"I need a source of 10A charging a 12V x 10 Ah battery."
A 10 Ah battery (amp.hour) should not be charged with a 10 A source. The 10Ah specification indicates the capacity of the battery, i.e., it can supply a current of 10 A for one hour or 5 A for two hours , etc. For charging, check the current that the manufacturer indicates, usually much lower, and use a current source for the indicated value.
