Battery top-up - to what level?

[Homer2911]

Stupid question - how do I know to what level I should top up a battery, and whatever happened to those special top-up bottles that set

the level automatically?

[Dave Plowman (News)]

You just add distilled water so the electrolyte just covers the plates. If you can't see them use a torch. Not match. Oh no.

[mrcheerful]

ordinary batteries are topped up to just a bit above the metal bits you can see, say about a quarter of an inch or 6mm

mrcheerful

[Ian Stirling]

And to quote a Haynes manual. Torch in this manual refers to a battery operated electric lantern, and not what you see villagers carrying in vampire films.

[David Lang]

Hi Homer

Just above the level of the plates as others have said............. BUT!

ONLY when the battery is fully charged!

As a battery discharges the electrolyte level drops. If you top up a flat battery, when it's charged, the electrolyte level rises again.

This can cause electrolyte to overflow and leave the battery. Topping it up again dilutes the electrolyte, ending up with a knackered battery. And so on, and so on.

Dave - who used to earn a great deal of dosh from people who didn't understand traction batteries.

[:::Jerry::::]

So you would suggest charging a flat battery with the electrolyte

*below* the level of the plates?....

Topping it up

Only if you *grossly* over fill the battery....

Jerry - who used to make the bloody things, fill them (when totally flat) and then charge them from new. You don't know the first thing matey, most of what you said above is total bullshit or at best the words of someone who knows less than they think they do...

[:::Jerry::::]

Automatically ?!....

If you mean the Lucas ones, they had a red (captive) strip type lid, the automatic levelling never really worked correctly and were a bastard to fill to the correct level in a normal way due to the design of the top and lid assembly.

[:::Jerry::::]

design

Fiddle-sticks ! Sorry, missed the word 'bottles', thought you were talking about the above battery type.

[Dave Plowman (News)]

Years ago there were distilled water bottles at every filling station, and they had a valve in the spout which sort of stuck out. You inverted the bottle and no water came out until you pressed this valve on the plates, then the water cut off automatically at the correct level above the plates.

[Dave Plowman (News)]

So you're implying a fully charged battery with the electrolyte at the correct level will drop below the top of the plates when discharged?

Not in my experience.

If you grossly overfill it of course. Hence the just above the plates bit.

[David Lang]

Hi Jerry

Nope. The plates should be just covered. Forgot that bit.

Which happens all the time. I'm refering to 18 x 2v cell deep cycle traction batteries used in floor cleaning machines, in retail supermarket applications.

The people cleaning the floors are in the main muppets on minimum wage, most couldn't tie their own shoe laces, let alone follow simple instructions.

We had the batteries in a 2" deep stainless steel tray - which we often found full of electrolyte.

Care to explain your point instead of just being rude............

Dave

[:::Jerry::::]

'nough said....

When you can't even get the basics correct, what credence should be given to anything else you say ? :~(

[David Lang]

Hi Dave

Nope! There is an expansion gap. In a fully charged battery the electrolyte will drop to a lower level, but still cover the plates.

If you correctly top up a discharged battery, when it charges the level will rise and fill the expansion gap. If you over top a discharged battery e.g. fill it right up, it will overflow as it charges.

Gross over topping is common in some areas of use. like supermarket cleaning.

Dave

[Dave Plowman (News)]

Then I doubt it would matter whether the battery was charged or discharged. Fools can wreck anything. ;-)

[:::Jerry::::]

Something you seem to know a lot about....

[David Lang]

Jerry wrote;

As a matter of fact I do. Your rather snide implication was that I actually cleaned them myself, and that doing so was a menial job - which I suppose it is.

Actually, I sell the capital equipment that cleans them. You are looking at £30K's worth of kit to clean a large superstore.

Instead of sniping and making snide comments, why don't you try making a positive contribution?

If you disagreed with my post on batteries, you could have done so in a way that we all could learn from. Your obviously huge knowledge of them could have been shared by the group to the benefit of all.

Dave

[bigcat]

Batteries normally have some indicator of what level to fill to. Do not fill them to this level if theyre old. Why? Batteries gradually lose H2SO4 during use, and topping up batteries to the fill line has wrecked many an older lead acid battery, by diluting the electrolyte too far. If the thing is not new, it is better to fill it to just cover the plates, say by 2mm.

NT

[Homer2911]

Thanks guys - still searching for that elusive top-up bottle with the automatic levelling feature though - every garage used to sell them whn I was younger!