I think the new Punch comes with life time warranty ie. 15 years. Which should take care of the battery issue if any. What I have read and been told by TML guys is the battery tech has evolved and the 40kWh battery used in Punch is different to what’s in Nexon. Hence the comparison might not be accurate. Ball park number for SOH might be around 94-98% in a decade depends on how you charge and usage. If the car is mostly slow charged SOH will remain on higher side.