Battery charging theory

[JonnyCJ]

Can any kind chaps enlighten me as to the charging process for a standard battery on a QPV.

My christmas tree lights come on every morning after approx 5 miles and despite going in to the local specialist 3 times and spending a lot of money changing things, it's still happening.

They have said quite flatly "it's not the battery" and it was replaced approx 12 months before I got the car by the previous owner.

I do 12 miles every day to work and the same back, so am wondering if the battery is never getting a chance to fully charge ? Even on the odd run of an hour or two would there be sufficient current provided by the alternator to give it enough of a boost ?

I've stuck it on my CTEK charger, but it's only a 0.8, so ok for maintenance up to 110 AH but really only for batteries up to approx 30 AH for real charging. Needless to say I have now ordered a CTEK 5.0 Test & Charge jobby which looks as though it should be able to do the bizzo.

I'm hoping that it is a duff battery and if so will plug the car in every night after fitting a new one, but would like to understand how things work with the car/battery/charging for future reference.

Cheers

Jonny

 

[2b1ask1]

Nav-Trac (tracker) on the car? These are often still in the car but no longer used or required by insurers so they get forgotten about and their secondary battery keeps pulling a charge and eventually dies, the tracker itself keeps squawking away thinking the car is stolen because nobody is listening to it!

 

[JonnyCJ]

Yep - Nav Trac fitted ! Can it be disabled and would it throw up error codes if the secondary battery was dying ?

 

[2b1ask1]

Apparently you can contact Nav-Trac and ask them to remove/disable it and they should do so for free (others on here have had this service). I just got on an removed mine myself with a deep swallow! I didn't get any errors but for me it involved removing the entire boot lining and the GPS/Antennae remians under the parcel shelf.

 

[2b1ask1]

Sorry, re-reading your reply; no I wasn't getting any errors but it was killing my battery in a few days by the end. Not a single battery problem since

 

[JonnyCJ]

Thanks - very helpful !

Anyone got contact details for Nav Trac or can adise on the process ? had a quick google to no avail.

 

[JonnyCJ]

Updates on batteries. The battery was stuck on the CTEK for 36 hrs and fully charged. I drove to work as usual, but had everything turned off that would drain power (radio etc) and I got another 4 miles or so before the christmas tree lights came on again. Popped out at lunch to a battery specialist and they tested the battery as being fine, with a healthy 12.88v reading and all other things that they can come up with on their fancy tester.

They did however identify that the alternator was only chucking out 13.9v and apparently it needs 14.4v to do the job properly ?

Question is, if the alternator isn't fully charging the battery, but the battery has been fully charged by other means, could this cause the error I'm getting ?

Cheers

Jonny

 

[TridentTested]

Question is, if the alternator isn't fully charging the battery, but the battery has been fully charged by other means, could this cause the error I'm getting ?

I'm no electrician but I'm guessing it could. Modern cars put such a demand on batteries that if the alternator isn't fully healthy the battery will run down in normal driving.

 

[hodroyd]

The alternator will push out a voltage, then that is usually regulated by either internal means in the alternator, or by a voltage regulator on the car, these can go faulty and either give high or low voltage, both not good for the car overall..!!

 

[BennyD]

Mine charges at 13.8v and, I believe, is the correct figure. The regulator controls the output and if it fails you can boil the battery, which is what happened to mine at Le Mans. It sounds like you have got a drain but, personally, I don't think it's your alternator which is, by the way, a b!tch to change.

 

[hodroyd]

If you think it is the NavTrak that is draining your battery, which is possible, they can be contacted at: Cobra Telematics UK

 

[JonnyCJ]

Yep - thanks Hodroyd, Cobra are coming to remove the Nav Trak next week.

 

[hodroyd]

They can either remove it, leave it in as you own it but disconnect it, or replace the darned battery connected to the thing which is usually the culprit..!!

 

[drewf]

Are they charging you to remove it?

 

[JonnyCJ]

Are they charging you to remove it?

Apparently not ! Might just get it disconnected in case future owners want it.

 

[drewf]

That's fair enough - I removed mine, and it's ridiculously easy if you know what to look for, and where to look. It's not marked up with a big sticker advertising what it all is though

 

[JonnyCJ]

Yep - thought of doing it myself, but couldn't be bothered ripping the car apart to find out where it was and then putting back together again.

Happy for someone to do it for me for free !