Low battery - 6.5 - 8.5V

[Disco-tastic]

Hi all,

This morning the D3 wouldn't start - it at first gave a low voltage warning then would just switch off when you turned the ignition on. I plugged in the IID Tool and it showed an at rest voltage of 8.5V and when you had the ignition on a voltage of 6.5V

The battery is just under two years old (I can't find the bloody receipt! [bawl]) and shows no signs of damage. The car was last driven last Sunday, so it has sat still for less than 5 whole days. I have a Traxide SC80 installed, and when I last checked it on Sunday it was flashing to show it was over 85% charged.

I have never seen it drop this low, and I was of the understanding that the SC80 isolated the batteries when voltage dropped below a certain level, giving me some security against this happening. I have seen people isolating the SC80 when storing the car for a while - Can someone please explain why?

Also, can someone recommend a good battery charger - I have thought about getting one for a while now as Finn's battery will need to be topped up every now and then. I have anderson plugs at the back of the D3 which is my preferred charging method.

Cheers

Dan

[DiscoMick]

Cold weather can affect batteries.
If you put it on a multi-stage charger for several days the regular excitement caused by the charger should help to prevent sulphur build-up and keep it healthy. They like periods of excitement followed by rest periods.
I have two Projecta chargers, which are fine, but any of the well-known multi-stage ones should do a good job.

[DiscoMick]

BTW I have never done anything to isolate my SC80, but I have an 80 watt solar panel on the roof rack to keep the starting battery charged, so my experience may not be typical.

[Turtle60]

If you have an sc80 I’m sure Tim from traxide would be happy to discuss with you direct. Perhaps your battery has just had a catastrophic collapse. And drained that low it will probably dodgy going forward and new one needed. Just replacing mine now so feel your pain.

[l00kin4]

Switching it off is to stop it drawing power. Turning off the SC80 or using storage mode discussed in these threads:

https://www.aulro.com/afvb/l319-discovery-3-and-4-a/265313-battery-failure-2-grrr-5.html#post2849108

Traxide isolator earth wire on/off switch (https://www.aulro.com/afvb/l319-discovery-3-and-4-a/267695-traxide-isolator-earth-wire-off-switch.html)

David

[josh.huber]

Hi all,

This morning the D3 wouldn't start - it at first gave a low voltage warning then would just switch off when you turned the ignition on. I plugged in the IID Tool and it showed an at rest voltage of 8.5V and when you had the ignition on a voltage of 6.5V

The battery is just under two years old (I can't find the bloody receipt! [bawl]) and shows no signs of damage. The car was last driven last Sunday, so it has sat still for less than 5 whole days. I have a Traxide SC80 installed, and when I last checked it on Sunday it was flashing to show it was over 85% charged.

I have never seen it drop this low, and I was of the understanding that the SC80 isolated the batteries when voltage dropped below a certain level, giving me some security against this happening. I have seen people isolating the SC80 when storing the car for a while - Can someone please explain why?

Also, can someone recommend a good battery charger - I have thought about getting one for a while now as Finn's battery will need to be topped up every now and then. I have anderson plugs at the back of the D3 which is my preferred charging method.

Cheers

Dan

What brand is the battery, is it stamped on the terminals at all, is there a number or letter burnt into the top casing? If it is, you don't need a receipt, that's the date code, they will replace generally.

[LRD414]

.... I was of the understanding that the SC80 isolated the batteries when voltage dropped below a certain level, giving me some security against this happening. I have seen people isolating the SC80 when storing the car for a while - Can someone please explain why?
Dan, the isolator will separate the batteries but that won't stop a battery from dying.
The isolator can only protect your cranking battery from external problems, like excessive drains from accessories or failure of the aux battery.
As David mentioned, the disconnection of the isolator simply stops it from being an unnesscessary drain during times of inactivity.

I'd say your battery is cactus at those very low voltages.

Cheers,
Scott

[Disco-tastic]

What brand is the battery, is it stamped on the terminals at all, is there a number or letter burnt into the top casing? If it is, you don't need a receipt, that's the date code, they will replace generally.https://uploads.tapatalk-cdn.com/20190607/8574b31998337649147348cedc8962c5.jpg

Is that the sort of thing you mean?

[Disco-tastic]

Dan, the isolator will separate the batteries but that won't stop a battery from dying.
The isolator can only protect your cranking battery from external problems, like excessive drains from accessories or failure of the aux battery.
As David mentioned, the disconnection of the isolator simply stops it from being an unnesscessary drain during times of inactivity.

I'd say your battery is cactus at those very low voltages.

Cheers,
ScottYeah i fear its way past cactus. I just put a multimeter across it and measured 5.65V. The last battery i had died and it measured 10.5V so i have no idea what happened here.

I will take it back to where i bought it from and see how i go with warranty. Its a century battery so I expected longer service from it!

[drivesafe]

Hi Dan have measured the voltage on your auxiliary battery?

If your cranking battery is still in your Disco, and loosing voltage like that, I suggest you check out your alternator.

If the alternator has cooked a diode, while it will still work while the motor is running, it can flatten a cranking battery in a similar way to how yours is discharging, while the motor is off.

[scarry]

I would also isolate the batteries,disconnect the thin earth wire off the SC80,will do the trick.

If you don't,once you charge the main battery,the SC80 will close the relay,and both batteries will be connected,which is what you dont want to happen.

Then charge them separately and see how you go.

I use a C TEck,5A,seems pretty good.

[Disco-tastic]

Hi Dan have measured the voltage on your auxiliary battery?

If your cranking battery is still in your Disco, and loosing voltage like that, I suggest you check out your alternator.

If the alternator has cooked a diode, while it will still work while the motor is running, it can flatten a cranking battery in a similar way to how yours is discharging, while the motor is off.Yeah just checked and the aux measured 11.9v and managed to start the car via a jumper lead.

I hope its not the alternator :( the battery isnt at all swollen like it was last time though so you might be on the money. I will have to look up those threads about installing an isolator on the alternator.

Ive set the SC80 in storage mode and will see what the cranking battery measures in the morning. Then I might go for a drive and get it tested to confirm if its the alternator.

Cheers

Dan

[josh.huber]

No one likes buying batteries, of all the ones you can buy Century in my experience has to be the worst by far. However, usually just the blue and yellow ones. I have never really had a bad time with the black ones. Delco, super charge, exide thats what you want.

[Disco-tastic]

So the battery has worked fine all weekend, which is a good sign. I last drove the car yesterday around 4pm and the SC80 is only flashing red 3 times before going green, which means the batteries down to 60-70% (i think), so there is definitely a drain.

Can i just take the earth lead off the alternator to isolate it or do i need to unplug it as well? Can i do that in the petrol without pulling apart the fan and belts?

Cheers

Dan

[Pinelli]

There's no earth lead to an alternator. It earths through the engine. There is a 12V cable to the alternator, a big thick red one connected to the battery, and the control cables. I think the V6 is the same alternator as the V8 so a three pin plug off the back. You can disconnect the red alternator cable at the battery, and at the alternator, and I think if you then unplug the three pin control cable at the back of the alternator you will isolate it from the battery enough that it won't cause any issues. Of course, it won't charge either, but it won't be doing that if it's stuffed anyway. You could then charge the battery using a battery charger, and see if it loses voltage while sitting there. Other's with more experience may correct me on this.

In the V8, the alternator is quite easily accessible from underneath by removing a small plastic panel underneath the engine, drivers side.

[Grahame Roberts]

If you paid by Visa that is proof enough, either off your statement or app.
If you bought online or from from a Battery shop they keep records too of your purchase via the battery codes etc.
I sent one back by post from Brisbane to Sydney once and had a new one sent up overnight.
Good luck.


Hi all,

This morning the D3 wouldn't start - it at first gave a low voltage warning then would just switch off when you turned the ignition on. I plugged in the IID Tool and it showed an at rest voltage of 8.5V and when you had the ignition on a voltage of 6.5V

The battery is just under two years old (I can't find the bloody receipt! [bawl]) and shows no signs of damage. The car was last driven last Sunday, so it has sat still for less than 5 whole days. I have a Traxide SC80 installed, and when I last checked it on Sunday it was flashing to show it was over 85% charged.

I have never seen it drop this low, and I was of the understanding that the SC80 isolated the batteries when voltage dropped below a certain level, giving me some security against this happening. I have seen people isolating the SC80 when storing the car for a while - Can someone please explain why?

Also, can someone recommend a good battery charger - I have thought about getting one for a while now as Finn's battery will need to be topped up every now and then. I have anderson plugs at the back of the D3 which is my preferred charging method.

Cheers

Dan

[Disco-tastic]

If you paid by Visa that is proof enough, either off your statement or app.
If you bought online or from from a Battery shop they keep records too of your purchase via the battery codes etc.
I sent one back by post from Brisbane to Sydney once and had a new one sent up overnight.
Good luck.Thanks Grahame.

I cant even find the transaction history. Not sure why, as I know roughly when it was and i know the store.

At this stage it looks like the alternator anyways. Car is ok for a day sitting but wont last longer than that. Over the weekend i will isolate the alternator and measure voltage drop. With the alternator connected i measured a 0.3V drop (12.47 to 12.17) over an 18hr period.

[Disco-tastic]

Sooooo I snapped the retaining clip off the alternator 3pin plug. I didn't know what the red clip was for (I'd never seen one before) and accidentally snapped it, leaving the tongue inside the clip. On trying to depress the clip I snapped the end off it :mad: so now it has no mechanical retaining mechanism.

Does anyone know of another way to fix the clip on? I had a quick look to see if a zip tie would work, but I can't see any suitable holes on the alternator side.

I can get a new plug from the US for $40 but I'm not that keen to as I don't have any tools to remove and reinsert the wires...

[Disco-tastic]

Well, I left the alternator disconnected for 15hrs to see if the battery still dropped and the battery went from 12.68 to 11.9V in that time, so I'm guessing it's not the alternator. the second battery was isolated through the SC80 and was at 12.6V, so it doesn'e appear to be anything to do with the SC80.

My next step is to totally disconnect the battery overnight and measure the voltage drop.

If the battery comes up good from that, does anyone have any ideas what could be drawing the current?

Cheers,

Dan

PS. thanks for the suggestions regarding the alternator. I ended up getting a zip tie in there.

[DiscoMick]

Is the vehicle being left locked or unlocked? If it's unlocked, has it shut down or are the electronics still active, draining power? Also, wouldn't opening the door wake up the electronics which would then go through a check?

[Disco-tastic]

Is the vehicle being left locked or unlocked? If it's unlocked, has it shut down or are the electronics still active, draining power? Also, wouldn't opening the door wake up the electronics which would then go through a check?It was left unlocked overnight as i was concerned the battery would drain beyond the point of unlocking the car, though everything was shut.

Ive left it unlocked overnight before with no issues.

Cheers

Dan

[LRD414]

My next step is to totally disconnect the battery overnight and measure the voltage drop.
If the battery comes up good from that, does anyone have any ideas what could be drawing the current?
If the alternator is disconnected I still think the battery is your issue Dan.
The normal small drain from ECU checks every few hours overnight could be causing the voltage drop you're reading if the battery is cactus.
Remember the battery measured at very low voltage in your initial post.
The battery taken out of vehicle without any load on it may not show symptoms.
Perhaps a proper battery test is the go.

Cheers,
Scott

[DiscoMick]

Doesn't leaving it unlocked mean the electronics are still active and doing periodic checks, draining power?

[LRD414]

Doesn't leaving it unlocked mean the electronics are still active and doing periodic checks, draining power?
Locked or unlocked makes no difference to the periodic checks, which draw very little power anyway.
Older models take longer to go to sleep initially after stopping when left unlocked (approx 30min versus 3min).

Scott

[drivesafe]

Hi Dan, charge everything back up and then disconnect your cranking battery’s NEGATIVE ( - ) terminal and then see if the battery’s voltage drops over night again.

[Disco-tastic]

Hi Dan, charge everything back up and then disconnect your cranking battery’s NEGATIVE ( - ) terminal and then see if the battery’s voltage drops over night again.Thanks Tim. Should i disconnect the second battery before?

Can you please explain the logic so i have a better understanding of whats going on? I'm assuming you're checking foe an earth leak or something, but I dont really know.

Cheers. Dan

[trout1105]

If you fully charge the cranking battery then disconnect the earth lead overnight you will be able to tell if the battery is RS If the voltage has dropped overnight[thumbsupbig]

[Disco-tastic]

well, I unplugged the negative terminal of the main battery (and disconnected the secondary battery). I first unplugged the battery completely and it measured 12.5V. An hour later I reattached the positive terminal at it measured 12.53V. This morning it measured 12.5V again (about 12 hrs total)

Previous measurements were 0.3V and 0.7V loss over 17hrs, so i take this to mean the battery is not the cause of the problem (even if it may be damaged).

My next step will be to disconnect the SC80 overnight and measure voltage drop.

If anyone with more knowledge than me has any further opinions please let me know!

Cheers
Dan

[austastar]

Hi,
I think it is the little yellow earth wire that you need to disconnect to turn it off.
Chers