New battery showing 12.2/3V

[MickDowy]

Hi all, last week I had a battery replacement installed (identical to previous) 60A - 600 EFB.

Checking with a decent multi meter I expected to see around 12.6 or 12.7V, but it only shows 12.2.. or 12.3..   under idle load it go's to 15.3 and 12.5 at 2500 rev's.

Must admit I was expecting a 14.8 ish charge at higher revs ?, the strange thing (to me) at higher revs around 3000 it drops back to 12.5.

I have read about the "dreaded" drain but would have thought a brand new battery could fight that off, but 12.2/3V ???

Could it be the default 80% restricting SOC ? I've read a few people increasing to 90 or 95% on Forscan, but being quite new to Ford & Forscan (only had a look around so far) I wouldn't dare to;  could that 80% be the reason.

Does the battery V monitor on Neg post simply go with what the charge V is, 80% or 90% or is it "fixed".

 

[Eric Bloodaxe]

1 hour ago, MickDowy said:

Could it be the default 80% restricting SOC ? 

Very probably. Fwiw mine shows 12.3-12.4v at rest, 14.8-14.9v when idling. 

My usage is fairly low and irregular these days, so I give it a full cycle with a smart charger every 5/6 weeks or so. After that, resting voltage is around 13.3v, but it drops back to 12.3v or so within days, even when the car's been driven every day.

At around 12.3v it's pretty hit and miss as to whether things like start/stop or interior lights will work.

My previous Mk 8 was just the same.

[MickDowy]

Thanks for your reply Roger, it really is crazy when the the battery (even a brand new one) is basically hovering around 80 - 70% charge, with certain functions becoming intermittent  or not even available.

I am going to use my Topdon 200 battery tester and get a proper report on SOC, CCA & charging value.

Just not happy with things.

[Eric Bloodaxe]

2 hours ago, MickDowy said:

Just not happy with things.

Your'e not the only one, as you'll have seen from the many threads on here.

I find it very annoying that my wife's 10 year old car which only does 1500 miles or so per year, is still on the original battery (and key fob battery!) yet gives no bother. Progress, eh?

[StephenFord]

11 minutes ago, Eric Bloodaxe said:

I find it very annoying that my wife's 10 year old car which only does 1500 miles or so per year, is still on the original battery (and key fob battery!) yet gives no bother. Progress, eh?

I was going to chip in with similar info! Mums Toyota Yaris (2003) Hasn't had a battery in over 15 years, and during lockdown, didn't go out for 4 months, it eventually started on 1st twist of the key. Of course it's old & Japanese, so hardly a good comparison for a modern Ford 😂

[Eric Bloodaxe]

59 minutes ago, StephenFord said:

Of course it's old & Japanese, so hardly a good comparison for a modern Ford

Sadly, from what I've seen in the 12v battery thread (2,500+ posts) in the Yaris forum, it's probably not a good comparison for a modern Toyota either! 

[Paulkp]

7 hours ago, MickDowy said:

under idle load it go's to 15.3 and 12.5 at 2500 rev's.

I do not know a lot about Smart Charging, apart from the fact that it isn't !

But would it charge at a higher rate when engine is not propelling the car, and at a lower rate if it thinks the engine is working hard ?

[StephenFord]

2 minutes ago, Paulkp said:

I do not know a lot about Smart Charging, apart from the fact that it isn't !

But would it charge at a higher rate when engine is not propelling the car, and at a lower rate if it thinks the engine is working hard ?

Here's the instruction manual for one should you feel the need to investigate 😁

Maypole-Smart-Charge-MP7423-6V-12V-4A-Instruction-Manual-July-2018.pdf

[Paulkp]

Thank you for your kind offer, but I'm yet to read the instructions for my Davenset.....

[TomsFocus]

I misread that as a forum for Dave's!

 

[nicam49]

It all depends how long the battery has been in stock.

When I bought a new one from ECP (Duracell brand) it took a good charging from my battery charger to get it up to 100%

[Tizer]

4 hours ago, Paulkp said:

I do not know a lot about Smart Charging, apart from the fact that it isn't !

But would it charge at a higher rate when engine is not propelling the car, and at a lower rate if it thinks the engine is working hard ?

It does sometimes depending on what Charging Mode the PCM decides upon and it is even worse than that, it can not charge at all, which means that it is discharging at quite a high rate when under load and only charges on the overrun.

When in Conventional Charging Mode, It charges conventionally though.