Power answers for Pakistan.

Yes. The code is laser-etched, and re-etching a cell is a cheap, routine service in the trade — roughly a dollar a cell, less in quantity. A used or downgraded cell with a fresh code will scan correctly. That is why a scannable code proves only that someone put a valid code on the cell, not that the cell is new.

Ask the seller for the batch test report and check it against the cells. A real report lists every cell individually with measured capacity, internal resistance, voltage and serial number. It is far harder to fake than a code because it is long, specific, and you can verify it against the cells in front of you.

One row per cell, with measured capacity in Ah from an actual discharge, internal resistance in milliohms, open-circuit voltage at test time, and the cell serial. The numbers should vary slightly from cell to cell. Identical values down the whole column mean the report was typed rather than measured.

Three checks take two minutes. Look for natural variation in the numbers. Confirm there are as many rows as cells in the batch. Then pick a cell at random, read its serial, and find that exact row in the report. If you cannot match it, the report does not belong to those cells.

Yes, as a first pass. A missing safety valve, a ground-off mark or a code of the wrong length will catch a careless fake in seconds and costs nothing. Just do not treat passing them as proof — it means the cell is not an obvious fake, not that it is new.

Yes. The report tells you what the seller measured; your own bench tells you what arrived. Check resting voltage across every cell, internal resistance on a few against the report, and run one full capacity cycle if the order justifies it. Do it before the cells are welded into a pack.

It is a stabilizer that corrects voltage with silicon switches instead of a relay or a servo motor, so nothing moves to correct the voltage. There are two types: SCR (thyristor), which switches transformer taps electronically, and IGBT (inverter), which builds the correct voltage with fast switching. Both are silent, fast and have no contacts or brushes to wear out.

For homes, shops, clinics and workshops up to about 20 kVA, yes in most cases. It reacts in milliseconds instead of seconds, has no motor or carbon brush to wear, and is silent. A servo still makes sense for very large and three-phase loads, where it gives the most kVA for the money and handles heavy motor starts well.