Hi,

I have a 2016 Fiat Panda 1.2 with 26,000 miles on it. The past couple of months I’ve noticed a roughness when idling and slight ‘kangaroo’ behaviour when accelerating gently in traffic and when easing off the throttle when in slow moving traffic. The car has had a new set of spark plugs and coil pack but the issue persists. I also noticed a couple of days ago as I was driving in the dark that the headlights, tail lights, number plate lights and interior light seem to gently flicker in time with the roughness when idling.

I wondered whether the issue could lie with either the voltage regulator or the alternator perhaps, but I’m not sure this would cause the issues with the idling or the slight ‘kangaroo’ behaviour.

I have got the car booked into Fiat but the earliest they could get me in was in three weeks time so I wondered if anyone had any ideas what could be causing the issues?

Any thought would be greatly appreciated.

Hi

Is it the original battery..?

Some cars need another after 3 years..

It starting the engine ok is no longer a guarantee of 'still good'..
we had a panda die at the side of the road with a bad battery.. only electrical problem it ever suffered..


An @£80 battery would be cheaper than FIAT 'having a quick look'..

Yes it’s still on the original battery, so it’s 5 and a half years old now. Its had a test and it says it’s ok but it probably wouldn’t hurt to replace it given the age. Like you say, cheaper than Fiat taking a look and it’s worth a punt.

I have just replaced the battery on my 3 year old Panda as the power steering didn't feel right & was taking longer to start than normal. My Panda has done 30k so not much more than yours, I can highly recommend Battery Megastore where I purchased my battery from. I got a Varta Silver Dynamic battery which in Euro Car Parts would cost anywhere between £100-£200, from Battery Megastore it was £61 but with a Ebay 20% discount code it cost me just under £50 with free 24hr delivery & has solved all my issues, power steering now feels right & also starts & idles better.

Tayna ship batteries to your home address at great rates too..
How my 2012 battery is still keeping my punto happy is quite a thing

And the original factory fitted batteries are only 360 amps. Not good.

FiatMatt94 said:

I have just replaced the battery on my 3 year old Panda as the power steering didn't feel right & was taking longer to start than normal. My Panda has done 30k so not much more than yours, I can highly recommend Battery Megastore where I purchased my battery from. I got a Varta Silver Dynamic battery which in Euro Car Parts would cost anywhere between £100-£200, from Battery Megastore it was £61 but with a Ebay 20% discount code it cost me just under £50 with free 24hr delivery & has solved all my issues, power steering now feels right & also starts & idles better.

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Was that a stop start battery? Sounds very cheap if it was. (assuming your Panda has stop/start. If it has, needs an AGM battery to support the more frequent starting and to provide power while engine off... typically nearer £70 - £100 at Tanya, or over £200 at ECP!)

Herts Hillhopper said:

Was that a stop start battery? Sounds very cheap if it was. (assuming your Panda has stop/start. If it has, needs an AGM battery to support the more frequent starting and to provide power while engine off... typically nearer £70 - £100 at Tanya, or over £200 at ECP!)

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My panda didn't come with stop start as it is only a 1.2 Pop which is probably the reason it was nice & cheap . I decided to get a decent brand battery as I read on the forum about how much power the dualdrive system uses & also there is no point in buying cheap brands as a lot of them don't last long, we've had Varta batteries in the family Fiat's before switching them between different cars & they last at least 10 years sometimes longer whereas I have known people to buy Halfords or Lion batteries which were absolute junk what would either die just outside a 3 year warranty or start leaking acid, I suppose as with most things you get what you pay for .

KPat said:

And the original factory fitted batteries are only 360 amps. Not good.

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My original Mopar battery was 50ah 420 amps but still not great whereas my new Varta one is 54ah 530 amps, starts up quicker, idles better & steering feels better than before. I've also noticed the front electric windows seem to go up & down much quicker than before as they were a bit slow, everything just seems to work better since installing the new battery . I'm also tempted to fit a thicker battery earth cable & engine/gearbox earth straps as I was shocked as to how thin the wires/straps are, which is probably why they give trouble as I have read on here, not like the old 70's or 80's Fiats such as 131's, Panda's etc which had quite thick earth cables

If you look in any ‘modern’ car — the Panda is of course actually a 10 year old design — *all* the wires are very thin. Cars have become heavier out of necessity (crash tests etc), but at the same time, pressures for economic performance mean every possible bit of excess weight is sought out and removed. Making every cable ‘the optimum’ thickness to work is one result. Things like first, ‘space saver’ spares (they save more weight than space), and then removing the spare altogether are another example. The issue with the smaller gauge wiring doesn’t seem to have caused any issues (on any make of car) - so long as everything’s kept clean and tightly connected?

Herts Hillhopper said:

If you look in any ‘modern’ car — the Panda is of course actually a 10 year old design — *all* the wires are very thin. Cars have become heavier out of necessity (crash tests etc), but at the same time, pressures for economic performance mean every possible bit of excess weight is sought out and removed. Making every cable ‘the optimum’ thickness to work is one result. Things like first, ‘space saver’ spares (they save more weight than space), and then removing the spare altogether are another example. The issue with the smaller gauge wiring doesn’t seem to have caused any issues (on any make of car) - so long as everything’s kept clean and tightly connected?

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The current carrying capacity of cables are inversely proportional to their length. If the those battery cables were 1 metre long they would only be good for about 100 amps continuous flow. As they are only less than a third that length they are good for 300+ amps. More than enough for a starter motor. This is why those cheap long and thin jump starter cables are so useless.

KPat said:

The current carrying capacity of cables are inversely proportional to their length. If the those battery cables were 1 metre long they would only be good for about 100 amps continuous flow. As they are only less than a third that length they are good for 300+ amps. More than enough for a starter motor. This is why those cheap long and thin jump starter cables are so useless.

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I agree with the gist of what you are saying, but your reasoning is not strictly true (for any physics students reading this). No offence intended.

The dc current carrying capacity is proportional to cross-sectional area, and not related to cable length, but the cable resistance increases with cable length.
{Resistance = resistivity x length / cross-sectional area}.
This means that the long thin cables have a higher resistance and this does reduce the current through the starter motor from a fixed voltage source, compared to using a shorter or fatter cable.
The cable could still carry the higher current if the source voltage was increased to compensate for a longer cable. The cable dissipates the extra power as heat.

Before this gets too technical, I actually missed making the point I’d intended to make: the earth connection to the engine block can be as big as you like, but only needs to match that of the positive to the starter.

Herts Hillhopper said:

Before this gets too technical...

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Don't stop them! Some of us are learning stuff here!

One of the favourite things that can happen with resistive loss on thin and long cables is the drop on headlamps. One of the reasons the Panda has poor headlamps is the loss. If you measure the voltage across the bulb its above one volt of a loss I think 1.4v on the older Lounge. The loss is in both the earth lead up to the headlamp and the feed to the bulb from the fuse box. This is actually a significant loss.

I'm not so sure about saving weight, more like saving on production costs, copper wire is not cheap these days.

chr1s said:

I agree with the gist of what you are saying, but your reasoning is not strictly true (for any physics students reading this). No offence intended.

The dc current carrying capacity is proportional to cross-sectional area, and not related to cable length, but the cable resistance increases with cable length.
{Resistance = resistivity x length / cross-sectional area}.
This means that the long thin cables have a higher resistance and this does reduce the current through the starter motor from a fixed voltage source, compared to using a shorter or fatter cable.
The cable could still carry the higher current if the source voltage was increased to compensate for a longer cable. The cable dissipates the extra power as heat.

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Yes of course you are correct. Increasing the CSA or voltage is the answer. Those cables hanging from pylons across the nation are up to 400,000 volts so they can pass massive ammounts of amps down them.

KPat said:

Yes of course you are correct. Increasing the CSA or voltage is the answer. Those cables hanging from pylons across the nation are up to 400,000 volts so they can pass massive ammounts of amps down them.

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Hi.
Not strictly true. 400Kv for a given wattage will require far less current (Amps) than say at 15Kv. Take a 1 amp fuse it will blow at 1 amp whether the supply voltage is 12v or 240v.
Overhead cables are relatively thin at 400Kv, as the current is massively less than at 240v with the same overall load. Can you imagine the diameter at 240v of these cables.

The high voltage overhead lines are generally AC. This brings extra factors, e.g. 'skin effect', into the choice of cable size.
AC current mostly flows near the surface of the cable - and the 'skin depth' depends on the AC frequency. Exceeding this radius, the central core just adds weight and cost, with little benefit.

According to Wikipedia (https://en.wikipedia.org/wiki/Skin_effect) the skin depth is about 8.5mm at 60 Hz.

I think they use multiple (aluminium ?) strands (to account for skin effect) arranged around steel strands (for strength).

chr1s said:

The high voltage overhead lines are generally AC. This brings extra factors, e.g. 'skin effect', into the choice of cable size.
AC current mostly flows near the surface of the cable - and the 'skin depth' depends on the AC frequency. Exceeding this radius, the central core just adds weight and cost, with little benefit.

According to Wikipedia (https://en.wikipedia.org/wiki/Skin_effect) the skin depth is about 8.5mm at 60 Hz.

I think they use multiple (aluminium ?) strands (to account for skin effect) arranged around steel strands (for strength).

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Interesting they are bare conductors (no insulation). Birds can perch on them without getting electrocuted because they are not completing a circuit.

Well the new battery sorted the flickering lights but not the other issues so I guess that will be something else, I’m guessing perhaps a sensor somewhere may be causing the rough idle and kangaroo type behaviour……will have to wait and see what the garage says.