Hello I own a Ford Fiesta ecoboost 2014 checked my battery voltage and it charges at 15v sometimes a bit above just wondered if anyone else’s charges that high looking into a new alternator because auto start stop doesn’t work it charges that high all the time also doesn’t get up to temp don’t drive it like a nutter change gear at 2000 revs and only do 60mph just wondered who else has this problem 

The battery terminal charging voltage must be less than 14.7 volts otherwise gassing can occur.

the ford smart charge system can go above 14.7 volts for short periods of time under correct conditions. however, if it is constantly charging above 14.6 volts with ambient temperatures above 5c than that indicates a fault. try fully charging the battery with a charger suitable for stop-start vehicles. once fully charged stitch the ignition on for 10 seconds press fog light switch 5 times then hazard switch 3 times battery light will flash to confirm. this resets battery monitoring system if stop-start still does not work and charging voltage is still sitting above 14.6 volts then something is wrong with the charging system.

Agree, reset the battery monitoring and see . 

5 hours ago, cjay1 said:

the ford smart charge system can go above 14.7 volts for short periods of time under correct conditions. however, if it is constantly charging above 14.6 volts with ambient temperatures above 5c than that indicates a fault. try fully charging the battery with a charger suitable for stop-start vehicles. once fully charged stitch the ignition on for 10 seconds press fog light switch 5 times then hazard switch 3 times battery light will flash to confirm. this resets battery monitoring system if stop-start still does not work and charging voltage is still sitting above 14.6 volts then something is wrong with the charging system.

Thank you for your help I’ll give that a try 

15 hours ago, iantt said:

Agree, reset the battery monitoring and see . 

How do you do this?

11 hours ago, Chlorob said:

Thank you for your help I’ll give that a try 

Do you have the standard battery in the car or have you changed it?

3 hours ago, sgalla said:

How do you do this?

Cjay1 has already posted up how. 

how & where is the voltage being measured , and with what equipment ?

you'd be surprised in the variation / accuracy in readings.......

😉

Fit a Class A or B Amplifier from the 90's and a sub, will definitely bring down the voltage