L322 Battery flat for no reason

So yesterday I drove 100 miles round trip to the shops (boring)
This morning drive my 3 miles to work,
Get back this evening to a completely flat battery, wouldn’t even turn it over a little.
Had my jump pack in the boot (this ain’t my first l322 rodeo, I may not have the sense to buy a Volvo but I do learn to be prepared)
Did my 3 mile journey home, check the battery and it’s showing 12.2V I’ve left it on charge and hopefully it’ll get me through the week
I’ve checked on the icarsoft diagnostic and it’s running 13.2 V on tickover and 13.6V at speed. The battery is just under a year old and a high quality battery and hasn’t given some any reason to be concerned in that time.
My question is do I need a new battery a new alternator or is it likely I’ve got a parasitic drain somewhere?

I wonder if 13.6 is a little low, my 90's alternator gives out about 14.5 above 2500 rpm.

Try this .. start the car, running at tickover and turn the headlights on. If they're dim, or go dim after a minute say, rev up and see if they increase brightness. If they do increase brightness it's probably not your alternator, or it's probably not charging enough at lower revs! If the headlights stay the same as normal running and don't change much when revved then charging is probably OK overall and you need to get the battery checked.

I'd do that test after you've been for a drive, not directly after charging the battery externally!

If you test it and it's inconclusive tke it to 'Kwik Fit' or other 'garage' and get the battery/alternator properly checked.

I wouldn't use Kwik fit personally ...

Could be alternator, usually its 14.1v ish for a good one, i believe on the L322 it should be even higher than that.
Also if the diode fails in the alternator it can drain the battery pretty fast.
First stop (as it costs nothing to do) should be to inspect alternator wiring, battery terminals and earth straps.

I’m not getting any dash lights but I guess it hasn’t failed completely if at all,
Maybe I’ll try with a multimeter instead of relying on the diagnostic kit,
All the connections look good
Is there a way to find out exactly what output I should be gehtting from the alternator? I did expect 14+ but this is a Land Rover after all

Ok so got the multimeter out this morning, running with nothing switchable on 14.4V
Heater and stereo on 14.1V and that plus lights 13.9V
Would that suggest the alternator is ok?
I’m thinking maybe it’s got a drain, but must be quite a big one to flatten the battery enough in 8 hours to not turn over the engine.
I went through the stress of finding a parasitic drain on my old l322 but can’t for the life of me remember how I did it.
Any thoughts as to the best way to initially find out if I have a drain? In the back of my mind I remember taking off the negative terminal and then it’s a blank from there

Being careful to follow the battery disconnect procedure it’s a case of tricking the passenger door and boot into thinking they are closed when they are not, connect ammeter between the negative terminal and a good earth and then when it’s gone to sleep you can disconnect the earth lead from the chassis by the battery leaving any current flowing via the ammeter. If you have a reading then it is a case of pulling fuses until the current drops. You will have a few mA but can’t remember what is acceptable. Sometimes just unplugging a fuse and putting it back could wake it up again.
I’ve never tried this method personally but it makes sense to me..
If you have headlamp wipers they can be a culprit as can final stage resistor.
I don’t know if the charge voltage should remain at 14.5 volts with everything on.

Alternator output should be 14.5 to 14.7 at 2k rpm regardless of what you switch on. 13.9 volts will not fully charge a modern lead calcium battery.

Think that could be your problem, I guess it could be the alternator draining your battery also

holidaychicken said:

Think that could be your problem, I guess it could be the alternator draining your battery also

Click to expand...

The alternator can certainly drain the battery if a diode fails in the diode pack.

So I swear it’s done it just to fry my brain but car started perfectly well this morning and again this evening,
I’ve set the aux heater for 5.15 in the morning as starting early and to put a bit of strain on the battery to see if it plays up.
Gotta love the green oval !!!!!!!

How old is battery ? Many modern batts have 3-5 year warranty if you have a receipt..

But definitely check the condition with a proper tester, and battery disconnected from car. The L322 electrics do impact the test.

Check the car goes to sleep properly. I found one with dodgy bonnet switch that woke the car up randomly due to winds lifting the bonnet a few MM.

Battery is under 12 months old, tested ok with a drop tester, not amazing but ok which I guess is.... well... ok
It appears to go to sleep but haven’t had time to properly check,
My old l322 had a slightly loose nut on the blow off valve, only found it by mistake, had stumped a technician for 2 days as it only woke the car up with a good breeze

Over the years I have found when having a battery tested if they come back with its ok just needs a good charge the best thing to do is replace it because its on its way out anyway.

Yeah I’m thinking that, especially when it’s still under warranty, if they will replace it!!!

youmitegetian said:

Battery is under 12 months old, tested ok with a drop tester, not amazing but ok which I guess is.... well... ok
It appears to go to sleep but haven’t had time to properly check,
My old l322 had a slightly loose nut on the blow off valve, only found it by mistake, had stumped a technician for 2 days as it only woke the car up with a good breeze

Click to expand...

The trouble is, if you leave a Lead Calcium battery in a poor state of charge, they fail very quickly and as your alternator is not putting out the voltage needed to fully charge the battery, it's quite likely that the battery is on it's way out.

I found out I had some "issues" after having my car washed by a different person... Stay with me here...

The interior lights were occasionally staying on or coming on while driving & hitting the odd pot hole.

Anyway, red herring time... I thought it may have been the latch micro switch because pulling at the top gate would switch the lights off.

However, after much head scratching and many many red herrings, it turned out to be the wiring to the lamp on the tail gate. However, I'd removed the useless 1/4 watt lamp and replaced it with some LED's for a better lighting experience. They were perfect for over a year & a half, but somehow the water must have created a short and the rest of the interior lights were affected.

Anyhoo, after scratching my head till it bled, I decided to poke the wiring in the hole left by the now removed top tail gate lamp.

Wow! Issue solved! I ended up cutting out the spade connectors & soldering the wires & heat-shrinking the joins.

Result is no more lighting hilarity and no more flat battery.

But worra pullava

Anyhoo, not suggesting this is your problem, but you'd be surprised what a drip of water can do to systems that need a fraction of an amp to "wake" the BECM

check your earths

Hi all,

Having been off line for some time due to various reasons won't bore you with, I would like to agree with the sentiment above, check earth straps to the engine. My 4.2 spent months off the road due to constant battery drain only to find it was one earth strap doing the damage. Once sorted she has run faultlessly ever since.

Good luck and please let us know the outcome.

Tricky.

As an extra thought to all the above, when checking earths, if they look dirty, or corroded, don't bother cleaning them, replace them! Well worth it in the long run ..