Hello it's my first time here and I will try to address the issue as best as I can.
I left my keys in the ignition a few days back and hence my battery drained itself.
It is a 12V maintainence-free battery and I want to charge it enough for just one crank. I found a 16v 1.5A adapter and 12V 4A adapter. They are probably old laptop chargers. Could I use anyone of them to charge it?
I have been reading up about it and have seen cases where the wires have melted due to overheating and there are chances of explosion too. Normally a 14V adapter would be ideal but 12V or 16V should work too right? But I am worried about the Amperage since a heavy current will fast charge and damage the battery.
Personally I feel the 12V 4A adapter might not be able to charge the battery that efficiently,since a multimeter reading shows the battery to be at 11V and a 4A current might be too high. So the 16V seems like a better option.
Plus my multimeter's Amperage measurement is damaged so I have no way to take current reading when connecting the battery to the 16V adapter. But could I connect them without a resistance since the current is only 1.4A and constantly check for overheating? I just need enough for one crank and the battery is new, not even a year old with no corrosions on the terminals or leakage.
Sorry if this was too long and thanks for any help/advice.
PS: I really want to charge it on my own and understand there are risks involved. I'm planning to make a proper battery charger on my own in future, but for now I lack the technicalities involved.