YES always disconnect the negative cable from the battery first then just be careful to hook up the negative cable to the battery as the last step
clean the battery terminals - strong wire brush or a little baking soda & water.
A car battery is a wet cell. Only recently have dry cells been introduced, but your typical car battery is a wet lead storage battery.
Yes. If you touch both terminals (-and+) with anything that will conduct electricity the battery will discharge. Try putting a 9 volt to your tounge. All batteries will cause a mild shock. There is also a risk of the battery leaking some very harmful materials as they are not ment to be wet!
wet cell battery
If the water penetrates the phone's casing, it may cause a short circuit, when the water covers two or more electric terminals. If a short circuit does not occur, then the phone should still work, once completely dried. If you get your phone wet, remove the battery, and put it in a dry and warm place.
Nothing it will not harm the battery at all. It is sealed from outside elements. I do not mean putting it under the water as that would short it out. But to rinse it off is fine.
I assume we're talking about the typical wet-cell battery. Usually it is filled with a mixture of acid and water. If the water is gone the battery is damaged and cannot be fixed by refilling it with acid and water.
what happens if you tuen on the phone and it is wet
Rechargeable battery or electrochemical battery.
I am assuming you are talking about cleaning the top of a lead-acid battery. I am also assuming that the "clamps" are the battery terminals that clamp onto the battery posts with a pinch bolt. If this is the case then... Yup, In fact we do it all the time. There is bound to be a bit of "stray" voltage between the battery posts when the battery top is wet, however it will be pretty minimal. Just be sure to that no baking soda gets inside of the battery cause it will neutralize the electrolyte (acid) in the battery. Thouroghly rinse and dry the battery top afterwards and coat the terminals with a good corrosion prevenative spray. Hope this helps.
A non-rechargeable wet cell battery.