So... my reading of the battery voltage before starting yesterday were incorrect, new readings as of today:

Before starting after stood overnight around 11 hours, 10.4v
Straight after starting charging at 15.4v
After drive into town and back of about 40 mins 14.3v

Tonight i will disconnect the battery and see if it drains down to the same 10.4v hopefully this will identify it is only the battery and hopefully i dont also have something draining the charge after switch off

The easiest quick test is a load test - can be done with headlights & cranking. If the car has a fault and pulling excessive load there may be a 'crack' or visible spark when disconnecting/reconnecting (not the safest test if recently been charging). A clamp ammeter may indicate this but you'd need to have a base load from a good vehicle to compare with, unless it's a big load which then would be obvious.

After a quick google I found this which might interest - https://www.2carpros.com/articles/car-battery-load-test
I would be monitoring the voltage when applying load to see if it drops drastically.

One things for sure, you are at high risk of damaging your alternator if the battery is goosed. Then you've 2 things to buy  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

cheers for the reply!
I found a chart on here that indicates the acceptable figures for a sport of that year after the car goes to "sleep" checking that with a clamp is the next port of call, my father is the sparky in the family and is currently away so im just pottering about with what i can at the minute.

I did have the battery disconnected the other day and there was no spark when re-connecting, simple method but never thougt about that little test!

the battery load test is intersting although i may hold off on that one jsut yet as if the battery completely dies im knackered, the other night i had the lights on while having the fault reader plugged in but engine not running and in about 5 mins the battery lost 1v not sure if this means anything or is typical of something such as headlights taking that ammount of power.

EDIT: definately dont want an alternator to add to the list! ill disconnect it today and see if it drops to the same 10.4v after around 11 hours then new battery will be on the cards tomorrow.

You need a new battery anyway. 10.4V is entirely discharged which just about the best way to kill a car battery. I would bet on there being a dead cell in the battery. Replace it now before you your alternator. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

battery is currently off the car and has been for about 6 hours and is currently sat at 12.6v would this not suggest the probem is something draining the battery rather than the battery itself? dont want to buy a new battery for it just to loose charge down to 10.4v again
thoughts?

EDIT: later im thinking re fit battery lock the car down let it go to sleep and measure to see if its pulling any amps by disconnecting the negative and bridging it with a the multimeter

update:

Battery left for 10 hours off the car went fom 12.59v to 12.55v

connected it to the car and instantly dropped to 10.4v also when it was connected before keys were inserted into the ignition the radio/cd player was whirring away almost sounded like it was trying to eject a cd

double locked the car and let it go to sleep (20 mins) i then tested for anything draining the battery and it was draining at a rate of 0.6a removed f22 (rear heater blowers) and it dropped to 0.3a
removed f26 (air suspension) and it dropped to 0.2a

Thoughts everyone?

My thoughts are that dropping from 12.55v to 10.4v just by connecting to the car tells the battery is goosed, it would need to be a high load to pull it down that much on a good battery which I suspect you would definately know about when connecting due to the crack/spark, I wouldn't even expect the engine cranking to pull it that low on a good battery.

Also if fully charged then it should sit at a much higher voltage for a long time. 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

cheers insiorc, there was actually a little spark when connecting although im positive there wasnt when i did it the other night. another interesting observation, i pulled the fuse for the rear blowers seen as this seemed to be pulling about 0.3a after switch off, car started fine then after a drive i turned it off went back out about an hour later battery was still at 12.6v and started fine not a single error message (gret! i thought) however after returning home that night i turned the engine off and checked the voltage to see what it was at, the "follow home" lights were on at this point anf the voltage was dropping significantly then when they went out it continued to loose 0.1v a second! down to about 11.8v.
I checked thismorning and again it was dropping at 0.1v a second down to about 10.4V this seems it sat at 11.8v all night then as soon as i unlocked it and got the meter on the battery i observed he dropping. so if itll sit overnight and not loose voltage id asssume if there is a remaining bettery drain on the air suspension as i cant really pull that fuse, it must be minimal and the battery is the main cause and doesnt deal with any load very well.

might give that load test a go today that you reccomended earlier, ive borrowed a charger and currently got the battery charging now.

W18ODY wrote:

ive borrowed a charger and currently got the battery charging now.

ah unfortunately not they were all after a run which as i've read doesnt quite charge the battery properly.

ill give it a full charge and carry out the load test described in the link you posted yeterday, perhaps the 2 small battery drains im experienceing are being exagerated by the fact the battery isnt truly fully charged and as it is quite probably goosed.

cherers.

EDIT: battery has charged very quick showing fully charged and is holding 13.04v currently? only been on charge about 40 mins or so is this normal?

W18ODY wrote:

EDIT: battery has charged very quick showing fully charged and is holding 13.04v currently? only been on charge about 40 mins or so is this normal?

As a rule of thumb from a flat battery of 12v you divide the battery aH rating by the charge amps, so a 100aH battery takes 10 hours at 10A charge. So your 40 minutes would need a serious charger to charge that quick, in itself probably destroying the battery.

It's  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

thst was my thoughts, im pretty uneducated with the electrical side of things so thought id best ask.
what do you make of my theory regarding the battery drains been exagerated becasue of the weak battery?

In my limited experience with batteries, if it’s quick to charge, it’s quick to discharge.

I’ve just got a 60% off discount code for GSF. I’ve no ideas if they’ve hiked up the prices to compensate but worth a look for a new battery.


 2019 5.0 SC SVA (Current)
2012 5.0 SC AB. Sadly written off by a campervan
23 plate Focus ST (Current)
1942 VEP Ford GPW Jeep (Willys) (Current)
1943 Whites M16 Halftrack (Current)
16 plate Eurofighter Typhoon, 2 x Eurojet engines with 20,000lbs thrust each. 1380mph

Britplumber that sounds like a pretty good theory to me!

Cheers for the code!! ill pop on the site and have a look

My last battery would charge fine with my Ctek but then would go downhill almost straight away when asked to do anything.

The problem with checking it after driving is that the plates develop a surface charge that your meter picks up - battery looks charged. The surface charge dissipates slowly. You leave it overnight and that surface charge dissipates resulting in the "flat battery in the morning only" effect.

A new battery is £100.  2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed