Freel2,

I am looking for comments about what is the lowest voltage during cranking that you find acceptable before replacing the battery.

The reason for my question is because the battery in my Son's Volvo with the same 3.2 as my LR2 died hard, the Land Rover is tough on batteries and I do replace mine every 4 years but when the LR2 battery fails I have always been able to recharge and start the engine. The Battery in the Volvo would not accept a charge. The capacity dropped to almost zero. It wouldn't even click the starter solenoid. (Note: I checked and all of the cells were still full of fluid)

Because my Daughter will be taking the LR2 to her University she got the new battery and the S80 got the old battery from the LR2


For reference here is the Voltage Dip at the battery when cranking
(note: my volt meter has a MIN function and that is what I used)

LR2________11.07 Volts (New battery)
A4 2.0T_____10.64 Volts MFG --> April 2019
328i________10.20 Volts Original battery from 2015
Jetta 1.8T____10.53 Volts Original battery from 2015
S80_________To be determined or possibly replace depending on the guidance I receive here

All measurements were above 77F (or 25C if that makes more sense)


For reference GM thinks "the battery voltage should remain 9.6 volts or above. (These are GM specs for a battery at 70 F; your mileage may vary.)"

https://www.popularmechanics.com/cars/how-to/a2074/4221215/

Thanks

Paul

PS The Volvo battery is a H6 and the LR2 battery is a H7. (The designation for these sizes may be different in the UK. But the important take away is that the LR2 has the Large battery that clamps correctly in the battery box and the S80 has the small battery that requires the alternate battery hold down location. The battery box is the same for the LR2 and S80)

The problem with a starter battery is that it will still start the car for a few more years. But the issue is, it has far less capacity, no worthwhile AH left. So if the car has heavy shutdown & startup sequences plus say a cold morning etc & wifey is about to have a baby...

The car is stuffed. Or more to the point you are stuffed. This happened to a neighbour.

I also replace the battery every 4 years or before we go outback. A battery amortised over 4 years doesn't cost much.

I still have the original battery for testing things & it's ok. Also lent it to a neighbour for jump starting his Honda's 47AH battery.

At the end of the day just replace the battery. Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

p_gill wrote:

Freel2,

I am looking for comments about what is the lowest voltage during cranking that you find acceptable before replacing the battery.

The reason for my question is because the battery in my Son's Volvo with the same 3.2 as my LR2 died hard, the Land Rover is tough on batteries and I do replace mine every 4 years but when the LR2 battery fails I have always been able to recharge and start the engine. The Battery in the Volvo would not accept a charge. The capacity dropped to almost zero. It wouldn't even click the starter solenoid. (Note: I checked and all of the cells were still full of fluid)

Because my Daughter will be taking the LR2 to her University she got the new battery and the S80 got the old battery from the LR2


For reference here is the Voltage Dip at the battery when cranking
(note: my volt meter has a MIN function and that is what I used)

LR2________11.07 Volts (New battery)
A4 2.0T_____10.64 Volts MFG --> April 2019
328i________10.20 Volts Original battery from 2015
Jetta 1.8T____10.53 Volts Original battery from 2015
S80_________To be determined or possibly replace depending on the guidance I receive here

All measurements were above 77F (or 25C if that makes more sense)


For reference GM thinks "the battery voltage should remain 9.6 volts or above. (These are GM specs for a battery at 70 F; your mileage may vary.)"

https://www.popularmechanics.com/cars/how-to/a2074/4221215/

Thanks

Paul

PS The Volvo battery is a H6 and the LR2 battery is a H7. (The designation for these sizes may be different in the UK. But the important take away is that the LR2 has the Large battery that clamps correctly in the battery box and the S80 has the small battery that requires the alternate battery hold down location. The battery box is the same for the LR2 and S80)

It was a dead cell in my neighbour's 2 year old Honda. Voltage was reasonably ok but the battery couldn't always turn the engine over.

He had taken the car back a few times. It was only when he turned up with an 80AH battery & welding cable jumper leads that Honda got the message. Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

Depends on so much more things...
Let's take only the cables from the battery to the starter.
If they are thinner or just longer will mean a greater electric resistance. This will mean a smaller starter current and this will mean a smaller load on the battery which in turn will mean greater voltage at the battery when cranking.

Update

I tested the Volvo with the used LR2 battery


LR2________11.07 Volts (New battery)
A4 2.0T_____10.64 Volts MFG --> April 2019
328i________10.20 Volts Original battery from 2015
Jetta 1.8T____10.53 Volts Original battery from 2015
S80_________10.52 Volts MFG --> May 2017

In the past I believe that a latched module (likely Satellite Radio or Bluetooth) was responsible for my LR2 battery dying every 4 years. I have a 4 year old LR2 battery in my S80 and the Voltage Dip doesn't seem too bad.

If I assume that Motion's minimum of 10.3 is valid then the battery is still good.


Also note that for the BMW I wasn't able to get to the battery (the trunk was full) so I measured it in the Engine compartment. Therefore the 10.2 Volts includes the Voltage dip of the battery and the Voltage drop of the wiring. But the test is reasonable because the test location is close to the starter. But still not Apples to Apples.

Maybe I need to buy a battery tester

Thanks

Paul

238amps to start my 2.0L petrol engine. So a bit more for a diesel engine.

1awg (42mm²) 1 metre has a voltage drop 0.099 volts for 238amps.
1/0awg (53mm²) 0.078v drop.
2 awg (33mm²) 0.124v drop Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

Please be careful testing batteries.
There are now several different battery designs, standard, AGM, flooded, tubular to name but a few. Vehicles have battery monitoring systems fitted which can be damaged or confused by traditional battery drop testers. Many garages now have electronic battery state measuring devices specific to the type of battery they are testing. Tangiers Orange - gone, missing her
Replaced by Ewok what a mistake - now a happy Disco Sport owner