Hi! I Recently both a Mercedes 2010 s400 the issue was a missing  power control module ! So I buy one from China for 1800 dollars I make sure everything was disconnected before Processing for installed the power electronic model, after I checked the very useful write up i start assembling everything and connected my maxi das ds808 and clear all the codes I got one current and stored 0C7800 the precharging time of the high voltage on bord electrical system is too long! I couldn’t erase it I checked all the connections it looks okay , the on bord voltage should be between 48 and 150 Mines read 15 V only, I asked the guy who I bought the part from he said the hybrid battery need to be activate, when I ask him how to? No response, I tried everything with no luck, I hope you guys can help me out 



It seems that the charge status of the hybrid battery has reached 0%. Once the charge level drops below the 15% level, the vehicle will no longer charge it. 

It is possible to charge these batteries but that procedure is very complicated and also they were not designed to be charged. 

You will need to get the battery replaced, unfortunately. 

Hi Faisal,

My story is almost identical to yours, including the part coming from China, including the exact same error code. Have you managed to find a solution?