Battery Discharging

[Tuppence3]

I had a new Battery in August 2020.  Around the middle of last year the car was difficult to start and I figured it was the Battery, charged it, started ok.  I had asked on here before about Battery problems (user name Tuppence, living in France).  One of you told me to buy a CTEK gadget to fit on Battery with lights to show condition.  Bought that but have only recently had it fitted to another new Battery.  I had the car serviced this February and got the man to put the gadget on.  After a couple of days I thought I'd look at it, flashing orange, later red.  Put car on charge.  Contacted garage and arranged to go over, he tested Battery and said it was shot basically, not holding charge.  Bought a new one and he put the gadget on that.  After couple of days had a look at it, flashing orange.  He said to go over and he'd try to see what was causing the discharge.  Got there and he said that sort of thing was difficult to find and he couldn't do anything.  Didn't think Toyota Lexus (Limoges) would be able to do anything either with a car that old.  ???????????????? Seems a bit daft.  I have been to Lexus Limoges, never want to go there again.

What can cause a Battery to discharge when vehicle not switched on etc.  No door lights or anything are showing.  Should a competent garage be able to find problem and fix it?  New Battery and I am having to have the car on charge every other day.  The only thing I can think is connected to this is that the boot became very difficult to open, the electronic key would not do it, and the button by steering wheel was difficult.  Can't remember how I did it now.  Difficult to close, kept/keeps coming open while driving unless I'm lucky.  boot open, little open door light used to stay on when parked unless I was careful and made sure boot was closed before leaving vehicle.  Told this guy about that, he did something and said I would have to open boot with manual key.  The little red open door light did not come on again when boot was open.  I have been doing this for about a year now.  He has just re-connected the little red light but did not say he'd done that, tried to pretend it has always been coming on and I'm mixed up.  Is there anything in the background to do with boot opening than can be running the Battery down?  Sorry for long post and if it is confused sounding.  Thanks in advance.

[Herbie]

32 minutes ago, Tuppence3 said:

One of you told me to buy a CTEK gadget to fit on battery with lights to show condition.

 

32 minutes ago, Tuppence3 said:

After a couple of days I thought I'd look at it, flashing orange, later red.  Put car on charge.  Contacted garage and arranged to go over, he tested battery and said it was shot basically, not holding charge.  Bought a new one and he put the gadget on that.  After couple of days had a look at it, flashing orange. 

I haven't got any CTEK equipment but the language you're using is not instilling me with confidence that you've got the right thing.

What it sounds like you've got is just the comfort connector that shows the state of charge, whereas what you should have is a trickle charger. This would be permanently plugged into the mains and connected to the car when it's parked up and it does what it says on the tin, ie, it constantly trickles a charge into the Battery at a low rate, thereby making sure that the Battery doesn't go flat.

Can you confirm what the exact model number of the CTEK unit is, so that we know we're talking about the same thing?

Having said that, it does sound like you have a problem with the car and the first thing I'll say is to forget about going to a general mechanics garage. It's an electrical problem so find a suitably qualified auto-electrician. It is a trade/skill in its own right and you'd never think of getting a plasterer in to sort out a plumbing problem would you?

All cars have a certain amount of current draw from the Battery, even at three in the morning while you're fast asleep. This is called a 'quiescent' current draw and general rule of thumb says that around 50 to 70mA (0.05 to 0.07A) is considered to be normal, so if it's higher then it's likely that there's a problem, which is what's called a 'parasitic' current draw.

Quiescent current is drawn to keep things alive, such as the alarm, the clock, the radio presets and the seat memory, even when the car is asleep, so that these things don't need to be reset every time you start the car.

One thing that your mechanic is correct about is that it can be very time-consuming and therefore expensive, to find the cause of a parasitic drain and to fix the problem. This is because fuses rarely control just one item, so first of all you need to know which fuse is affected, and then see what it feeds. For instance, it could be Fuse 'A' and it may control the Radio, the Dome lights, and the door lights so, once you're sure you've got the correct fuse, you then need to check the wiring out to all three circuits to find which one is actually at fault.

[Linas.P]

As above...

I would as well add that - how quickly the Battery dies and how often do you drive the car? Because if it is parked for extended periods of time (over a month) then any Battery will die. So I would say if your Battery dies a week after driving for at least 30 minutes, then there is an issue and you need to check what is causing parasitic draw, but if you Battery shows orange after 4 weeks and red after 6 weeks, then it would be in line with natural discharge. 

Following further on the same thread and as said above, you would need trickle charger to maintain the charge on the Battery in such case.

Not sure I am following on the boot opening, but if the switch is broken for the boot light and it stays ON after the boot is closed, then yes indeed the light would kill you Battery over time. However, I cannot see relation with difficulty to close the boot sounds like maybe hinge or lock problem. 

 

[Tuppence3]

To Herbs

It is a CTEK MXS 5.0 12v/5A.  The "gadget" as I called it is a CTEK 40-133 Start/stop CT5 Indicator eyelet M8  

Everything else you've said is very useful and I thank you for that.

To LINUS P

The car is used normally and may do at least 10 miles a few times a week with jnys of an hour or so every so often, certainly a few times a month.  Not used for 2 days at most sometimes.  The CTEK charge that I have then, I should programme to no. 8 which says "pulse" maintenance charging?  I usually just put it on charge and leave it till it gets to 7 = "float" Fully charged.

Again, thank you for your ans.  Appreciated.

[Linas.P]

No - if car is used most of the days and never left for over a week Battery does not need any maintenance. 

Two options really:

1. either you charging system is not working, so Battery never gets charged.
2. or there is something draining your Battery when parked.