Battery drain - what is causing it?

[OGrid]

I have no issue with battery drain. When I was camping for three nights recently, opening and shutting the vehicle doors over that time and not driving anywhere, my primary battery only dropped from 96% to 93%. I have the factory secondary battery, though no monitoring (yet).

For those without a faulty battery and an unknown battery drain source, I’m wondering if the vehicle’s alarm has anything to do with this situation. I only have the standard alarm that came with the vehicle and didn’t option up the alarm.

 

[Skydance]

I have no issue with battery drain. When I was camping for three nights recently, opening and shutting the vehicle doors over that time and not driving anywhere, my primary battery only dropped from 96% to 93%. I have the factory secondary battery, though no monitoring (yet).

For those without a faulty battery and an unknown battery drain source, I’m wondering if the vehicle’s alarm has anything to do with this situation. I only have the standard alarm that came with the vehicle and didn’t option up the alarm.

We only have the standard alarm here in the UK, although I do have a Scorpion tracker fitted by my dealer.

 

[Orcmurd]

Dual battery setup and even after being on a Ctek charger when charger shows battery full, Grenadier show SOC of 81% max. Battery discharges 3-4% each day if not driven. Dealer has tested both batteries and said they were fine. Not sure if Grenadier SOC data is accurate as she at 81%, charge rate is 1A but when SOC shows 55%, charge rate sits at 14-18A until SOC increases and then reduces.

 

[Skydance]

Dual battery setup and even after being on a Ctek charger when charger shows battery full, Grenadier show SOC of 81% max. Battery discharges 3-4% each day if not driven. Dealer has tested both batteries and said they were fine. Not sure if Grenadier SOC data is accurate as she at 81%, charge rate is 1A but when SOC shows 55%, charge rate sits at 14-18A until SOC increases and then reduces.

Mines exactly like this.

 

[Arlette]

Personally I would not be too concerned about 84% when opening the car, sitting in it with (I guess) the contact on to check the battery status. While you do that you drain quite a bit of current, and the voltage drops.
I checked it some moment ago in my car, but I have also the auxiliary battery.
The car didn't move the last 4 days and the voltage dropped from 12.81 volts to 12.68 volts while I only opened the car like 3 times, see the voltage drops on the graph.
View attachment 7853656

Today, before opening any door and doing the check IN the car I checked with my Chinese voltage monitoring spies. Main battery says 12.68 Volts and SOC (State if Charge) 87%. Beware, I don't know if the SOC calculation of the Chinese monitor uses the same algorithm as my Grenadier.
Funny thing is that my Auxiliary battery states 95% SOC with the same voltage, probably because the Voltage measurement was done at a moment the Smartpass was draining the current for recharging the Main battery!
View attachment 7853658

As soon as I open the door and put my contact on, I get a significant but normal voltage drop, and SOC of 84%:
View attachment 7853659
Confirmed by my car, SOC 83%:
View attachment 7853661

The pulses seen on my battery spy is the CTEK Smartpass recharging the Main battery from the Auxiliary, pulses of about 8A.

Therefore, again, a SOC of 84% doesn't seem to be an issue if you are using your car computer.

Jean - many thanks for your comments. Today after 4 days without use but checking the SOC daily the SOC has fallen to 62% and voltage 12.4v. I drove for 30 minutes at a good pace and raised the SOC to 64% with a typical amperage of 6amps.

 

[Tazzieman]

After watching the Thunderbirds movie (1966) last night I think Brains has cracked the problem.
I saved this:

View: https://youtu.be/XRahih-Os6Q?si=aZ0Qbk4XKT6dVgSU

 

[acwiltshire]

Mines exactly the same as yours. Single battery, 12 month old, diesel and stop start doesn’t work (never worked). I’m interested to know too. It’s either the battery is knackered or software controlling the smart battery charger because I remember one time when I got in, it said 10% battery charge. Next day 84% without me doing anything. Never been above 90%. I’ve had the software update too (1946). Last time my dealer looked at it said it was normal. Occasionally I get Ecall low battery. That’s the emergency call button in the overhead console which I believe has a separate inbuilt battery pack which charges itself when the car is running.

My diesel, single battery will be a year old next month and was showing all the above battery issues as discussed. Plunging to 40% or lower after a few days and not recovering even after a 170 mile trip. Agent had investigated and thought alternator terminal damage was cause but no. Anyhow , due to major water ingress in drivers footwell and it being held at the agent since last Dec, I have rejected and a new one is being made for me.

 

[Logsplitter]

My diesel, single battery will be a year old next month and was showing all the above battery issues as discussed. Plunging to 40% or lower after a few days and not recovering even after a 170 mile trip. Agent had investigated and thought alternator terminal damage was cause but no. Anyhow , due to major water ingress in drivers footwell and it being held at the agent since last Dec, I have rejected and a new one is being made for me.

When you get your replacement Grenadier and I get mine back from South Africa we could meet up again in your local

 

[ECrider]

My diesel, single battery will be a year old next month and was showing all the above battery issues as discussed. Plunging to 40% or lower after a few days and not recovering even after a 170 mile trip. Agent had investigated and thought alternator terminal damage was cause but no. Anyhow , due to major water ingress in drivers footwell and it being held at the agent since last Dec, I have rejected and a new one is being made for me.

What a pain. Are you changing anything from your original spec? Or are you even allowed to make changes??

 

[acwiltshire]

What a pain. Are you changing anything from your original spec? Or are you even allowed to make changes??

I was asked if there was anything I wished to re-spec. but actually no. They didnt have a stock repacement so a new build is showing on my portal.

 

[acwiltshire]

When you get your replacement Grenadier and I get mine back from South Africa we could meet up again in your local

Absolutely . park yours next to mine and show what true adventure does.

 

[Skydance]

My diesel, single battery will be a year old next month and was showing all the above battery issues as discussed. Plunging to 40% or lower after a few days and not recovering even after a 170 mile trip. Agent had investigated and thought alternator terminal damage was cause but no. Anyhow , due to major water ingress in drivers footwell and it being held at the agent since last Dec, I have rejected and a new one is being made for me.

Do you have the email to reject. I may consider this option. Thanks

 

[MileHigh]

I had battery drain down to about 40% over 5 days. I did see that I had left to of the overhead switches on, they were lit. Is this enough to drain the battery that much, with anything on those circuits?

 

[Tom109]

I will regularly park for 5 days and have not really seen any drain. I sit around 95% SOC, lowest 92%, highest 97%.

 

[TD5-90]

I had battery drain down to about 40% over 5 days. I did see that I had left to of the overhead switches on, they were lit. Is this enough to drain the battery that much, with anything on those circuits?

Absolutely.
AFAIK, the switches don't switch load current directly, but operate small relays. These small relays typically have coil currents of ~150mA. So having 2 of them turned on means a constant current draw of ~0.3A. Over 5 days of 24 hours each this results in 0.3A x 5 x 24 hours = 36Ah lost.

 

[MileHigh]

Thanks, that makes sense. I often leave it for weeks at a time for when I’m traveling for work, and it never happened before.

I’ve gotta stop playing airplane when I drop the car off for the week

 

[landmannnn]

My theory is that with the infotainment firing up every time the doors are opened is that the battery was drained at least once prior to us buying the vehicle.

So the battery will have some sulfation. Symptoms are normally slow to charge, won't fully charge and higher levels of self discharge.

The average battery tester is not able to detect low levels of sulfation.

Many car battery chargers have a conditioning function, worth giving that a shot. (Suggest a decent quality one such as Noco rather than a no name brand)

 

[TD5-90]

My theory is that with the infotainment firing up every time the doors are opened is that the battery was drained at least once prior to us buying the vehicle.

So the battery will have some sulfation. Symptoms are normally slow to charge, won't fully charge and higher levels of self discharge.

The average battery tester is not able to detect low levels of sulfation.

Many car battery chargers have a conditioning function, worth giving that a shot. (Suggest a decent quality one such as Noco rather than a no name brand)

Deeply discharged at least once before we got hold of the vehicle: This is also what I think.

Mine is regularly (at least once a week, from the date I picked it up) hooked up at my Victron charger, for several hours, and in regen mode from time to time. Result: I frequently have 100% SoC, and less idle drain than in the beginning.
It seems the batteries _really_ have regenerated.

 

[bemax]

When both batteries stood totally drained after 5 days without using the car I installed those small bluetooth readable "guards".
Since then (three weeks now) I had only one night with a unusual drain. I will now start to make some tests over night like not locking the car or leave a overhead switch on.
I am curious whether it has been my fault indeed, because I just did`t locked the car without remembering it...