Hi all,
I have recently been having some battery issues on my 2011 TDV8, namely the low power warning when watching TV with the ignition off, FBH not firing up etc. I assumed either a battery drain, old battery or alternator issue.

This week I replaced the battery (following the excellent thread https://www.fullfatrr.com/forum/topic43662.html) with an Excide 019 AGM. Turns out the old battery was date stamped 2017 and probably needed changing anyway. I borrowed a neighbors GAP IID to reset the battery. This was only partially successful as my car wasn't registered to the tool and so I only got limited information screens. I then put the battery on a smart charger which reached 13.3v. On returning to check the battery 30 mins later it read only 12.3v on my voltmeter.

Next day I ran the car on a 30mile journey and watched the battery output (not entirely sure where this is measured) on the hidden '753' screen which was at approx 12.3v while driving at 70, but rose 13.3v when decelerating. Not what "i was expecting. With the ignition off the battery read 12.3v. Having had a few concerns about a battery drain I decided to remove the only DVD loaded, which had come on at some odd times. I also tried a quick drain test using my clamp meter after waiting for 30mins for everything to shutdown and got a reading of between 100 and 70 mA.

Next day I did a 50mile drive the alternator seemed to be working differently and more like what I expected. Now the reading was 14.3-14.6v for most of the first hour, which I assumed was about right as it was trying to charge a partially charged battery. On the return home the battery vales dropped to around 12.7v and that was the reading I got with the ignition off.

This morning the battery reads 11.8v!!

So I'm now wondering

1) Have I got a duff new battery?
2) Is there an alternator issue?
3) Have I got a battery drain?

This morning I was going to tackle the battery drain issue using a Sealey TA120 fuse tester (https://www.amazon.co.uk/Sealey-TA120-Automotive-Current-Tester/dp/B001SBFZK0/ref=asc_df_B001SBFZK0/?tag=googshopuk-21&linkCode=df0&hvadid=232061105168&hvpos=&hvnetw=g&hvrand=4774849009276840153&hvpon
e=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006476&hvtargid=pla-447271968231&psc=1) following this thread (https://www.fullfatrr.com/forum/topic47332.html). I fell at the first hurdle trying to manually lock the car by being unable to remove the small cover off the passenger door handle. Is there some sort of knack to removing it.

I would really appreciate any advice of which issue to tackle first and how to proceed.

Phil

Hi all
Last evening I disconnected the earth lead and put the smart charger on the battery. After 5 hours the charge had reached 13.2v and i disconnected the charger and left the earth lead off. In the morning, with the car left unlocked overnight, the voltage had dropped to 12.9v. After reconnecting the earth lead (with the BMS) the voltage immediately dropped to 12.3 volts.

I then started the car and I reset the battery again using my neighbors GAP IID and the process cycled thru various screens and seemed to be successful. the engine was running for onkly 5 minutes.

I then sat in the vehicle with everything off and watched the shutdown on the Gap. Initial voltage was 12.6v and dropped to 12.5v after 30mins. At this point the system had still not gone to sleep with the Battery quiescent High Range reading 2.61A and the low -30mA. I was expecting the High Range would have dropped to near zero as it should only take 20mins for the system to close down.

Phil

A couple of thoughts...


It's a smart charging system and only gives what is needed, quite often it will not charge the battery fully, the engine will start with a voltage lower than you think...

Telling the car it has a new battery is advisable but doesn't make that much difference it will learn what the new battery wants without it...

Leave it alone for a while and see what happens, you may find it is working fine, if not, then is the time to go looking...  Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Firstly, a clamp meter (unless one designed for low current & extended use) isn't an ideal way of measuring quiescent current as the reading will drift, secondly, the voltage measurement will be entirely charge level (as Haylands points out) and temperature dependent.

Are you experiencing any low voltage issues? are there any DTC's stored? Why do you think there is a problem?

Not having the vehicle locked means it's not shutting down fully - also a reading of -30mA isn't plausible unless you had a charger connected so your current measurements are not reliable - unless you did have a charger connected.

Start with the basics, what is the problem/concern, what are the symptoms, what have you changed & why?
Every week I see vehicles with issues that haven't been resolved or understood but customers or tech's have changed parts without any real diagnosis, just a 'need' to replace something to address the issue.