Starter Battery (1 Viewer)

[Lazyboy]

I have an "elek-trickle" problem.
Looking for some help/advice please about my starter battery. Parked up for 3 days and the van would not start. Called AA (Nationwide account) who jump started and on our way. The AA guy said starter battery was knackered as showing low voltage before starting and then said it was not taking a high charge when running. Any way, we journeyed home. Since driving about 100 miles home the vehicle has started each time I have tried. It is not on hook up. I have a multi meter. Sounds good, but a bit like giving a penguin a machine gun!!. Anyway.battery at rest is showing 12.8v. ish and with engine running about 13.4v. Does that seem about right? I believe it went flat because I had the dash cam running all the while set until the starter battery went to 12v (Black Vue with Magi-pro). We set the alarm each night and there is a tracker running. I guess that is what goosed the starter batery. I assume that with a "smart alternator" the starter battery does not receive a high charge on tick over or by just revving the engine while stationary.
Is that the best way to check the starter battery with a meter and not disconnecting anything?
Hopefully someone with the knowlege (Lenny HB) may help before I fork out for a new battery.
If I do need a new battery, I am leaning towards a Bosch with a 5 year guarantee/ Good or is there better?

 

[Lazyboy]

@lennyhb are you able to help?

 

[Tombola]

If its is low then it should show more than 13.4 going in.
If the run home charged it though at up to 14v, then 13.4 will be right to maintain it.

You are better to leave it a few hours to rest then check the resting voltage and see how close up to 12.8 it is.

If the AA man said it wasnt taking a higher charge rate 9f 13.8 or more when flat I'd be inclined to believe him and check as above. But keep my eye on it over night.

 

[Raul]

I have a smart alternator, and battery goes to 14.2-14-4v only when engine breaking, coasting, or going downhill. All other times the alternator is off, or when its on it only goes up to 13.2-13.4v max. Thats how smart alternator charges. I do have a dash cam in parking mode when parked up, but also have solar that trickle charges the starter. Many times during start, the battery dips down to 11.9v, and will be 7 years old in december. But still works fine on stop-start.

I meant to say, get one of those 12v that plugs in the cig lighter socket and displays the voltage, it will give you a indication of what's happening with the starter battery.