Battery Experts: ASSEMBLE

[GiT]

Car involved, is a 2021 Ford Puma ST Performace.

It's on its 2nd battery and is only 21 months old, but a synthetic drain has been finally found.

Battery wise, it's a start and stop type, So GEL or AGM.

During the drain issue, the battery got absolutely flattened - it was showing 4.95v at one point. Had to manually enter the car with the old school key.

Battery was fully charged, drain found (finally) but the battery is exhibiting dead cell traits.

Car does a 70 mile run, arrives home and I test it with the engine still running - 14.8v. Perfect Alternator voltage. Stop the car and the battery drops to 12.4v immediately and within 3 minutes drops to 11.9v - where it stays.

My understanding is that it should sit at 12.6v-13v once turned off. But 11.9v tells me that's a dead cell in the battery (Varta) and it's been damaged by the drain and flattening.

Thoughts, folks?

 

[NorthloopCup]

BMWs do the same thing with the voltage unless it’s a lithium battery found in the M power cars.

So I’m saying it’s fine.

 

[GiT]

BMWs do the same thing with the voltage unless it’s a lithium battery found in the M power cars.

So I’m saying it’s fine.

Really? Everywhere I've spoken to locally have stated it should remain between 12.6v and 13v. Local battery warehouse place said at 11.9v, it's toast.

 

[Tom]

It’s fucked.

12v battery tech is absolutely terrible in new cars, they are stupidly sensitive to undervoltage.

what was causing the vampire drain?

 

[R3k1355]

IIRC if they get properly discharged the plates oxidise and can't hold charge properly.

 

[NorthloopCup]

Really? Everywhere I've spoken to locally have stated it should remain between 12.6v and 13v. Local battery warehouse place said at 11.9v, it's toast.

Does it drop down more if it’s stood for a few hours or remain at 11.9?

A battery doesn’t like being totally discharged and can lead to them failing. But if they’re charged back up again fully not long after total discharge, the damage is lessened.

A battery with a dead cell doesn’t just deteriorate over time. They’re like a switch - on/off, so - fine/fucked.

On the BMWs it can take up to 15 minutes for all the control units to power down and go ‘to sleep’, so in that time they’re consuming voltage. Once asleep, the voltage tends to go up to around 12.2v/12.3v.

Going off the information you’ve given in your first post, I’m still saying the battery is fine.

 

[GiT]

Does it drop down more if it’s stood for a few hours or remain at 11.9?

A battery doesn’t like being totally discharged and can lead to them failing. But if they’re charged back up again fully not long after total discharge, the damage is lessened.

A battery with a dead cell doesn’t just deteriorate over time. They’re like a switch - on/off, so - fine/fucked.

On the BMWs it can take up to 15 minutes for all the control units to power down and go ‘to sleep’, so in that time they’re consuming voltage. Once asleep, the voltage tends to go up to around 12.2v/12.3v.

Going off the information you’ve given in your first post, I’m still saying the battery is fine.

It stays there about there (11.8-11.9v). When it was cold (-3') it dropped to 11.59v.

After couple of days inactivity, it is still down at 11.8-11.9v.

 

[GiT]

It’s fucked.

12v battery tech is absolutely terrible in new cars, they are stupidly sensitive to undervoltage.

what was causing the vampire drain?

TCU module. (Telematics)

It was in effect constantly issuing commands / transmitting and the battery was being constantly drained. The car was shutting down it's non-essential processes.

We had it in to the dealership several times and only when I got arsey, did it get resolved.

 

[GiT]

IIRC if they get properly discharged the plates oxidise and can't hold charge properly.

This is pretty much word for word what the Battery Warehouse chap said, along with "You get away with it on an old car battery and more so the Leisure batteries. Not these".

 

[Touring_Rob]

IIRC if they get properly discharged the plates oxidise and can't hold charge properly.

Sulphate

Git, does it start the car?

Lead acid battery has a resting cell voltage of 2.1v. So after a full charge after an hour or so the battery will be at 12.6-12.7v. They can be at 13v straight after charge but won't stay there.

A dead cell would mean the rest voltage was more like 10.5v.

I suspect the plates are sulphated. This happens after a deep discharge. On some batteries it can be fixed by discharging the battery and then re charging it several times. However the charge current should be fairly low, a high current charge from a fast charger it a jump start can damage the battery further.

 

[Touring_Rob]

...

 

[GiT]

Sulphate

Git, does it start the car?

Lead acid battery has a resting cell voltage of 2.1v. So after a full charge after an hour or so the battery will be at 12.6-12.7v. They can be at 13v straight after charge but won't stay there.

A dead cell would mean the rest voltage was more like 10.5v.

I suspect the plates are sulphated. This happens after a deep discharge. On some batteries it can be fixed by discharging the battery and then re charging it several times. However the charge current should be fairly low, a high current charge from a fast charger it a jump start can damage the battery further.

Yep, starts it. It keep flagging up on her screen with a "Start the car or turn off the ignition" once she hops in the motor.

The Yaris, with the same type of battery has never discharged, operated correctly over the last year and shows 12.7v when sat / cold.

 

[Touring_Rob]

Yep, starts it. It keep flagging up on her screen with a "Start the car or turn off the ignition" once she hops in the motor.

The Yaris, with the same type of battery has never discharged, operated correctly over the last year and shows 12.7v when sat / cold.

Good chance it will improve with warmer weather before dying next winter.

But if you want a new battery I can highly recommend this lot: https://www.tayna.co.uk/car-batteri...rnF-_RJLdrdoKWa3jHnDoJ8sM3cFZv5caAvkOEALw_wcB

 

[GiT]

Good chance it will improve with warmer weather before dying next winter.

But if you want a new battery I can highly recommend this lot: https://www.tayna.co.uk/car-batteri...rnF-_RJLdrdoKWa3jHnDoJ8sM3cFZv5caAvkOEALw_wcB

Used them before, are very good.

We want Ford UK to replace it, but if they don't (Ford UK technical have also agreed the voltages are too low), I'm replacing it with a Bosch, and then the old one is going to Varta UK (Manufacturer for Ford UK) for a full report that I can use against Ford.

 

[Touring_Rob]

Yuasa are very decent too if you can't get the Booosh. Good luck!

 

[Rob]

Used them before, are very good.

We want Ford UK to replace it, but if they don't (Ford UK technical have also agreed the voltages are too low), I'm replacing it with a Bosch, and then the old one is going to Varta UK (Manufacturer for Ford UK) for a full report that I can use against Ford.

Alternate idea… phone up another dealership (record it), and state you have the very same car but just out of warranty (ages wise(. State the problem, and see if they suggest replacing the battery. If they do, use that against your own dealer/ford U.K.