Thread: Battery charge voltage info poll.

Originally Posted by awabbit6

Tim, are you concerned about the effect of having an auxiliary battery connected? I can give you the readings with or without.
What would you prefer?

No, but both readings would be very interesting, Thanks.

Cheers.

Originally Posted by justinc

(ps did you get my PM Tim? thanks for the help!)

Yes thanks Justin and glad to see everything seems to be sorted now.

Cheers.

I'll be happy to participate ,I will take some measurements of both cranking batteries ie Disco and Rangie and post up the results in morning.

Originally Posted by drivesafe

If any of you have the time, and has access to a digital multi meter, would you like to take part in a simple battery voltage test.

The idea of the poll is to see whether cranking batteries are not being charged above the 70% level that is proposed in quite a few articles or is it more like 90+% the state at which I find most vehicle’s cranking batteries to be at.

There are 10 basic questions and just answering the first will do, but if you have the time and info available, answers to any or all of the other nine would be very helpful in see just how alternator battery charging works in different vehicles.

The info can be from any vehicle, not just your Landy.

The first question will be more accurate the longer the vehicle's motor has been off, preferably 12 or more hours after the motor was last on.

1 ) What is the voltage at the cranking battery’s terminals. 12.8V (2x)

2 ) Type of vehicle. '93 RRC

3 ) What make and type of battery ( a model number will do ) 2 x Supercharge Allrounder 1 x MRV70, 1 x MRV70L dual connected

4 ) When was the last time the vehicle was driven. today

5 ) How long was the last drive 45mins

6 ) Is this your day to day drive or a once a week vehicle Daily

7 ) Alternator size Iskra 120A (actually for a Massey Ferguson!)

8 ) Is this your tow vehicle or other. Tow.

If you can, the following info would also be of interest.

9 ) What is the voltage at the cranking battery when you first start your vehicle ( cold start ) 12.2v @ crank, 13.8v @ idle, 14.5ish @ +1100rpm

10 ) With the motor still running, what is the voltage at your cranking battery after a 30 minute drive. 14.2v.

The last two questions are for gaining a better idea of how different alternator operations. Alternator operation in most vehicles is now controlled by the vehicle’s Engine Management Computer. This independent control not only means that there will be differences in alternator operations between vehicle makes but even between same make and models.

I Had an 03, Mark III Range Rover, first version of the current model. It’s alternator went to 14.3v soon after the motor started and stayed there for as long as the motor was running.

I now have an 08 Mark III Range Rover, the latest version of the current model. The alternator in the 08 RR does not start generating power for about 30 to 50 seconds after the motor is first started and the initial voltage can then be anything from 14.2 to 14.9 volts and does not seem to be influenced by ambient temperatures.

Exactly 30 minutes after the first start, the voltage lowers and can be as low as 13.2v.

For anyone trying to get any form of alternator operations info, it is almost impossible to get any data form any of the manufacturers, so your input can be very helpful.

A suggestion to make the data entering easier to post, copy the ten questions and paste them in a word processor, add your data under each question and then copy and paste into a reply.

Both of mine each have a +ve lead direct to starter motor, a smaller lead cross connecting the two +ve terminals together and an earth lead from batt>chassis>body>engine.
I run A/C, EAS compressor, 2 lightforce, 2 IPF 900's with 130w bulbs, 2 x Hella driving lights, 2 130w high beams, massive Alpine amp & a CB all at the same time at road speed and I still can't get my volt gauge which runs off the ignition acc wire to drop below 13v!! At idle, with all this and in "D" it only drops to about 11.8v on the gauge but still reads at least 13.2v at the batteries!!

Cheers

Andrew

1 ) What is the voltage at the cranking battery’s terminals. 12.6

2 ) Type of vehicle. Rangie Classic, 3.9 Disco motor

3 ) What make and type of battery ( a model number will do ) Dekka Intimidator

4 ) When was the last time the vehicle was driven. 12 hours ago

5 ) How long was the last drive 85 kms

6 ) Is this your day to day drive or a once a week vehicle. Daily

7 ) Alternator size 100 amp

8 ) Is this your tow vehicle or other. other

If you can, the following info would also be of interest.

9 ) What is the voltage at the cranking battery when you first start your vehicle ( cold start ) 14.6 volts

10 ) With the motor still running, what is the voltage at your cranking battery after a 30 minute drive.
14.2 volts


Ian

1 ) What is the voltage at the cranking battery’s terminals. 12.21 11.5

2 ) Type of vehicle. DISCO TD5

3 ) What make and type of battery ( a model number will do ) EXIDE ENDURANCE 950CCA

4 ) When was the last time the vehicle was driven. 12Hr ago

5 ) How long was the last drive 45 MIN

6 ) Is this your day to day drive or a once a week vehicle BOTH

7 ) Alternator size 120A

8 ) Is this your tow vehicle or other. YES

9 ) What is the voltage at the cranking battery when you first start your vehicle ( cold start ) 14.514.6

10 ) With the motor still running, what is the voltage at your cranking battery after a 30 minute drive. 14.2 13.9 to 14.2


The Madman numbers are in green

12 hours on form the last test

1 ) What is the voltage at the cranking battery’s terminals. 12.55v

2 ) Type of vehicle. 300tdi Defender.

3 ) What make and type of battery ( a model number will do ) 1 x RACQ 4704, 1 x AMPTECH D87L, 1 x Exide ED6. No smart system, marine isolator thats never used. Age have no idea between 12-24 months

4 ) When was the last time the vehicle was driven. 12hr prior

5 ) How long was the last drive. 8km

6 ) Is this your day to day drive or a once a week vehicle.. everyday

7 ) Alternator size 100a

8 ) Is this your tow vehicle or other. My everything vehicle.

If you can, the following info would also be of interest.

9 ) What is the voltage at the cranking battery when you first start your vehicle ( cold start ) 13.8v after 10 sec but still climbing slowly

10 ) With the motor still running, what is the voltage at your cranking battery after a 30 minute drive. 13.83v 23km drive 35min running time

1 ) What is the voltage at the cranking battery’s terminals. 12.9

2 ) Type of vehicle. 300tdi Discovery

3 ) What make and type of battery ( a model number will do ) Supercharge NS70 - Age - 07/2005, so a little over 4 years

4 ) When was the last time the vehicle was driven. 12 hours ago

5 ) How long was the last drive 15 kms

6 ) Is this your day to day drive or a once a week vehicle. Daily

7 ) Alternator size 80 amp

8 ) Is this your tow vehicle or other. both - tow and general daily use

If you can, the following info would also be of interest.

9 ) What is the voltage at the cranking battery when you first start your vehicle ( cold start ) 14.4 volts

10 ) With the motor still running, what is the voltage at your cranking battery after a 30 minute drive.
14.3

Seano