if i have voltage source equal 15v , I want charge battery 12 v ( maximum voltage equal 12v for battery) , can charge ?

 

Yes but you will need a suitable circuit to control the volatage and/or current to match the charging requirements of the battery and the maximum current 15V source can provide. The details of that circuit depend on the chemistry and specification of the battery.

 

The voltage matters very little as long as the supply voltage exceeds the battery voltage. What matters is the current. A 30V charger that can only supply 100mA might be safer for your battery than a 15V charger that can supply 50A.

Go to Battery University to learn more.