Help please

[Szade79]

Hi all I have just bought and fitted a new battery for my c220 CD and it worked fine for 5 days but I went to start my car and it was totally flat, I have tried jump starting it it tries to start but as soon as u disconnect the jump leads there is absolutely no power there again any ideas
Tia

 

[Tony Dyson]

Check your alternator is outputting a charge voltage of between >13v <14.8v

 

[DREAMER NO2]

Your battery is flat again so first step is to recharge the battery . Over night it will go flat if regulator is no good .. Could be that the alternator will just need a new regulator . But as above post from Tony get a check on output from the alternator first. Also is the battery light on before you start the engine ? and going off after it starts . Also both of the posts on the battery must be making a good contact ,remove and clean them up grease each one and replace it . And i dont like jump starting any car ,,you can cause problems for yourself .

 

[Blobcat]

Regulator failing can flatten a battery overnight