Ford Mondeo (2011) 2011 Zetec Tdci

pedlowk1 · 14-09-2021, 01:56 PM

Hi Folks,
I am a newby hoping to get some useful advice.
I am a Mondeo owner and very happy with the car. about 2 months back I started having a battery problem. I would park, switch the engine off (radio on) after about 5 mins get a low battery warning. Then the radio would be shutoff. I have had the battery and alternator checked and am assured they are ok.

rondeo · 15-09-2021, 07:02 AM

https://www.fordforums.com.au/showth...1449262&page=2

See post #37.

That should be done when the battery is replaced. If not, the theory is that the BMS determines that the battery is older than it really is and turns off loads to ensure reliable starting.

The BMS system aims to keep the battery at 80% full charge, ie you lose 20% capacity right there. Low battery warning is a common issue on these cars, but they usually seem to start OK. Unless the battery is really low...

NZ XR6 · 15-09-2021, 09:08 AM

It probably means the battery is on the way out. If you are doing mainly short trips, the battery may not be receiving enough charge to stay at 80%. If you still get the low voltage warning after a decent drive, it might be time to think about replacing the battery.

Changing the battery is a job that is better planned than done on the side of the road at night.

cobrin · 15-09-2021, 10:50 AM

Yeah three ways to go from here, first is to go to a battery shop and have a free battery scan done on yours you should get a report or evidence of the results. You'll know if it requires a simple charging, or the capacity is below threshold to save and thus require replacing.

Second, buy a battery charger and charge the battery, things should be back to normal, however you still don't know what capacity is left in the battery (see why a battery report is the way to go), so you might be up for another battery 12/18mths from now. At least you have a battery charger and can do top up charges monthly as a preventative maintenance behaviour, till it simply isn't reliable enough, at least that'll give you time till you need to buy another.

Third, buy a new battery and things should be normal.

Every time the battery warning came up on the dash, the wife always caused it. Left the key in the ignition on pos1 overnight is the main cause, others simply because she'd still be on a phone call over BT in the car every day for 10/20mins after shutdown. Lastly short drives to work and back with no weekend or monthly drive to stretch its legs.

rondeo · 15-09-2021, 03:31 PM

Could be Covid battery syndrome

I'm using a battery charger with a clockwork timer to charge for half an hour a day to make up for losses if the car is not being used.

I used to get the low battery message even with a new battery.

Since resetting the BMS there have been no warnings.