Day 13 of ownership: dead on the driveway this morning - it started, generated dozens of faults as soon as I moved and then everything went off/blank/dark/silent. Stone dead battery. Fortunately it had died right next to Mrs A’s car so a jump-start got it running but with lots of bongs, an unlit dash display and more warnings on it than I thought possible.

One lift to Halfords for a new battery, one battery swap in the rain and all is well; starts immediately with no errors. Relief (that the jump start hadn’t damaged anything)! But… the battery I took out was only three years old and my GAP tool then shows me that on idle the system voltage is 11.7v and at 1800rpm it’s still only 12v.

Should I have bought an alternator instead?

Last edited by Mike_A4 on 14th Jan 2023 4:02pm. Edited 1 time in total

Get a volt reader on the battery directly mate and make sure it's sending out the same voltage as what gap is saying but I'd say likely hood is its an alternator job

For your reference, I fitted a new alternator a few weeks ago, and at idle I get 13.7-14 and as soon as revs are applied or when driving 14.7.

Those look more like the values I would expect.

I don’t know which is most irritating - the needless expense of new battery or the imminent expense of a failed alternator.

Oh well. Back to workshop this week and another weekend of not using it.

Last edited by Mike_A4 on 15th Jan 2023 1:17pm. Edited 1 time in total

Facelift models have a 'smart' battery charging system which varies the charging voltage depending on load so if you are not seeing a constant 14.7v it's normal 2012 TDV8 Vogue (L322)

Exactly - don't rely on 'traditional' charge voltages being present all the time for pretty much any vehicle designed & built in this century, in certain circumstances, you can see system voltages of 12.6VDC, which is 'as intended'. 11.7VDC definitely points to a defective charge system, interesting that your starter battery was flat, that usually points to a defective rectifier pack, personally I'd recommend that you disconnect the battery to prevent it being over-discharged like the one you replaced (which would probably need replacement as well as the alternator anyway). you may also detect the alternator giving off some heat, even with a cold engine.

[sigh]

It’s been in the workshop since Tuesday morning, although they really only got onto it this morning as it was an un-booked task and they’ve been fully committed. Three hours into the task of changing the alternator – and, although it’s dismounted, it’s still trapped in the engine bay. Has anyone removed a TDV8 alternator? If so, what else had to come out to clear a path and what route out did you take?

I did note previous comments, thank you; I didn’t answer because I was hoping to have it all solved by now.

I don’t appear to have the smart-charge system even though it’s a facelift model, something I’ll regard as good. I did check for an uncontrolled load by unscientifically checking the voltage recorded by the tracker. Over 30 hours it dropped by 0.07v, which is hardly uncontrolled. When I drove to the workshop, the existing 12v voltage dropped to 11v and stayed there, only rising to 13v when they moved it into the workshop for initial diagnosis on Tuesday morning and put it on charge.

Monday, they hope, and all will be well.

Is this a dealer? they should be well able to remove the alternator! I've done a fair few on the 4.4TDV8 in the past and don't remember anything too onerous about it.

RE: unscheduled work - tell me about it, I've two BEV's needing batteries replacing, a rear traction motor to swap, a timing chain replacement and a powertrain removal to replace a bearing cap in the gearbox... all breakdowns on top of the normal workshop loading for me.

Take a look at this thread on alternator swaps- https://www.fullfatrr.com/forum/topic23089...alternator Got - 2017 SDV8 Autobiography in Loire Blue
Had- 2008 TDV8 Vogue SE in Java black
Had - 2007 S/C in Stornoway Grey

I have it back – at last!

Nearly six hours in total, he only billed me four since that what was he quoted. He didn’t seem overly impressed by the faff, but I think he’s suffering from a turnover of mechanics and is therefore missing out on workshop memory. Denso unit fitted with a two-year warranty, so add that to the new Halfords battery with a five-year warranty and I hope that’s the end of low voltage issues for the duration.

Incidentally, the IID tool voltage reading at idle now reads 13.5v.