I agree with what Dhwanil has said. A quarter is definitely a very short period to assess the performance of any company and in my opinion, even a year is not long enough for a company which operates in a duopoly.
We should take a 2-3 year view on Amararaja. The operating margins are steadily improving over the years. There could be a GST tailwind when at least a certain percentage points of market share moves from the unorganised to the organised sector. This coupled with the soft lead prices which are not being passed on to the after sales customers is also helping in margin expansion. There is no telling which way the lead prices would go, but continued softness in lead prices is a reasonable bet to make.
This company is a classic case of having the ability to absorb huge amounts of capital at high rate of returns. The duopoly nature of the market in all probability will ensure that there is no senseless price war hurting both Exide or Amararaja in terms of returns.
A certain amount of growth is also assured with the increased sales of both the four wheelers and two wheelers. There could be ups and downs as automotive is a cyclical industry, but the secular growth in India can be assumed for some years to come.
Therefore all the right ingredients are there is place for this company to give reasonable returns in the future.
Please listen to Q3 concall of Exide. The management didn't see the better Q4 results coming. Either they were trying to downplay the improved performance of Q4 or they were clueless. Given the performance of Exide management in the last few years, i would bet on the latter.