First of all, the battery car won't recognize the brand of the charger.
The factors that affect it are one voltage and two currents.
The replacement charger should have the same voltage as the original 48v and 48v,
Charging current, the charger is generally in accordance with the battery capacity size, equipped with 8-10 hours full charge principle, the first is the output is 1.8A current, 1.8*10=18ah battery, the second charger is 4820 charger, the charging current of the two is very close, completely can be used.
However, the lead-acid battery charger cannot be interoperable with the lithium battery charger, remember.