without an Alfa
Join Date: Dec 2011
Location: United Kingdom
go out and buy a new battery.
the trouble with lead acid batteries is that once they have been discharged beyond a certain point the sulphur (from the acid) drops out and coats the lead plates in the battery. Once this has happened there is no going back and all you have is a very heavy container full of water. Topping up with more water will not help. It is just a fact of life that batteries have a finite lifespan and I often hear people say "but I only bought this battery xxx long ago" it really doesn't matter. If it has been discharged beyond a critical point then it has had it.
If you want to confirm this then get hold of a hydrometer to measure the specific gravity of the electrolyte in each of the cells (the more acidic the electrolyte the denser it is)
another useful test is to see how much the voltage drops under load. It should normally read around 12.6 volts when not loaded. If you then get someone to turn the key and try to start it whilst reading the voltage (taking care not to get tangled up in any moving parts) and see where the voltage drops to.
If it goes below around 10 volts then it is probably no good
Last edited by jonny rash; 23-09-12 at 21:27.