Mk 3 Mondeo battery discharging

Bawnmore

Hi folks - having some trouble with battery discharging on a 06 2ltr TDCi Mondeo. Happened for the 1st time on Thursday just gone, and a few times since.

On Thursday after a 30 minute drive while pulling into a parking spot, the battery light came on. Once I had turned off the car, I tried to turn it back on again and the battery was dead (turning slowly - not even close to starting). I didn't have jump leads on me, so went and bought a set, but when I came back it had just enough power to start. Had to move and park once more that day for a hospital appointment and exact same thing (wouldn't turn on immediately, but had just enough power 1 hour later when back).

When I got home, I replaced the battery with another fully charged battery to see if it would drain this. Drove 30 mins, and same again. In this case, I jumped the car and it got me home, but the battery light (and ABS light) was on towards the end of the journey.

I replaced the battery with charged battery again, cleaned the connections on battery and cars + and - leads, added some vaseline and replaced. Same again.

I feel like it must be the alternator, but have a few things I thought I'd run by here before I can get a hold of mechanic on Tuesday:

1. After some research, it seems like these cars need a silver calcium battery to work correctly with a smart charge system used. I bought a new battery around 3 weeks ago from a motor factors and gave the cars reg to get the right battery and this is the one they gave me - an Exide Excell EB712. After a quick look I can't find anything that says it's a Silver Calcium battery. Would this be an issue?

2. If the alternator wasn't charging the battery while driving, would the battery light not be on all the time? Currently, it comes on only once the battery is fully drained.

Bawnmore

Just to add to this, tested voltage at different states and reading:

- Car Off: 12.9
- Car On with no electric load: 14.05
- Car on with loaded electrics (headlights, AC, heated back/front windscreens all on: 12.28

I'm assuming that suggests it's not getting enough electricity on load which is what's causing the battery to run down. This makes sense, as every time it's run down it's been when the heating and/or lights would have been on during the run. When it went fine yesterday during a few runs during the day, the lights/heating/radio wouldn't have been on.

Would this point towards the alternator needing to be replaced?

whizbang

This has started happening only since you got a new battery 3 weeks ago ?

Double check all connections from Alternator to battery, remake all earth connections, and check all fuses.
It sounds like something silly..

martinr5232

Bawnmore wrote:

- Car Off: 12.9 - Car On with no electric load: 14.05 - Car on with loaded electrics (headlights, AC, heated back/front windscreens all on: 12.28

Dont test it with heated front screen on it draws too much current to get an accurate reading.

Bawnmore

whizbang wrote: »

This has started happening only since you got a new battery 3 weeks ago ?

Double check all connections from Alternator to battery, remake all earth connections, and check all fuses.
It sounds like something silly..

Checked just now out of interest and battery was bought exactly 4 weeks ago. Trouble started out of nowhere last Thursday, so not sure if it'd be related to new battery.

Could definitely be loose connection between alternator and battery though - I'll check these this evening.

Dont test it with heated front screen on it draws too much current to get an accurate reading.

Good to know - what's best to have on to test under load? Head lights/AC/radio?

case_sensitive

Check simple things like corroded earth straps; usually to your gearbox or suspension strut, I had that on mine a while back.
https://c2.staticflickr.com/8/7532/29549633896_fa1026484c_b.jpg
If the alternator is working, which it seems to be, and your battery has a full charge (~12.8v) then it could be that the battery no longer has enough 'oomph' (Cold Charging Amps) to do the hardest job; turning the car over.
A battery place will test your car for free with one of these gizmos; mine is a Foxwell BT100, ~€45 from Amazon.  
My 159 used to suffer from parasitic battery drain, so I got it to see if the battery had suffered from being frequently discharged (it had, I replaced it with a monster 710CCA one).  Taken this am, car been sitting for a few days.
https://c1.staticflickr.com/5/4536/38209622351_935f4e7bde_b.jpg

Bawnmore

Just to update on this, I got a mechanic to check it and it was the alternator that was the problem. Had it reconditioned and picking up today (after a false start with a 2nd hand part). Hopefully should be all sorted by tomorrow. Will update here after.

Bawnmore

To round this one out - reconditioned alternator did the job. Back in action. Auto electrician mentioned brushes were shot, and he replaced the bearing while he was there.

case_sensitive

Bawnmore wrote: »

To round this one out - reconditioned alternator did the job. Back in action. Auto electrician mentioned brushes were shot, and he replaced the bearing while he was there.

Dare we ask what the labour charge to replace the alternator twice was? 😱

Bawnmore

case_sensitive wrote: »

Dare we ask what the labour charge to replace the alternator twice was? ��

Local guy who's very reasonable. Charged €90 for labour including the replacement belt he picked up for me. I had €200 in my head as what it would cost and rounded up to to €100.

Alternator refurb was €70.