Peugeot 5008 2011 1.6 HDi Engine Stop Start Fault

Hi! I checked Peugeot 5008 1.6 HDi 2011 with stop start fault! I popped in my friends garage on way to my home and he asked me to look at this Peugeot he got to replace the battery! After they replaced the battery (for stop/start) the customer was complaining that stop/start does not work and also triangle light on the dash. I used his laptop with Diagbox V7.57 and came in fault finding with 1 fault code : P1A9C-Energy accumulator state of health faulty (in engine ecu only)! I have looked everywhere to reset it but can not find it except in parameters I can activate forced start stop for 10-20 km then fault goes away and came back!
Please help!
Thank you.

Regards
kmpg