Battery acid top up necessary?

[DiscoMick]

This may be a dumb question, so apologies if so...
Do batteries need topping up with battery acid, or is distilled water sufficient? Reason I ask is the battery in the camper has needed topping up twice in the last month. The fridge started to run at unusual temperatures, and investigation revealed low levels in the cells, so I've twice topped them up with distilled water.
This morning, with the camper plugged into the 240 volt multi-stage charger, the fridge was on the normal temperature, but the battery was making a noticeable sound after being topped up and charged overnight.
So, with that much topping up with distilled water, I'm wondering if the battery acid has become too diluted and it needs more acid, or whether the battery has simply carked it and isn't charging properly.
Any ideas?

[drivesafe]

Hi Mick and you never top up the battery’s acid.

If your battery is consuming high amounts of water, then either the battery is on it’s way out or your battery charger is over charging your battery.

With the battery charger connected and running, measure the voltage at the battery’s terminals and see what you get.

[DiscoMick]

OK, thanks for that - eliminates that as a possible cause.
I'll check the charger tonight, but I'll be surprised if it is overcharging. I suspect the battery has simply carked it and isn't holding the charge.
Might go for an AGM next time. Main use is to run the 40 litre Engel, plus a bit of LED lighting.

[DeanoH]

.........................................This morning, with the camper plugged into the 240 volt multi-stage charger, the fridge was on the normal temperature, but the battery was making a noticeable sound after being topped up and charged overnight. ...............................
Any ideas?

Batterys don't have any moving parts to make any noise but when charging oxygen and hydrogen is given off and this makes a faint 'bubbling' sound. This is quite normal. :)

A common problem with flooded cell lead acid batterys (normal car batterys) when used in off road, corrugated road situations is that a cell can 'collapse'. This is when one or more of the plates breaks off inside the battery and short circuits a cell internally, so you have in effect a 10 volt 5 cell battery instead of a 12 volt 6 cell battery. :(

When charging instead of having the charge voltage spread across 6 cells it is now spread across 5 cells (as the 6th cell is a short circuit) which results in the battery 'cooking' because the charge voltage per cell is now too high.This sounds a bit like frying bacon as the good cells are overcharging and possibly boiling. This results in a major loss of water from the cell. When this happens you can often smell the sulphuric acid fumes. :eek:

So if your battery needs topping up in 5 of its 6 cells, is hot to the touch, smells of acid, has dampness around 5 of its 6 filler caps and has an at rest voltage of approx. 10 - 11 volts when fully charged, then you've got a collapsed cell. :(

I replaced the batterys in the OKA several years ago with Optima spiral wound AGM's and haven't had a battery failure since. Prior to this I averaged one battery failure per year with outback corrugated road travel.

Deano :)

ps. Battery electrolyte is a mixture of sulphuric acid and water. Sulphuric Acid boils at 337 degrees C, water boils at 100 degrees C, so when the electrolyte boils/evaporates it's the water that goes not the acid. This is why you always top up a battery with water not acid. :D:D

[sheerluck]

Thanks for that explanation Deano. I normally manage to learn something new on this site every day. That was the one for today!

[DiscoMick]

The battery was still gurgling away when I got home, with a strong fume smell, so I've turned off the charger, plugged the fridge directly into the power, and decided I need a new battery. Thanks for all your useful information people. Now I just need to buy a new battery from my next pay.

[Mick_Marsh]

Following on from the theme, where would I get a battery acid top up?
Saturday, I bought a new lead acid battery. I put it in the boot of the car. Saturday night I swerved violently to avoid Skippy who was sitting in the middle of the road. (It was dark and on a curvey road.) This afternoon I found the battery sitting on it's side it's contents dribbling out. Hence my question.

[JDNSW]

Following on from the theme, where would I get a battery acid top up?
.......

Should be available from a specialist battery supplier - or they would at least be able to point you in the right direction. In the past, batteries were manufactured and supplied to retailers dry and filled wwith acid at the point of sale, so they all had supplies of acid, but today, could be a problem.

John

[THE BOOGER]

Supercheap have battery acid but will normally only sell it with a new battery, they still sell MC batteries dry :)

[Mick_Marsh]

Went down to Supercheap today and explained my story. "Do you sell battery acid?" I asked.
The reply "Government regulations prevent us from selling battery acid."
"Will you top it up for me then?"
"You top them up with distilled water." was the reply.
Oh well, I should have just taken the battery down and said "You sold me a stuffed battery. I want a new one. That may yet happen.

Went into another auto store. Explained my story. "Do you sell battery acid?" I asked.
"We don't deal in hazardous materials." he said.
Pointing to the batteries on the shelves, "Are they not hazardous?" I asked.
"No." he said. "They're batteries."

Called into a third auto store. Explained my story. "Do you sell battery acid?" I asked two different spotty faced youths. "You only top them up with battery water" they said. Then an older gentleman stepped in. "You have to have the right SG of battery acid so you add water."
"But" I said, "As the acid has leaked out, wouldn't replacing the acid with water make it a weaker solution?"
You can't just put acid in batteries." he said. "It has to have the right SG. SG changes with temperature so you have to calculate what SG it should be from temperature tables."
Finally someone who knows his stuff. "But it is a brand new battery that has never been used. The specific gravity indicates the health of the electrolyte. Therefore, for a new battery, I shouldn't be expecting the health of the electrolyte to have deteriorated and the standard battery acid mole per litre for a new battery should be used?"

After a pregnant pause, he replied "We don't sell it here."


Where do I go now?

Back to Supercheap. I'll put distilled water in the thing and say "This battery is not holding it's charge. A new one please under the three year warranty."

Sometimes it's just too difficult to do the right thing.

[THE BOOGER]

Mick I am only a short drive from a you day or so and I have some battery acid from super cheap :D Each time I buy a MC battery they give me a 1lt bottle of acid to fill it but they take less than 500ml to fill and I don't throw stuff out :D

[Mick_Marsh]

OK. Start driving.
I'll put the kettle on.


Many more car parts people to annoy yet. I'll try Bursons next weekend. Autobarn through the week.