Technical 2004 1.2 Dynamic losing charge on a new battery (No Parasyitic Drain?)

[ScottEnock]

Hi guys,

All through the winter my Panda has been losing its charge through the night and is unable to start in the mornings. The battery is a year old and has been checked by QuickFit which gave it an all clear.

When the engine is on the battery is recieving 14 volts and always starts up after a drive, so the alternator isn't the cause.

I checked the amp draw to check for any parasytic drains and get a reading of 0 when the car is off which really threw me.


I was told it could possibly be a bad earth, and cleaning them might solve the issue. In particular I was told to check the earth that leads from the gearbox to the engine. I'm relatively new to working on cars and was unable to find that particular earth.

If anyone has any advice I'd really appreciate it. Thanks.

 

[koalar]

where to start.


First. Its not an earth problem causing a leak over night.


second a good working car to have a small drain. Can't be 0. ECU memory. clock, remote receiver all have a draw. If you lock the car while measuring the drain you will see it drop after about 30 seconds as unnecessary circuits are put to sleep. (can't remember exactly. The active and were dynamic are slightly different. From memory after 30 sec it drop to 200mA


Third both my Pandas measure over 14V one is 14.1V and is marginal the other is 14.2V


I suggest you measure the parasitic drain again? There something wrong here.


Or disconnect the battery overnight and retest the following morning. At least you would know for sure if its really a drain.

 

[Wee Smurf]

Is it with the original radio. Some have been known to come on in the night and drain the battery. Mine has been known to have a wee disco in the garage on occasion.

 

[koalar]

the earth on top of the gearbox can cause a problem with the starter motor not turning or turning slowly. The rest of the electrics will work fine

its easy to test for this. Take a jump lead from the plate on top of the gearbox to the battery negative terminal and are try

 

[DaveMcT]

How did you test for parasitic drain?

The only reliable way is with an ammeter between battery post and earth lead. Leave it connected and keep checking over a few hours to see what develops.

Having had a questionable alternator, I would check that's not developing a back feed through the reg/rectifier. A fault there can also fry a (previously) good battery with over voltage.

 

[GeorgeDamper]

Is it with the original radio. Some have been known to come on in the night and drain the battery. Mine has been known to have a wee disco in the garage on occasion.

I had this problem on my 53 Reg Panda Dynamic. I found the answer in the Punto section. Keep a CD in the CD slot. There is a microswitch that can develop a fault. If there is no CD it triggers the radio.

 

[ScottEnock]

Sorry, I should have been more specific with my measurements, It was quite a while since I checked with my multimeter and writing the post. The 14 V when engine is on was slightly higher.


I just checked the current draw multiple times, sometimes it would go all the way down to 0.00 mA and occasionally fluctuate to 0.01 mA. Which I think is what threw me, it definitely seems like a parasyitic drain because it starts fine when I disconnect the negative terminal over night.


The other values I got which I think are likely to be the more accurate and correct ones were when first connecting the battery with the multimeter it would read 0.23 mA and raise to 0.30 ish mA and then would make its way down to 0.04 - 0.05 mA. Is that a normal draw? ( My battery is dead around 11 volts when I took these readings)

 

[koalar]

Sorry, I should have been more specific with my measurements, It was quite a while since I checked with my multimeter and writing the post. The 14 V when engine is on was slightly higher.


I just checked the current draw multiple times, sometimes it would go all the way down to 0.00 mA and occasionally fluctuate to 0.01 mA. Which I think is what threw me, it definitely seems like a parasyitic drain because it starts fine when I disconnect the negative terminal over night.


The other values I got which I think are likely to be the more accurate and correct ones were when first connecting the battery with the multimeter it would read 0.23 mA and raise to 0.30 ish mA and then would make its way down to 0.04 - 0.05 mA. Is that a normal draw? ( My battery is dead around 11 volts when I took these readings)

with the doors locked. When you first connect it measures 800mA then drops to 39mA. Are you sure your not on amps range as .04 amps would be 40mA

 

[ScottEnock]

My bad. I believe I was using the 10A socket when using the mA setting. I went out and rechecked it. Using the 10A setting it first reads 0.46 A and then drops to 0.05 A.

 

[koalar]

50 mA is fine mines 39 mA. Variations in accuracy in our meters and battery volts.

Try measuring the voltage while raising the revs.

 

[varesecrazy]

My bad. I believe I was using the 10A socket when using the mA setting. I went out and rechecked it. Using the 10A setting it first reads 0.46 A and then drops to 0.05 A.

In your position.. I would spend £8 on a battery isolator..

And have the option of actually using the car

Get time to progressively fault find.. without having flat batteries in the morning.

 

[DaveMcT]

Mine has a quick release clip on the earth post.


When you have found the fault, an isolator with a 10 Amp fuse across makes a great anti theft device as fuse will blow if the starter is used.

But for that you would need to run heavy cables into the cabin and hide the switch in an easy to use place.

 

[Pugglt Auld Jock]

My bad. I believe I was using the 10A socket when using the mA setting. I went out and rechecked it. Using the 10A setting it first reads 0.46 A and then drops to 0.05 A.

Hmm. Very puzzling. There is a fault which can give this symptom. It comes about if the battery suffers an internal short. (on older batteries often caused by plate dust accumulating in the bottom of the cells and shorting out the plates causing a slow discharge. On newer ones it's maybe due to poor manufacture - very cheap battery). But in your case I don't think it's this as the battery holds it's charge if you disconnect it. Alternator diodes can also get pretty cheeky too. It just takes one diode in the pack to partially fail and it will "leak" slowly to earth when the engine is stationary. At the same time though, You may well find it can still charge the battery well enough to work the starter! Temperature can affect this so you need to be checking for leakage with it hot and cold (and in between if possible).

I don't have a current clamp so I would be testing for this with the earth lead disconnected and a multimeter bridging between the battery post and the disconnected earth cable terminal. Of course, in Amps mode, by the very nature of the measurement, the multimeter has no internal resistance (although high quality devices may feature protection) so if you try passing a high current (for instance trying to operate the starter) you're probably going to "fry" the meter so be careful. The sort of milliamp readings (1000 milliamps = 1 amp) quoted above, after the whole car has been shut down, are reasonable to expect. Talking about earth leads, the lead you first mentioned and then later mentioned by koalar runs gearbox casing to N/S chassis leg - not gearbox to engine. The one on my 2010 is badly corroded and I really should change it. Mine is of the open design (no external insulation) so I can see how corroded it is easily. If you have the type which has external plastic insulation I believe I've seen reports on our forum of them suffering badly from internal corrosion which, of course, you can't see. Again though it doesn't sound like this is your present problem, which is not to say your cable might need changing soon for this reason.

I think I would be setting up the multimeter in this way and then monitoring it for several hours at least from full running temp to full cold. If you suddenly see a current draw then you can start merrily pulling fuses, one at a time, till you isolate the offending circuit and then have lots of fun trying to find the offender itself!

Hope you have fun. Sometimes these sorts of things can be very frustrating to find and fix.
I often find talking to "the old girl" and thinking about how much it would have cost to hand her over to "an expert" keeps me sane?
regards
Jock

 

[DaveMcT]

Normally the simple way to check the alternator for leak current is to disconnect it and see if the charge holds and/or the current draw goes away. Unfortunately Fiat put the alternator under the back of the engine in a place that's only accessible from under the car. Even then its awkward, but I do suspect this is a likely culprit so worth considering.

Old batteries commonly fail due to internal shorts. For example, you park at home on level ground and never have a problem. You go somewhere and park on a hill to find the battery is stone cold dead flat. The cause is sludge in the cells bunching up and shorting out. Such a battery will quickly go from flat to fully charged as its total capacity is low.

A new battery can have a faulty cell but that won't do the "all gone flat" thing. The worst you can expect is one cell going down or failing to take a charge. That will give a slow starter and refusal to fire up or random starting/not starting.

As Jock says, a strange current drain on the car has to be investigated circuit by circuit.

 

[varesecrazy]

Mine has a quick release clip on the earth post.


When you have found the fault, an isolator with a 10 Amp fuse across makes a great anti theft device as fuse will blow if the starter is used.

But for that you would need to run heavy cables into the cabin and hide the switch in an easy to use place.

You are referring to a motorsport style.

I meant the 2 pieces of Brass items that just fit on a battery post.

Completely isolate power.. so a drained battery is NOT related to a wiring issue.

In my position it would seem 10 mins well spent.

 

[DaveMcT]

You are referring to a motorsport style.

I meant the 2 pieces of Brass items that just fit on a battery post.

Completely isolate power.. so a drained battery is NOT related to a wiring issue.

In my position it would seem 10 mins well spent.

I was thinking of the motorsport style. But my Panda has a quick release (lever type) clip on the earth post. Mine is like a bicycle wheel spindle clamp but this has a similar idea.
https://www.ebay.co.uk/itm/2-x-Batt...h=item33f3b0b0a9:g:pV8AAOSwyH5bj6GR:rk:5:pf:0

 

[varesecrazy]

Yes..later cars have those cam.lock posts.... my 04 does not.

I fitted one of the brass isolators to the X1/9.. saved a lot of grief over the winter..
on dry days it was 2 minutes before it was out on the road..all tool free

 

[DaveMcT]

The red and blue plastic QD connectors that are all over eBay are a waste of money. (1) they need so much force to release you'll need a tool to lever it up and (2) the plastic covers break.

A 10mm spanner in the glove box does the job until you've found the fault.

 

[koalar]

this has got complicated.

my Panda with a similar drain lasts an easy two weeks not being driven even in winter.

The original post states the battery is flat the following morning

Something is wrong and needs fixing.


First thing to do is disconnect the battery overnight as per post 4. If it still failed which I suspect it will then the problem will be in the charging system and/or battery.


Its possible to start a car straight after a run with a fairly discharged battery which then will not start the car after the engine has cooled down.

 

[varesecrazy]

Our 04 active.. will sit happily for months.. we have a factory cd unit in it now.. still really good.

My suspicion is still with the battery


But incoupling the terminal clamps will soon render them 'tired'.

Hence the suggestion of the isolator.