current is in Amps..usually from 4A to 25A charging rate,
Voltage is V in the range of 180-220Volts..
i am guessing what he did was change the OUTPUT voltage from the default 208 to 224Volts.. that is the voltage given back to the house in case of loadshedding.
1 - Your voltage out has nothing to do with charging rate
2 - you probably have the 2200VA XL model.. this model has default low charging rate of aprox 10-14amp.. by connecting it to PC and enabling Boost charging in software the rate can be increased to near 3000VA model, which is exactly what your guy did.
3 - the 3000VA model has by default the charging rate of 20 amps, so it doesnt need enhancements.
4 - shoukat and others who have the SUA1500i cannot have enhanced rate of 20Amps.. i have the same ups at home,.. the problem is the design of the UPS. the SUA are small home user UPS who have 1 single transformer for
both charging and AC/DC conversion... the XL have 2 seperate tansofrmers for each job. and they are designed to work with external battery packs so they have boost charing option which the SUA doesnt have. SUA have default charging rate of 5Amps. which is why Shaukat faces charging time of many hours. this can only be enhanced to max 7-8amps, which is still too low for our lite situation..
5 - however the solution to SUA problem is in external chargers. extensive experimentation and countless hours lead to eventual high powered custom made external charger.. details can be found here
now it takes 1.30 aprox to charge fully from dead to full..2x 130AH.. backup of 3-4 hours on lights and fans..1.5 hours with TV.
for any further questions please contact me via PM..