ML battery, is it leaking?

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dokalj

MB Enthusiast
Joined
Feb 23, 2009
Messages
1,562
Hi all,

I hope everyone is well.

I have a question about the ML.

Does this look like a leaking battery? I think it is, however would like to be told it isn't.

Please see attached.

Kind Regards

dokalj
 
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Lift it out and have a look below. It looks like it's either been overfilled or is boiling due to over-charging.
 
Last Picture.

Thanks

dokalj
 
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Lift it out and have a look below. It looks like it's either been overfilled or is boiling due to over-charging.

Thanks for the quick reply. :)

Over filled? Boiling due to over-charging?

Are these batteries not sealed?

Also with regards to over-charging why would that happen? Or do you mean using a charger and not the car?

Thanks

dokalj
 
It's not a sealed battery, hence the caps to unscrew. Unscrew the caps and check the level, then check the charging voltage, it' should be 13.5-14.5v, no more, no less.
 
It's not a sealed battery, hence the caps to unscrew. Unscrew the caps and check the level, then check the charging voltage, it' should be 13.5-14.5v, no more, no less.

If the voltage is around that and the distilled water does not look overfilled, what could it indicate?
 
Then it looks like it's leaking, but from the top..??

I am not sure where it is leaking from, if it is.

I am suprised it has happened if not, something has happened.

To be honest it has got worse.
 
All car batteries should have vent holes, usually either end and as described in previous links.

You need to remove the 6 cross head filler covers on the top of the battery and top up, so as to just cover each cell with DISTILLED water, obtain from your local Chemists or Halfords, you will then need to clean up the battery and the spilled battery acid on the paint work using plenty of boiling water.

Dec
 
How old is the battery. I suspect it has a dead cell so is boiling that cell when charging.
 
All batteries bubble when charging, but it shouldn't be excessive.
 
.....Update.....

When the car is off the battery reads: 12.62V
When the car is running the battery reads: 14.86V

What would this deduce?

Thanks

dokalj
 
In the charged state, each cell contains electrodes of lead and lead oxide in an electrolyte of approximately 33.5% v/v sulphuric acid.
In the discharged state both electrodes turn into lead sulphate and the electrolyte loses it’s dissolved sulphuric acid and becomes primarily water. This is why batteries that are discharged are more at risk of freezing in winter battery
When you charge a battery you are changing the lead sulphates into lead and lead oxides. The process is driven by the forcing the removal of electrons from the anode and the transfer of them to the cathode,
Charging generates oxygen and hydrogen gas by electrolysis of water, which is lost to the cell, hence the bubbling when charging and the need for venting.

 
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Does this mean my battery is fine?

I did open up the screws and the second screw closer to the driver was wet around the screw. I still have liquid around the base of the battery and the reservoirs were not filled to the top.
 
The charge voltage looks a bit high, which could cause boiling.
 
The charge voltage looks a bit high, which could cause boiling.

Are you hinting at the alternator Dieselman?
 

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