not have to be topped up with water from time to time, and does not have any residue to damage the car. Neutralize the areas that the acid has splashed on, clean them with a wire brush, then paint the areas to prevent rusting.

Les
Les Bengtson

The white salt deposit is probably ferrous sulphate which also exists in a bluish green form as well as white.

Wash it clean with water, dry thoroughly, treat the area with phosphoric acid (naval jelly) and then paint with something like Plastikote.
Chris at Octarine Services

Colin,
it may not be splashing, so much as fumes. Many batteries now have a small vent that can be connected to a length of plastic washer tubing and lead away into clear air. Several modern cars I have come across that have the battery in a contained area of the boot use this system.
Guy W

Thanks for the quick responses - very helpful.

Guy, I think Numax is probably from the budget end - individual cells with just a small vent hole leaving droplets on the top of the battery. No sensible drain tubes - but that has got me thinking. Perhaps some sort of plastic cover with a breather tube venting below the car.
Colin Mee

hi colin,
i had that regular on one of my cars.boiling water should do the job. but every time i cleaned it off it reappeared a few days later. this kept happening untill i noticed that where the top part of the battery case was sealed to the bottom half it was leaking around the join. new battery and all ok.
bob.
bob taylor

Colin, the last battery I bought not long ago had these vent tubes. And it was certainly a budget one - literally half the price of the Halfords equivalent. I bought it online from Carparts4less. When it came it was packaged and wrapped with a yellow absorbent padding material printed with the word "Acidabsorber". I assume this is a trade name but if that is its purpose a piece of something similar taped across the top of your spitting filler plugs might at least contain your problem. The battery compartment area needs washing down with hot water/ bicarb solution to stop the white powder (and corrosion) coming back.
Guy W

All great advice given so far:

1) baking soda + warm water to neutralize the acid already on the body work and to wash it away.

2) in the future use an acid matt to prevent future spills from causing as much damage (here is a link to it):
http://www.amazon.com/The-Battery-Mat-Acid-Neutralizing/dp/B002PCU1U0/ref=sr_1_1?s=automotive&ie=UTF8&qid=1372849257&sr=1-1

3) a battery that keeps losing fluid out the top might be overcharged by your system (boiling it out the top) - it may be a good idea to have your alternator output checked, just in case


Battery acid and the associated caustic fumes will cause rust, and it is difficult to be sure that you have successfully rinsed it all way. Any acid that you have missed will cause rust for years later. Once that rust has gotten started it is then too late for you to prevent it.

Optima AGM batteries are great, but too large for our little battery tray (if you keep the heater and the stock battery location), but the Westco battery (special, small AGM battery for Mazda Miata) uses the same technology in a smaller package and fits great.

http://estorebc.mkbattery.com/Category/41_1/Miata.aspx

If your car is already pretty rusty, then, by all means, save $50 and wait until your leaking battery finally dies and causes as much corrosion in your car as possible. What is that battery worth? $50?
But, my advice is to replace it ASAP, before it causes any more damage.
A sealed battery like the Westco costs $150, but if you have nice bodywork, that is a small price to pay to preserve it.


Norm

Norm Kerr

This thread was discussed between 02/07/2013 and 03/07/2013

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