Early in March I bought a new Multimeter and ran a few tests, the results being

Battery and Charging Tests
March 2023 using Multimeter and Clamp
Battery is 850 CCA
Alternator is 180amp
Battery voltage at rest is 12.6
Battery Draw in sleep state after 40 minutes 18 mA (0.018 on scale) max draw should be less than 23 mA
Under full load everything switched on. 136amps going in from Alternator
Volts 14.58 so Alternator is very good
Cranking Volts drop to 10.66 very good

Hey p_gill,

Does the voltmeter indoor photo plug into the cigarette lighter (or dash 12v output)? Sure beats the hell out of opening the bonnet (hood), removing the battery compartment lid and sticking my voltmeter to the battery terminals in the pouring rain! Zermatt Silver LR2 i6

Previous

1997 Range Rover p38 4.6 V8
2003 Range Rover L322 4.4V8
1989 Range Rover Classic 3.9 V8
2003 Land Rover 90 Td5
2000 Range Rover p38 2.5dHSE
1975 Land Rover 90 SIII 2.25 petrol
1996 Range Rover p38 4.0 V8
1990 Discovery 3.5i V8 (3 door)
1973 Range Rover Classic 3.5 V8 (2 door, ex-Police)

Exactly.

You just plug it into the power port that was designed for a cigarette lighter.

Here is the one that I have.

https://www.amazon.com/gp/product/B00VL9JZ...&psc=1

It is absolutely better than standing in the rain.

Take care

Paul

You'll probably see slightly lower voltage at a cig lighter port, since it's some distance from the battery / alternator, runs though a fuse box and probably one or more connectors, and those lighter plugs don't make the best connection anyway. It should work fine as a reference point, if you compare apples to apples.

That's right about loosing voltage to cig lighter port I loose just over over a volt. around 1.3 v to be precise.

On a different but identical observation to the approximate .10 voltage difference, a few years back I flashed my dash display with Alex's custom SDD display flash which includes real time battery voltage as well as other very useful information. I also use the Torque Pro app with a bluetooth OBDII reader at times which can also provide "real time volts" through the app and OBDII. The voltage at the OBDII reader is ALWAYS approximately 0.10 volts LESS than what's displayed on the dash custom display. IDK what the voltage display would be at the cigarette lighter outlet personally as I don't use mine at all unless I need to recharge a smart phone.

Hi Paul,

Some weeks have gone by with everything function as normal. I bought one of these plug in voltmeters (see pic). Impossible to get them here without at least one USB port

Apart from an incident two weeks ago, the voltage on morning start up, no accessories is 14.2v



After a long trip of 60 miles it drops down to 13.5v.

Only incident was two weeks ago on a dark rainy night. The battery light come on. The voltmeter indicated 12.2v. As I was on a deserted country road I decided to press on to my destination. Within 10 minutes of 40 mph travelling, the battery light went out and the voltage went up to 13.8v.

No problems since. Zermatt Silver LR2 i6

Previous

1997 Range Rover p38 4.6 V8
2003 Range Rover L322 4.4V8
1989 Range Rover Classic 3.9 V8
2003 Land Rover 90 Td5
2000 Range Rover p38 2.5dHSE
1975 Land Rover 90 SIII 2.25 petrol
1996 Range Rover p38 4.0 V8
1990 Discovery 3.5i V8 (3 door)
1973 Range Rover Classic 3.5 V8 (2 door, ex-Police)

14.2 on a cold start ------ perfect

13.5 when the battery is almost full ---------- perfect


12.2 ------ as you indicated that is the problem



A few tips

1. if you are regularly getting the battery up to a full charge (i.e. 13.5 volt from the alternator) then event though the voltage drops to 12.2 you should have enough reserve capacity to drive for almost an hour (possibly more if you urn off everything that you can)

2. the next time that you see the 12.2 pull off the road lift the bonnet and verify that the alternator pulley is spinning. If it is then it is likely time for some new brushes (rebuild the alternator)


Good luck

Paul

Thanks Paul. And if the alternator isn't spinning, is that something to do with the clutch mechanism?
Does that exist? Or is it a direct drive from the ancillary belt?

cheers

Alan Zermatt Silver LR2 i6

Previous

1997 Range Rover p38 4.6 V8
2003 Range Rover L322 4.4V8
1989 Range Rover Classic 3.9 V8
2003 Land Rover 90 Td5
2000 Range Rover p38 2.5dHSE
1975 Land Rover 90 SIII 2.25 petrol
1996 Range Rover p38 4.0 V8
1990 Discovery 3.5i V8 (3 door)
1973 Range Rover Classic 3.5 V8 (2 door, ex-Police)

Alan,

The clutch is attached to the Alternator and the drive pulley is attached directly to the READ.

A small coupling connects the two (you can call it a belt if you like)

The failure mode is as follows. The clutch seizes and then extra forces are placed on the drive pulley which causes it to become loose and then it doesn't spin the alternator. And then the voltage sinks to 12.X volts.


https://www.aulro.com/afvb/freelander-2-a/...owner.html



I suspect that your brushes are worn out and that you have a different failure mode.


Let us know


Thanks

Paul