The brother-in-law has an old car that he wanted to take to the breakers yard and asked if I could charge the battery. It had been stood for several months without starting so was flatter than a witches tit. I measured the voltage at the terminals and it read 1.6volts. I said it may be too far knackered but would give it a try. I have 2 battery chargers, one is a new 3 phase charger from Lidl and the other a donkeys years old basic 6amp charger with switchable 6 or 12 volts.
I tried to charge using the new 3 phase charger but it would not even come out of standby mode. I then tried the old 6amp charger and when I switched it on the needle on the amp meter started to rise & rise and went completely off the scale. It was only connected for a few moments and when I measured the battery voltage it now read over 13v so I disconnected the old charger and reconnected the new 3 phase charger and it now went into charge mode and was fully charged about 15 hours later.
I think this has damaged the old charger as when I now try and connect the charger leads to a battery it causes a short with loads of sparks (this is before the charger is switched on). If I switch on the charger without the leads connected the charger makes a clicking sound as though it's continually cutting on & off. I'm guessing that trying to charge a battery so flat has forced more current from the charger than it was designed to give? Before I take a look inside (or bin the thing) I just wondered if anyone had an idea what might have gone kaput.