The battery earth is bolted to the inner wing, and there have been instances of them coming loose

Thanks Andy K

Do I need to move the battery out and is behind the fusebox or is it one of the 3 bolts on the wing situated in front of the battery and fuse box? Or Am I completely way off  RRS SUPERCHARGED, 22 INCH ALLOYS, JAVA BLACK, FULLY COLOUR CODED
EVERY POSSIBLE SOFTWARE UPDATE INCLUDING - BLUTOOTH UPDATE, SATNAV ON THE MOVE, CLOCK ON DASH, 3 CLICK FLASH, GEARBOX RESET, COMPRESSOR UPDATE AND SUSPENSION LOWERED,
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Behind fusebox.

No not the 3

Is it accessible without moving the fuse box or do I have to remove the fuse box out of the way, if so any recommendations to how? RRS SUPERCHARGED, 22 INCH ALLOYS, JAVA BLACK, FULLY COLOUR CODED
EVERY POSSIBLE SOFTWARE UPDATE INCLUDING - BLUTOOTH UPDATE, SATNAV ON THE MOVE, CLOCK ON DASH, 3 CLICK FLASH, GEARBOX RESET, COMPRESSOR UPDATE AND SUSPENSION LOWERED,
BLACK CODE RE-MAPPED, AUTOBIOGRAPHY'D, NEW EXIDE BATTERY, NEW DENSO ALTERNATOR

I think you just need to remove the battery

So Ive found were the battery negative wire bolts onto and looks like i have to remove battery and also move the fusebox but while I had the battery cover off I thought id check the battery again with the multimeter and its seems ok again charging at 14v and also 14v with a full load including lights, fans, heated seats its still keeping up charging 14v so now im really confused as I havent changed anything

Any ideas why it doesnt work one minute and now working perfectly??? RRS SUPERCHARGED, 22 INCH ALLOYS, JAVA BLACK, FULLY COLOUR CODED
EVERY POSSIBLE SOFTWARE UPDATE INCLUDING - BLUTOOTH UPDATE, SATNAV ON THE MOVE, CLOCK ON DASH, 3 CLICK FLASH, GEARBOX RESET, COMPRESSOR UPDATE AND SUSPENSION LOWERED,
BLACK CODE RE-MAPPED, AUTOBIOGRAPHY'D, NEW EXIDE BATTERY, NEW DENSO ALTERNATOR

I would stil clean all the earth straps and check all tight, as if intermittent it suggests something loose / corroded

360 wrote:

I would stil clean all the earth straps and check all tight, as if intermittent it suggests something loose / corroded

It's actually one of the easiest preventative things to do on a car as over time they 'will' corrode, it's just a matter of when. I've made a 20+ year career (non vehicle) chasing earth/grounding problems which with fancier electronics are more susceptible to the problems caused by poor connections. Just for the sake of adding a smear of copper grease, preferably to a split connection then re-coat after connecting.
Also if there are any exposed spade connections like switches/sensors underneath then do them aswell, but if there's a concern of short circuiting then choose a dielectric grease - I usually coat my trailer and caravan light connections with this stuff which prevents corrosion at the bulb and other connections. Just slap it on as it has several thousand volt insulation.

And top tip - DON'T abuse that old favourite WD40 - I've had it smoking in my apprentice days when trying to dry out an explosion proof light fitting which had filled with water so I was trying to dry out the terminations (yes it should have been isolated...). I learnt quickly that it is not electrically isolated liquid as I was frantically wafting the smoke fumes away from the fire & gas detection systems nearby which if set off would have probably lost me my job!
And for the record, WD40 is as a penetrant/release agent, but people still keep using it, even experienced technicians... 13MY Range Rover Sport Autobiography SDV6 - mine
14MY Range Rover Evoque Dynamic SD4 Black Pack - wife's
99MY Defender 90 TD5, Soft Top Conversion - my toy, and bairns favourite

B9BS X wrote:

So Ive found were the battery negative wire bolts onto and looks like i have to remove battery and also move the fusebox but while I had the battery cover off I thought id check the battery again with the multimeter and its seems ok again charging at 14v and also 14v with a full load including lights, fans, heated seats its still keeping up charging 14v so now im really confused as I havent changed anything

Any ideas why it doesnt work one minute and now working perfectly???

The alternator will charge at an higher rate for the first 3 minutes after start up and then drop back to lower volts, it will also charge at an higher rate in winter when very cold, hence the 15v plus voltage rates reported. The only accurate voltage check is with a multimeter across the battery terminals.
You have checked the battery to body earth, but have you checked the body to engine earth and the alternator connections?
I regularly get over 15v in winter but in summer 13.8/9 is the norm.

For what it's worth my dad , who was someone I held as very knowledgeable on all things mechanical and electrical used to say a battery (lead acid) shouldn't be charged at higher thank 14.5 volts so if I've got one on the bench I stick to that rule .

Interesting but I've got a problem with my hayabusa at the moment which could be its regulator playing up , but with the battery at 13.5 volts when not running it goes to 14.4 with meter across on high revs but I suspect when it's hot this voltage may go over this

If you have the suspension fault etc. coming up are you sure you haven't got a drain from something?

A 1amp drain will kill your battery in 4 days and on these can cause the warnings to come up within 24 hours if you have not been on any long runs.

The draw should be around lower than 0.1 ideally.

So many of these seem to draw over .5 amps which is too high, and loads are pulling close to an amp.


I have just been through this with my FFRR, turns out it was the TMC module in the boot, mine was pulling 0.9amp and a new battery would start to lose it capacity in weeks, then once it did the faults would show on start up nearly every day.


Got the mulitmeter out and started pulling fuses and testing the alternator, realised it was the TMC unit, unplugged it and bypassed the most loop and now pulling 0.02 amps when it goes to sleep.



I'm sure this has been discussed loads on here, but just in case anyone sees this post I will put basic testing below.



To test for parasitic drain you need to put a multimeter into amp mode and put it in parallel with the cable, positive or negative, but I always use negative, only because if you do accidentally touch the chassis or something it doesn't matter, far safer.

The multimeter needs the positive set to the amp socket as seen below.....

Then set it to 10a, it may be 5a or 20a, but set to the highest first and then move down to more sensitive readings if you get nothing, so 20 first, then 200, then 2000 etc. but 99% of time on these 20a or whatever will be fine.

I open all the doors and bonnet, then push the catches shut so the car thinks they are closed, then put something heavy on the bonnet catch.

You can test before the car goes to sleep, just before sleeping it is usually reading 6amps or so, but you can still pull fuses and note any big drops. But you really want to wait till it sleeps. Mine goes from 6 volts to around 1 something and then after 23 minutes drops to 0.02amps. So be patient and wait 25mins before panicking.




To test the alternator for parasitic drain, they fail a lot on TDV8s.
Undo the big red cable that runs to the charge point on the bulkhead, then place the multimeter cables between the cable you have removed and the point it was attached to. This should read 0amps.
If it doesn't your alternator is faulty and causing drain.

To test the rest of the car undo the negative terminal, battery or bulkhead is fine, and put the the multimeter between them.

Let the car go to sleep and see what your drain is. I would say anything about 0.25 is too high and needs sorting.

If it is higher than simply go through the fuses pulling each one out and seeing how much the amps drop, for me it was the bluetooth and TMC unit that was causing issues. The bluetooth I knew was dead, but being left in caused drain, the TMC unit I can't see why that was causing it, but pulled it anyway.
Down from 0.9-1.1 amps to 0.02-0.04amps when asleep.

Battery has gone from causing issues after a couple of days to he point where it can be left for a month or more with no problem.