U141100 Battery terminal recognition Open circuit... Bad battery?

larbel

Registered User
So, starting last night, the door handle sensor stopped locking and unlocking, had to use the remote to unlock and lock, and engine started normally and instantly, but a dash warning says "Electrical system: Low battery, battery will charge when driven" or something like that briefly and everything back to normal, and door handle sensor would work if I stop engine and lock it right away, but if I wait like 5 mins or so, the sensor won't work, does this look like the battery is charging but dropping voltage rapidly?

It's a 1.5 yrs old Varta EFB battery, I never use Start/Stop. Scan came back with U141100 Battery terminal recognition open circuit, and battery is at 13.7x with engine running and 12.1x with engine off, does this sound like a bad battery or should I have the alternator looked at? Thanks!
 

AlS3BE

Registered User
Looks like a bad battery to me. If it was alternator then you wouldnt get about 14v when engine is running.
Modern starters can start will low voltage unlike the old days when that was the tell tale signs of a bad battery.
If you only do short journeys it might be worth shoving the battery on a slow charger over night to see if it helps. Or try and claim on the warranty, varta batteries has like 5 or 7 year warranty.
 

Jcbmally

Started with nothing & still have most of it left.
Not wanting to sound a bit ignorant but open circuit usually means "no connection" as in broken wire or damaged/blown fuse.
Are all the battery leads connected/undamaged.
 

larbel

Registered User
Not wanting to sound a bit ignorant but open circuit usually means "no connection" as in broken wire or damaged/blown fuse.
Are all the battery leads connected/undamaged.

Yup, first thing I checked, everything seems normal at the battery, and I don't believe there's a fuse for the battery itself?
 
G

Guest

Guest
13.7V across the battery terminals with the engine running is far too low. An alternator should be charging at 14.2/14.5 V . A fully charged battery will sit above the 12.1 V you have, more like 12.5 V. 12.1V is heavily discharged.

JS
 
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larbel

Registered User
13.7V across the battery terminals with the engine running is far too low. An alternator should be charging at 14.2/14.5 V . A fully charged battery will sit above the 12.1 V you have, more like 12.5 V. 12.1V is heavily discharged.

JS

Meaning it could be alternator issue rather than battery?
 

AlS3BE

Registered User
13.7V across the battery terminals with the engine running is far too low. An alternator should be charging at 14.2/14.5 V . A fully charged battery will sit above the 12.1 V you have, more like 12.5 V. 12.1V is heavily discharged.

JS

13.7v could be just tick over revs. Give it some revs and if it doesn’t rise above 14v then maybe look at the alternator.
 
G

Guest

Guest
Meaning it could be alternator issue rather than battery?

It looks like that to me. The car is accurately reporting the fact the battery is in a low state of charge, so alternator is a suspect.
JS
 

AlS3BE

Registered User
Bring the revs up to 2000 and see if it hits about 14v+ that will tell you if it’s alternator. If you are measuring with the car just ticking over it’s not going to be on full charge.
 

larbel

Registered User
Car's at idle when measuring... Should go over 14v if bringing it up to 2000. So as long as it's 14.x at 2K above, it should be battery?
 
G

Guest

Guest
Car's at idle when measuring... Should go over 14v if bringing it up to 2000. So as long as it's 14.x at 2K above, it should be battery?

Yes, should be 14.2/14.5V at an engine speed of a couple of thousand revs/min. Just a thought, are you using the car regularly?

JS
 
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