Battery recovery help

[Goahead]

Hi Everyone

Looking for some webpages/links where i can find DIY on how to remove caps from a Lead-acid maintenance-free battery.

A friend give me an old Bosch Silver 12V 100ah 760A battery. (600-044-076 1A)

Its maintenance-free and my voltimeter says 10,7V...state:DEAD

I would like to put the desulfator circuit into it, and try to recover it, but i would first like to see if water levels are ok.

It seems that the battery has some "circles" below top labels, but it doesnt seem caps.

Will i have to drill them?

Can i had water through the "breathing" tubes?

Never understoud what is a maintenance-free battery since for what i have read, they still have acid and water.

Regards from Portugal

Goahead

 

[dnix71]

Sometimes you can lift the label and pry up the small circular plugs on the top.

[Goahead]

Here are some pics from battery:

http://www.fieldlines.com/images/scimages/8828/bat3.JPG

http://www.fieldlines.com/images/scimages/8828/bat2.JPG

http://www.fieldlines.com/images/scimages/8828/bat3.JPG

No caps...

Should i drill 6 holes there, check water and put new caps? or should i trust manufacture and beleive that theres no water needed?

When i try to charge battery i hear a sound like making french fries in hot oil..it doesnt seem the sound of bubling, its something a bit diferent!

Regards

Goahead

[Airstream]

Appears that you have still label left on battery case that needs to be peeled away.

Six even indentations visible in photos is a tell tale there are ports there.

[Goahead]

Hi Airstream

I tried to scratch but its only plastic...no more labels there.

Its seems it has a cover that includes all six holes, but even with a screw driver i cant remove it...totaly glued into case. I would have to break it all to be able to see results.

Anyone cross to such battery?

What would be my next step?

bubbling like hot oil stops after 1 minute charging...then its only silence.

1 hour charging and battery gets from 10.5 to 12.8 floating, but it starts to get down 0,01 volt every 5 seconds.

Charging 15V 3 Amps

kind regards

Goahead

[zap]

Don't trust that it doesn't need water!  Maintenace-free only means it's been sealed up to keep people from getting inside, water will boil off.

The indentations you see are probably the caps that have been molded into the battery's lid.

If you hear sizzling (frying french fries sound) there's a good chance the grid is partially exposed.

If it was my battery, I'd cut the top portion off as shown but not shown is the cut all around the top of the battery at the same level.

[Goahead]

Hi Zap

Manage to cut some holes..in a simpler way.

I put some water in it, but it seems that water level was not bad after all the years.

http://www.fieldlines.com/images/scimages/8828/bat4.JPG

Charging battery with APC UPS 500...i know it will take forever, since the battery from ups is a 7AH and apc claims it takes about 6 hours to charge...

So for a 100AH it may take more then 72 hours or even not get full charged at all.

Its just for testing.

http://www.fieldlines.com/images/scimages/8828/bat5.JPG

Battery as now reach 13Volt...and its bubling.

http://www.fieldlines.com/images/scimages/8828/bat6.JPG

Hope to get desulfator next year to help on clean it up.

With a 75W lamp connected to ups it takes about a secound to ups disconnects the light and starts beeping.

Ill try again in a couple of hours to see if battery can old lamp on for a bit more this time.

I also have a 3A power supply that i may also connect instead of UPS, to charge the battery a bit faster.

Ill post progress.

Regards

Goahead

[ghurd]

"With a 75W lamp connected to ups it takes about a secound to ups disconnects the light and starts beeping"

And

"1 hour charging and battery gets from 10.5 to 12.8 floating, but it starts to get down 0,01 volt every 5 seconds"

I call that a Dead Cell.  A very seriously Dead Cell.

Not worth the effort of even trying a desulfator on something that bad.

It is toast.

G-

[Goahead]

i hope your wrong

i made some reading in each cell with multimeter, and i do have 2 volts from cell to cell and cell to positive and negative poll...

Do you know if i still would have a dead cell even readind 2volts?

Does a dead cell means 0Volts or something like 1,5volts?

regards

Goahead