My battery had a dead cell in it and I had too drive it for a month, during this time it just died going down the

Your vehicle may die going down the road due to a battery that is not able to take a charge. The reason is that the charging system is not meant to provide full needed electrical power to operate the vehicle while the engine is running. It is meant to recharge the battery. The battery is supposed to sustain the proper electrical power needed to operate vehicle components with a stable output of reference voltage. The alternator does typically put out proper voltage, but this will fluctuate based on engine speed. Of course, once you get a proper battery in the vehicle, you'll have to do further testing to find out if other concerns have developed. You must have a good battery in the vehicle before embarking on any other testing.

ANYTIME battery power is lost - so are vital engine operating strategies that can certainly caus engine stall... As well as low engine rpm - to the point the alternator can not keep producing sufficient voltage output. REPLACE THE DEFECTIVE BATTERY!