Battery drain

[Steve750]

Hi, i have an 08 1.0 aygo that’s been draining the Battery for years. It’s been in the family and they took it to an auto spark way back who said he couldn’t fix it and fitted a larger Battery.

It pulls 0.08-0.11 with a clamp meter on the Battery terminal. 

has anyone experienced this and have any tips to fix it? It’s driving me mad. During the summer the battery would only go flat if left for a couple of weeks. Winter time it only lasts about a day or to but was manageable since it was always being used. Now though, as in last week it’s down to minutes lol. I’m thinking my battery may be toast but the drain will still be there 

[Mooly]

80 to 110 milliamps is high-ish for a background current drain but a new healthy and fully charged Battery (if we assume 60Ah capacity) would be be good for a couple of weeks and still start the car but that does not mean that 110 milliamp drain is OK because it would result in a slow but steady deterioration of the Battery over weeks and months.

A car with lots of use would possibly be OK under those conditions but a car used infrequently would not.

It should be easy (I would have thought) to at least isolate what area of the car is draining the Battery. Just pulling fuses until the drain disappeared would be one way.

Has the car got anything at all installed or fitted that is non standard such as a different radio or a sat nav... anything...  because those would be the first suspects.

One possible (but I think less likely) cause could be the alternator if it had a leaky diode pack. 

If its only lasting a day or so now then either the battery is totally shot and/or the drain is higher than the clamp meter reading showed.

 

 

 

[Bper]

Hi Stephen,That drain of 0.08-0.11 amps is definitely on the high side for an Aygo, so it’s no surprise that just putting in a bigger Battery didn’t fix it. First off, it might be worth checking if the Battery itself is on its last legs it sounds like it could be, with how fast it’s losing charge. You could test it with a multimeter or have a shop check it out, just to see if it’s even holding a charge anymore. If it’s shot, changing it out might at least give you a fresh start.Since you’ve got a clamp meter, one thing to try is a parasitic draw test. With everything off, go through each fuse one by one and see if you can spot the one pulling power. In older Aygos, the usual suspects are often aftermarket stereos, interior lights, or the alarm stuff like that.

You might also want to take a quick look at the wiring around the Battery and fuse box. Sometimes a bit of corrosion or a loose connector in these older cars can cause trouble. And just to rule it out, you could check the alternator too. Now and then, they can end up draining power even when the car’s off.👍

[Vandals01]

Personally, 0.08-0.11 is well within my acceptable limit.

I once drove a 2005 Renault Clio that draws 0.2-0.3Amp and had that car for 5 years.

Girl Friend had a 2008 Nissan Micra and that beast drain 0.4Amp.  It is the immobilizer so just had to live with it (don't want to pay Nissan £1000+ for a 15/16 year old car).

Drive the car at least once every 3 days and will never ran into flat Battery situations.

 

Anyway, you can try to chase that "Parasitic Draw", and I'm willing to bet it is the "Head Unit".  (Pull the fuse for the radio hidden behind the steering wheel cowl and see if the current draw drops.)

Or you can get some kind of solar charger for car Battery and hook it up while the car sat for weeks.

 

In all honesty, if you allow a car to sat for a few weeks, you might not need that car after all...

[Mooly]

One further thought I had on on all this is whether the clamp meter was both used correctly and also whether it is a type suitable for low current measurement. That last point is extremely important.

These things work by magnetic fields generated by the current flow in the cable and the potential for very large error is real at such low current. 

What I'm saying is that you may not actually have a real fault at all. I think given what you say about the Battery going flat in hours etc... get a new Battery first and see how you get on.

 

[Steve750]

Hi guys thanks for all of the replies, very helpful

11 hours ago, Vandals01 said:

In all honesty, if you allow a car to sat for a few weeks, you might not need that car after all...

I agree but its days not weeks. I bought a new car so I am trying to get to the bottom of this and a few other problems before I sell the aygo

Without quoting everyone, it seems the main points are 

• Replace Battery with the correct size. Currently has an oversized one 
• Check clamp meter is the correct type
• Re check drain
• Pull fuses and see if drain stops if it's still a problem at this stage

Thanks!

[Vandals01]

35 minutes ago, Steve750 said:

Hi guys thanks for all of the replies, very helpful

I agree but its days not weeks. I bought a new car so I am trying to get to the bottom of this and a few other problems before I sell the aygo

Without quoting everyone, it seems the main points are 

• Replace battery with the correct size. Currently has an oversized one 
• Check clamp meter is the correct type
• Re check drain
• Pull fuses and see if drain stops if it's still a problem at this stage

Thanks!

1. It doesn't matter if the Battery is oversized.  In fact, it is recommended to fit a bigger Battery so it provides more power allowance enable you to start the car. My 2012 Aygo comes with a Toyota 063 Battery when I bought it (proper size should be the smaller 079). Even though my battery tester condemn the battery as bad, it still starts the car every time thanks to the extra capacity.

 

2. The battery itself can be a problem too.  Once a battery is dis-charged, it is very hard to charge it back-up - you need a lot of juice to reverse the Sulfation effect.   More often or not, you'll need a special charger "Pulse Repair charger".  To make sure it is not the battery's problem, use a battery tester on it.  And if the battery is fairly new, you might be able to revive it using a pulse charger.  (I've repaired a battery that was condemned as dead by a battery tester.  That was 6 hours on the pulse charger then 24 hours charge on an A/C car battery charger at 5Amp per hour.  However, not every battery can be saved.)

 

Seriously, 0.08 to 0.11 is really nothing.  Given Aygo's battery ranges from 45Ah to 60Ah.  In the worst case scenario, 45 divided by 0.11 is 409 Hours.  Obviously, you can't start the car after 409 hours (17 days), but lets say half, 8 days windows to let you drive the car to recharge its battery!  So you shouldn't ran into starting problems with such a minor current draw.

[APS]

8 minutes ago, Steve750 said:

Without quoting everyone, it seems the main points are 

• Replace battery with the correct size. Currently has an oversized one 
• Check clamp meter is the correct type
• Re check drain
• Pull fuses and see if drain stops if it's still a problem at this stage

Key point is the last one - pull fuses to narrow down the culprit of the drain.

Battery size is not critical. As long as it's healthy and maintains >12.7 V for some time after being disconnected. Personally, I'd use an inline Ampere meter (multimeter) to measure the current. That gives the most accurate reading. But you have to keep your wits about and be careful not switch on anything significant. [pertinent safety disclaimer here]

 

[Mooly]

1 hour ago, Vandals01 said:

Seriously, 0.08 to 0.11 is really nothing.  Given Aygo's battery ranges from 45Ah to 60Ah.  In the worst case scenario, 45 divided by 0.11 is 409 Hours.  Obviously, you can't start the car after 409 hours (17 days), but lets say half, 8 days windows to let you drive the car to recharge its battery! 

In practice the problem is the recharging bit. This I believe is the issue with all the hybrid 12 volt issues. Lead acid batteries like to be kept in a high state of charge to limit deterioration.

What happens is the 100% good and 100% charged Battery falls to say 90% charge over a few days. No issue there but to bring it back to 100% takes longer than you think. It might hit 98% in a few minutes but if then park up again you are now starting a discharge from 98%. Say it goes 88% this time. Same happens again and now it might only be 96 or 97% charged. Over weeks and months the Battery dies.

Also as the Battery deteriorates (even just with natural aging) the recharge time lengthens because the internal resistance of the battery rises and that limits the current that can flow from the alternator (or DC/DC convertor in the case of the hybrid).

So its not a linear process to battery failure, it accelerates more and more as time passes.  

 

2 hours ago, APS said:

Personally, I'd use an inline Ampere meter (multimeter) to measure the current. That gives the most accurate reading. But you have to keep your wits about and be careful not switch on anything significant. [pertinent safety disclaimer here]

Very true. If I had to do this myself I would look at connecting the meter (well holding the probes on the terminal and post) while the main terminal was still on its post and with the car locked and in its lowest power state. You could then ease the terminal off the post leaving the meter in line.

Its not something I would probably recommend unless you are experienced in holding meter leads with hand etc. Maybe get a helper.

Some cars (thinking of my Auris) seem to go to a lower state of current draw after say ten minutes. I hear a relay click after about ten minutes from memory.  

[Steve750]

Thanks for the above 

This is my set up. Im not that confident with multimeters or electrics of any kind haha.

I noticed that the current drops to 0.06 now and fluctuates up to 0.11 but mostly holds 0.06-0.08 after 10 mins. I sanded the earth straps and re attached them, not sure if that made the difference.

I pulled all the fuses around the steering wheel and the ones beside the Battery in the engine bay one at a time. Disconnected the radio and all the big cables going into the fuse box in the engine bay. No change to the drain, I should note that the large square fuses in the fuse box wouldn’t budge so I left them. 

I need to disconnect the alternator next to see if it makes a difference just thought that’d be easier done on the lift so I left it until it’s free.

I charged the Battery today, it’s reading 12.55v after the fuse pulling so I’ll check it in the morning to see if it’s toast.

[Mooly]

I'm really not sure how accurate a clamp meter is going to be with an irregular rectangular shaped conductor like that. They should be used with normal circular conductors centrally in the jaws.

1 hour ago, Steve750 said:

I charged the battery today, it’s reading 12.55v after the fuse pulling so I’ll check it in the morning to see if it’s toast.

One unscientific test you can try if you believe it to be fully charged is to turn your headlights and heated window on (engine OFF) and monitor the Battery voltage. That would be around a 25 amp load and a new good fully charged should hold up above lets say 11.2 volts for an hour or more at that loading.  

If the voltage heads south in minutes the Battery is either duff or not fully charged.

I've done that on my Auris in the past but also had front and rear fog lights on and also operated the 4 windows up and down half a dozen times. When the Battery was down on capacity (at 11 yrs old) it would only hold up under that loading for a few minutes and then fell dramatically toward 11v and below. 

That is a super severe test and after doing that for several minutes when I went to start it (and it turned over just as smartly as normal) it promptly stalled. The reason was the massive loading on the alternator as it initially charged the battery (which makes the alternator very hard to physically turn). The idle speed needed a few seconds of feathering the accelerator to readjust and idle correctly.

 

   

[Vandals01]

3 hours ago, Steve750 said:

Thanks for the above 

This is my set up. Im not that confident with multimeters or electrics of any kind haha.

Almost identical to the Clamp meter that I had.  Mine is UT210E while yours is UT210D.  The one I had was fairly accurate (verified with another multimeter that was connected in series), you just have to zero it out before use.

As for the Battery, ideally you should have a Battery tester.  Even a cheap Chines-ium one from AliExpress (£10 -  14 before VAT).  Anyway, see what is the voltage reading tomorrow.

Another way (not very accurate but better than nothing) is to record how low did the voltage drop during crank.  To do this, you'll need a multimeter that has Max/Min function (record the voltage minimum value across the battery).  If the voltage was below 10.6v, that means the Battery is either under-charge or toasted.

[Steve750]

Thanks for the replies. I done a quick test on my Battery. Put all the lights on and the voltage fell dramatically so, got a new one yesterday and have been monitoring it.

seems fine so far. Reading 0.04 amps using my same test method on the negative terminal. What’s weird tho is the tiny earth that is bolted to the strut is reading like 0.2 amps which I want to ignore haha. Just seems strange that it isn’t different to the terminal reading 

Also replaced the rear light seals and it’s fixed an annoying water leak I had. And fixed the central locking.

Just need new front tyres and an mot then it’s ready for a new owner!

[Steve750]

Double post 

[Mooly]

11 minutes ago, Steve750 said:

Thanks for the replies. I done a quick test on my battery. Put all the lights on and the voltage fell dramatically so, got a new one yesterday and have been monitoring it.

I wish more would do tests like that. They are so revealing.

It would also be an interesting one to do on a new car on delivery day while still at the dealers... that could start a panic.

I can't diagnose the 0.04A vs 2A conundrum without seeing clearly what and how things are being measured. Never easy at a distance 🙂

Another test that can be done is having discharged the Battery a little (lights on for a couple of minutes) is to look at the charge current when in Ready Mode and so on. A healthy Battery should draw 10's of amps for a brief period before levelling off. I have no idea what the DC/DC convertor can deliver in a Hybrid though. An alternator would be up in the 70A+ region though if heavily loaded.