Battery Charging (Fiesta Mk7) - keep system connected?

[jerrydf]

HI,  I need to charge a flat battery on a Fiesta Mk7 (2009).  Do I need to disconnect the rest of the system to charge the battery, or can I just attach the charger to the battery? If I leave things connected, is there an issue with ecu, etc?  If I disconnect are there issues with alarms, etc?

Thanks for any help

Jerry

 

 

 

[st line x 140 driver]

Charge with battery in situ that's how chargers are designed to be used.

[jerrydf]

Thanks Simon.  That's what I used to do years ago, I was just unsure about the higher complexity of more modern systems.

 

[st line x 140 driver]

If you buy a more expensive one you can jump start the car from them even with totally flat battery. All you have too do then is find out why your battery is flat.

Most car batteries have a shelf life of 5 years which is the same as there guaranty 😁 Diesels suffer more as they tend to have a higher compression ratio therefore need more powerful/heavy duty battery with high amp hour.

Cold weather causes voltage drop hence car not starting or harder to turn over. Winter months take more toll on batteries as they tend not to take so much charge as you are driving with lights, heater etc on all the time. Another reason why start stop function always fails this time of year.

[Bobr]

I put my battery on a trickle charger occasionally and just connect to the battery as usual.   Never had a problem.

[st line x 140 driver]

9 minutes ago, Bobr said:

I put my battery on a trickle charger occasionally and just connect to the battery as usual.   Never had a problem.

That's another option Bob - if you are going to have charger connected all the time in the winter months may as well just have an electric car😜

[jerrydf]

This is in my wife's Fiesta, a 2009 1.6 TDI, battery is ~3 or 4 years old. The car hasn't been used at all since Covid started except for the occasional trip to keep it turning over, and als for the MOT. 

Are there any special procedures for my 2015 Focus?  It has stop/start, so I presume it is an AGM  battery.

 

[jerrydf]

Thanks Bob!

Electric car - there's a thought. My son's thinking about one of them

[TomsFocus]

I find petrol batteries suffer more in the cold...manufacturers fit puny little batteries to them due to lack of glow plugs and CR...  battery on my 2.0 TDI looks like a suitcase for a weekend away!

In car charging is fine, just make sure to connect the leads in the right order or even better switch on the charger after connecting.  There is a small possibility of spiking electronic systems, especially the audio screens, but most people get away without any issues.

if you do decide to disconnect the battery, there should be no issue with the alarm and no radio codes on Mk7.  Just need to reset one touch windows if you have them.

Edit - Regarding your Focus, you may need a different charger for a stop start model.  My battery charger isn't compatible for SS.  The battery is most likely EFB rather than AGM.

[Steveostit14]

I just use my old trickle charger from the 1980's leave it over night ! Still works a treat

even gets my start /stop to work for week or so,!! Just connect to positive and negative 

terminals, disconect nothing, never had a problem after.

[st line x 140 driver]

4 minutes ago, TomsFocus said:

I find petrol batteries suffer more in the cold...manufacturers fit puny little batteries to them due to lack of glow plugs and CR...  Battery on my 2.0 TDI looks like a suitcase for a weekend away!

In car charging is fine, just make sure to connect the leads in the right order or even better switch on the charger after connecting.  There is a small possibility of spiking electronic systems, especially the audio screens, but most people get away without any issues.

if you do decide to disconnect the battery, there should be no issue with the alarm and no radio codes on Mk7.  Just need to reset one touch windows if you have them.

Always remove negative lead first to prevent sparking.

[TomsFocus]

Just now, st line x 140 driver said:

Always remove negative lead first to prevent sparking.

And blow across the battery if in a confined space like a garage.  Make sure there's no gas build up to ignite if there was a spark.

 

[st line x 140 driver]

5 minutes ago, TomsFocus said:

And blow across the battery if in a confined space like a garage.  Make sure there's no gas build up to ignite if there was a spark.

 

never heard of that on but hydrogen gas is very combustible, good job i gave up smoking😁

[jerrydf]

Thanks everyone.  That's all welcome advice.  My charger claims to be ok for AGMs, although I'm hoping to keep the Focus moving a little more than the Fiesta. I know about resetting the windows - done that before, but hopefully I'll keep the battery connected.