I feel the appropriate place for this will be the Exide thread & probly the Amara Raja thread. Anyways, I was also looking for some valuation perspectives & approached @harsh.beria93 
for the Same in case of Amara Raja as below :-
On similar lines, my 2 cents on Exide valuation : -
Earlier case with Exide Life
- I valued batteries standalone business on earnings multiple basis separately & insurance part as a multiple of embedded value : -
Pretax operating earnings of last 2 yrs. = 974 crs. discounted to 10% CoC minus 2% perpetual growth rate gives 974*12.5 = 12175 crs.
Insurance business at 2 times embedded value i.e - 2711*2 = 5422
Investments conservatively valued minus Insurance business = 1000 crs.
Total = 18597 crs.
Post Exide Life case : -
HDFC paid 2.5x EV; so net that out & rest remains the rough valuation.
My main concern regarding both the battery manufacturers is regrdng thr mgmt & that’s stopping me frm taking the position apart frm the business aspects.
Disclosure :- no investments as of now in Exide or Amara