2005 Fiesta - new battery

[100SRV]

A year ago I fitted a new alternator to a 2005 Fiesta, and the guy I happened to mention this to told me that when fitting a new battery I'd need to carry out a reset process so that the alternator didn't overcharge the new battery.

A year later on and I've fitted a new battery but can't find any reference to a reset process in the owners manual or haynes workshop comic.

The alternator has a CAN connection so it's plausible that the body ECU monitors system voltage and controls the output.

Measured Volt drop between alternator output / battery and alternator case / battery - both in <10mV
Alternator output is 1.42 V and no sign of dropping after a few minutes running.
Old battery has good electrolyte levels but struggled on very cold mornings.

Was I mislead about the reset process?

[GreenV8S]

I assume that refers to resetting the BEM, but I thought that would only apply to cars with stop/start systems. Does your car feature stop/start?

[cuprabob]

100SRV said:

A year ago I fitted a new alternator to a 2005 Fiesta, and the guy I happened to mention this to told me that when fitting a new battery I'd need to carry out a reset process so that the alternator didn't overcharge the new battery.

A year later on and I've fitted a new battery but can't find any reference to a reset process in the owners manual or haynes workshop comic.

The alternator has a CAN connection so it's plausible that the body ECU monitors system voltage and controls the output.

Measured Volt drop between alternator output / battery and alternator case / battery - both in <10mV
Alternator output is 1.42 V and no sign of dropping after a few minutes running.
Old battery has good electrolyte levels but struggled on very cold mornings.

Was I mislead about the reset process?

I very much doubt a 2005 Fiesta requires any coding or resetting when fitting a new battery. I assume you mean the alternator output is 14.2V.

[vw_99]

Never seen that year of fiesta needing a battery coded.
On the "mk6" fiestas they did run a smart charge alternator. Similar to modern cars with a BMS.

On MK6 fiestas if a battery goes flat it can cause problems with dash and abs units.

But never heard of a battery needing coded.

[100SRV]

Thank you, yes I did mean 14.2V
No stop start on this 2005 car &#128521;