stop start battery voltages

[Dazza007]

Altransit will suggest the batteries Ford fits are silver calcium and not good for stop start, which too may be another valid point

What I've noted, from reading up on the subject, is that you really need AGM, or at least EFB, batteries for stop-start to work properly, because they're better able to maintain full starting current, even when partially discharged.

Having said all that, I duly fitted a brand new EFB battery in the Focus, to see if the stop-start would start working more reliably than it had, with the Silver Calcium battery that I had previously fitted. I would have fitted the superior AGM battery, but not only are they more than double the price of an EFB battery, but they don't come in the correct size to fit the battery tray

Any road up, even with the new and correct battery fitted, it still hardly ever works

Thanks for the reply, If my battery is only keeping upto 12v of charge will removing it and trickle charging it over night bump it up or is it knackered? its probably the original battery so its 6 years old now. If Stop/Start saves around 5% diesel then over a year it will pay for itself with the mileage I do.

[knobby1]

Thanks for the reply, If my battery is only keeping upto 12v of charge will removing it and trickle charging it over night bump it up or is it knackered? its probably the original battery so its 6 years old now. If Stop/Start saves around 5% diesel then over a year it will pay for itself with the mileage I do.

It's 6 years old...it will be shagged.

Lord Knobrot

[loot]

6 year old battery these days is probably below spec for stop start on your van, I know the bcm is quite thirsty generally.
Battery wants drop testing

[Dazza007]

What's the best brand of AGM battery for a 2.2 tdci? If I fit it how can I tell the computer its a new battery?

[Dazza007]

For future readers of this thread you cannot get agm batteries for the transit because of the height of them. They won't go in the space.

Back to the voltage's issue, I tested both batteries after the engine had been off for 5 minutes, both were 12.4v. Last time one was 14v before I swapped them around. Have I got a charging issue, thoughts welcome.

[dumper]

Checking will a volt meter will no tell you a lot you need a heavy load tester on it and some times they will say battery is ok and they are not

[blue estate]

For future readers of this thread you cannot get agm batteries for the transit because of the height of them. They won't go in the space.

Back to the voltage's issue, I tested both batteries after the engine had been off for 5 minutes, both were 12.4v. Last time one was 14v before I swapped them around. Have I got a charging issue, thoughts welcome.

did you check them as soon as you turned off the engine ?
My money is still on dying batteries

[Dazza007]

I checked them as fast as I could, getting out, pulling seat forward, setting multimeter up etc etc. they are both near identical now about 12.4v. Does anyone know how the S/S system worls on these vans? On modern cars they stop at TDC and the alternator or generator or a combination of both restarts the engine whiuch tends to be much smoother but if im guessing right its only the starter motor that works and it seems quite crued. If it stops at TDC then it might be worth buying 2 batteries for longevity of the starter motor.

[Dazza007]

yesterday I decided to bite the bullet and bought 2 new batteries from General Traffic, Yuasa 80ah's with 3 year warranty, my old batteries were running at 14.7 v but the new ones are running at 13.4v, is this normal?

[loot]

My stop start is very random at present, original Ford batteries.

I bought 2 bosch s4 110A ones last time for my mk7.

Yours are probably a bit crud at 80A?

My stop start won't come on until it is happy with power and even the heater on etc stops it.

[Dazza007]

I think the originals were 75ah so i would have thought the increased amp hours will make it better. Also, why dont ford tell you its unavailable like my car does. When you swapped the batteries did they tell the computer it has new batteries or does it figure it out itself? and would having a OBD2 bluetooth dongle, a dashcam, a tablet and a phone on charge stop it working? between all devices its prob only 5 amps draw.

[loot]

This is the eternal question lol.

I've only had ss on this vehicle and tbh i can take it out leave it, it does it now and again. I don't know the actual specifics regarding the strategy but I know that it has to be safe so lights etc on in winter and I'd expect it not to work at all.

Imagine if it had priority and you broke down due to having flat batteries because it ignored low voltage? Someone broke down in the middle of nowhere and attacked our something to boot. Fook me the world would go mental, we're always trying to be green but I think it is a case that it shouldn't take such priority that human life is put at risk.
This similar to srs, they aren't that easy to actually set off.

You can try a pcm update, undo the extra items and no lights or other items then a motorway drive with the new batteries.

Did you check if the speedo settings allowed you to turn ss on /off at the wheel?

Mine didn't work for months and months but when Ford did the software update the van came back with ss working.

[v8dave]

I checked them as fast as I could, getting out, pulling seat forward, setting multimeter up etc etc. they are both near identical now about 12.4v. Does anyone know how the S/S system worls on these vans? On modern cars they stop at TDC and the alternator or generator or a combination of both restarts the engine whiuch tends to be much smoother but if im guessing right its only the starter motor that works and it seems quite crued. If it stops at TDC then it might be worth buying 2 batteries for longevity of the starter motor.

I've posted this before in various forms with the reason why you do it.

To get a good idea of whether your battery or batteries are good.
1) turn on the ignition but not the engine,
2) heater blower on full, headlamps on, if you have it heated screen on
3) wait five minutes
4) now measure your voltages

If you have twin batteries but no stop/start the starter battery should have disconnected after about two minutes.

Alternately get them drop tested by an auto electrician.

Batteries have a very large surface area on their internal plates and this acts as a capacitor as well as a chemical cell.
Putting as reasonable drain on the battery for a few minutes empties the capacitor effect so that you then get a reading of the chemical state of the battery with your voltmeter.

[Dazza007]

Thanks for the reply, Im not sure what you mean by the stop start will disconnect after 2 minutes. What am I looking for here?

[Altransit]

Thanks for the reply, Im not sure what you mean by the stop start will disconnect after 2 minutes. What am I looking for here?

If you have twin batteries, when you switch on the ignition a relay will connect both batteries together for starting. If you don't start it and leave the ignition on, then the relay will disconnect within 2 minutes, to prevent the starter battery being drained.