Hey all

Went out to the car last week and she wouldnt start just ticking a bit , found battery at 10.7v , it had a ford sticker on it , so im guessing its the origional battery . So i ordered a new one , fit it and all seemed ok. Went out this morning and it wouldnt start again , the wife noticed the little light under the driver wing mirror to be on and the side light drivers side to be on . Also when i tried to lock it the mirrors didnt close inwards. So i went into the car and took the lights off auto and onto off. Car the closed properlyt and hey presto , the car also started . But i cant get this to replicate. 

 

I took some voltages just after turning off the car and closing it letting it go to sleep :

13.53pm - 12.64v

13.54pm - 12.63v

13.55pm - 12.62v

13.55pm - 12.61v

13.5pm7 - 12.60v

13.57pm - 12.59v

14.00pm - 12.62v

16.40pm - 12.50v

 

That seems like a sharp drop to me on volts in a very short space of time , considering it should be at aaround 12.7v on rest , i had some crocadile clips leads coming for my multimeter tommorow , so can hopefully find a parasitic drain  , but has anyone every come accross anything like this before ?

 

Ford focus 2015 titanium X 2.0ltr , start stop

 

also to add , whilke running the alternator is supplying around 13.5v to the battery , does that seem a little low ?

 

New battery was fitted yesterday , and showed 12.7v before i put it in the car .

 

TIA

4 hours ago, tonydb said:

That seems like a sharp drop to me on volts in a very short space of time

That actually is exactly the correct amount of volt drop in the time frame. It discharges exponentially and will start to level out at around 12.45V after which it will slowly drop over a few days.

4 hours ago, tonydb said:

considering it should be at aaround 12.7v on rest

A battery disconnected from a vehicle and fully charged will not be more than 12.65V after 12 hours. The battery contains 6 individual cells, each one is 2.1V With the battery connected to the vehicle and a typical standby current draw of 30mA it will discharge down quickly at first.

4 hours ago, tonydb said:

also to add , whilke running the alternator is supplying around 13.5v to the battery , does that seem a little low ?

The vehicle is equipped with a variable smart charging system. At a fast idle (950rpm) the usual vehicle voltage will be approximately 13.95V but this will change depending on the state of charge of the battery and also what equipment is in use at the time.

hi 

 

Thanks for that , i have just learnt about the "smart alternator" and it made sense why im getting those voltages.

 

The battery was down to 12.44v at 19.55pm

 

Ill see what i can find out tommorow as something was definatly draining the battery this morning!