Replacement charger must have the same output values (volts & amps) as the original, plus the connector obviously has to physically fit the input connector on the laptop (they are not "one size fits all"). The connector's centre-pin must also be the same polarity as the original one (ie positive or negative).
Battery voltage is nothing to go by because the charger is also an AC adapter - - it has to be able to power the laptop direct from the mains socket as well as charging the battery.
Since I assume you no longer have the original charger from which to get the output values and pin-polarity, your safest bet is to google for a battery charger for your specific laptop model.