Technical Bigger battery?

[koalar]

I’m also thinking a slightly bigger battery might solve the issue where revs drop when idle and turning lights on, use electric Windows, blower etc

Thanks

I don’t normally read the 500 section

Am I the only one concerned with this

Yes the engine may die while idling with a dead battery. No idea why

But

“revs drop when idle and turning lights on, use electric Windows, blower etc”

Is a new one on me.

As long as the battery is adequate it works. Bigger just means you are carrying more weight around.

In fact the revs normally automatically adjust for electrical load

 

[StevenRB45]

I don’t normally read the 500 section

Am I the only one concerned with this

Yes the engine may die while idling with a dead battery. No idea why

But

“revs drop when idle and turning lights on, use electric Windows, blower etc”

Is a new one on me.

As long as the battery is adequate it works. Bigger just means you are carrying more weight around.

In fact the revs normally automatically adjust for electrical load

I'd not be, had a Mazda with an old battery in most circumstances fine.

But in certain circumstances usually low speed manoeuvring shortly after start up on a cold day it would do this.

Normally the battery fills any gap between the what the alternator can provide and what is required. But when they get a bit weak they dump the load back on the alternator, which increases the resistance and pulls the revs down usually before the ECU has time to compensate.

More modern cars have load limiting to stop this, our current one will momentarily switch off or limit things like blowers or heated windows if it detects it's going to happen.

 

[koalar]

I'd not be, had a Mazda with an old battery in most circumstances fine.

But in certain circumstances usually low speed manoeuvring shortly after start up on a cold day it would do this.

Normally the battery fills any gap between the what the alternator can provide and what is required. But when they get a bit weak they dump the load back on the alternator, which increases the resistance and pulls the revs down usually before the ECU has time to compensate.

More modern cars have load limiting to stop this, our current one will momentarily switch off or limit things like blowers or heated windows if it detects it's going to happen.

In post one the original poster is asking if putting a larger battery will cure an idle problem

In my opinion the answer is no. Because if everything is working correctly the revs will not drop with a good standard battery especially if your just putting the turning lights on

 

[StevenRB45]

In post one the original poster is asking if putting a larger battery will cure an idle problem

In my opinion the answer is no. Because if everything is working correctly the revs will not drop with a good standard battery especially if your just putting the turning lights on

Agreed, new battery that is in spec should also fix it unless the car has underlying issues.

However said Mazda later received an upgraded battery, it was a petrol I fitted the one from a diesel. It meant in terms of starting etc it was significantly better than it had been than previously as more cca, it also took a lot more to dim headlights etc than it had previously. That car did have an electric hydraulic pump though for the power steering which absolutely brutalised the battery at low speed.

Gives a bit more headroom for days when you're using the heated windows...heated seats...all the blowers, lights, wipers and stuck in traffic and more headroom for the inevitable decline in performance over time.

 

[varesecrazy]

I helped my son when his old 307hdi refused to start

Took a towline, jumpleads AND a battery

It started in his ..'now quiet' .. works carpark with a tow easily ( failing starter..)

Got back to the Security gatehouse..
A 2002'ish Polo blocking the road .. 2 exhausted people pushing it

We helped push.. it would Fire

Idle for 5 seconds.. then stumble and Die


Flyby wire throttle was dead


Managed to sit MY spare battery in alongside theirs and it cranked and ran

'Are you going far?'.. 40 miles..!!

After offers of a trip to my place to permanently swap batteries..

I led them to Halfords.. and a new battery was fitted - all good


I was also shocked how tricky that could be you would be stranded..

I bumpstarted my 1st panda like a small 2stroke bike

 

[koalar]

Agreed, new battery that is in spec should also fix it unless the car has underlying issues.

However said Mazda later received an upgraded battery, it was a petrol I fitted the one from a diesel. It meant in terms of starting etc it was significantly better than it had been than previously as more cca, it also took a lot more to dim headlights etc than it had previously. That car did have an electric hydraulic pump though for the power steering which absolutely brutalised the battery at low speed.

Gives a bit more headroom for days when you're using the heated windows...heated seats...all the blowers, lights, wipers and stuck in traffic and more headroom for the inevitable decline in performance over time.

A battery with dead cells and resting at 11.2V

Blowers
Heated rear
Main beam
Fog
Reversing

All on

As tested on a Fiat Panda

Alternator still pumps out over 13V although adequate it’s well down for it’s normal 14.1

Older cars with idle control valves certainly use to drop then pick back up again when you added an electrical load.

You do have to be careful ordering batteries as they change specs depending on year and model

Anything around 220 CCA is fine up to start/stop on the Panda.

It’s counter intuitive but a large battery last just the same time as the correct size battery. Going oversize is the same as burning money

I helped my son when his old 307hdi refused to start

Took a towline, jumpleads AND a battery

It started in his ..'now quiet' .. works carpark with a tow easily ( failing starter..)

Got back to the Security gatehouse..
A 2002'ish Polo blocking the road .. 2 exhausted people pushing it

We helped push.. it would Fire

Idle for 5 seconds.. then stumble and Die


Flyby wire throttle was dead


Managed to sit MY spare battery in alongside theirs and it cranked and ran

'Are you going far?'.. 40 miles..!!

After offers of a trip to my place to permanently swap batteries..

I led them to Halfords.. and a new battery was fitted - all good


I was also shocked how tricky that could be you would be stranded..

I bumpstarted my 1st panda like a small 2stroke bike

Correct

never did discover why they do this

Here mine from 5 years ago

1.1 cold start idle problem | FIAT Panda (Mk3)

Girlfriends active has started to play up. Its difficult to start. If you take your foot off the throttle it stalls. If you hold the throttle down for a minute then it will drive fine. Multiecuscan says the desired idle is 1400 RPM but it starts at 750 RPM and lowers to 700 and stops...

www.fiatforum.com

Alternator is pumping out the correct voltage at startup but it will not idle. You can start the car with a jump start but if you can’t take your foot off the accelerator as it dies

 

[koalar]

I would have had done a few checks first

The original posters revs drop when you put the indicators on

They have recently fitted a Bosch 042 which should have last 10y as long as the car is used every week

I would be checking the aux belt, alternator voltage at idle and higher revs with and without the load of the rear heated window and blower

preform a voltage drop test on the earth leads

measure the battery resting voltage
and how much the voltage drops during cranking

The only time I have come across this is either cars with a faulty alternator. A fully charged battery goes about 15 miles but as any extra electrical load is added it cuts out. Annoying it’s usually at a junction as you put the brakes on. Or high resistance in wire. Put the headlights on and the side go off, put the brake on and the indicator flash quicker. You change the load and it has an effect somewhere else

It may just be the battery. Lead acid batteries don’t like not being fully charged. I wouldn’t risk a new battery until I had preformed some checks, but that’s just me.

I hope it is just the battery

 

[StevenRB45]

I would have had done a few checks first

The original posters revs drop when you put the indicators on

They have recently fitted a Bosch 042 which should have last 10y as long as the car is used every week

I would be checking the aux belt, alternator voltage at idle and higher revs with and without the load of the rear heated window and blower

preform a voltage drop test on the earth leads

measure the battery resting voltage
and how much the voltage drops during cranking

The only time I have come across this is either cars with a faulty alternator. A fully charged battery goes about 15 miles but as any extra electrical load is added it cuts out. Annoying it’s usually at a junction as you put the brakes on. Or high resistance in wire. Put the headlights on and the side go off, put the brake on and the indicator flash quicker. You change the load and it has an effect somewhere else

It may just be the battery. Lead acid batteries don’t like not being fully charged. I wouldn’t risk a new battery until I had preformed some checks, but that’s just me.

I hope it is just the battery

Seem to remember Bosch batteries have a 5 year guarantee (at least the last one I fitted did).

If OP has the receipt then it may be worth a shot at getting an exchange, it's not unknown for batteries that have sat on the the shelf to be a bit crap. Indeed the last Bosch I had was a silver and came with an indication on the top if it had gone bad in storage.

In terms of battery spec..the car will only ever draw what it can use so pre-stop start fitting a different battery isn't really going to mess with anything.

 

[Pugglt Auld Jock]

It looks like yet another pile of technology the offers nothing useful to the end user, but pays the dealers very cicely indeed.

Maybe MES can do the job which would be nice.

Absolutely. I was caught by this with the Ibiza last spring on our annual Devon trip. I'd known the battery was a little on the dodgy side because stop/start had packed in a few months previously, She was still starting and running just fine though so I decided to chance it. Of course it decided to drop us in it by refusing to start one morning at my sister in law's in the back of beyond on the edge of Exmoor! Luckily I'd got the ctek in the boot and a couple of hours on it was enough to get her started and I drove straight to the SEAT Dealer in Croyde where they fitted a new battery and coded it in for substantially over £200 - OUCH. I've since had some in depth conversations with a chap on the Cupra Forum, who lives near me, and he's experimenting with his VCDS (I have this but not with the latest interface. worked fine on my old Cordoba diesel but doesn't seem to access much on the Ibiza. Software all up to current spec so I think it's the interface which is the problem) Anyway this fellow thinks it's possible to use VCDS to "fool" the ECU into accepting a generic battery as replacement. I'm putting off investing in the interface until he lets me know how things are turning out.

Don't know if you can do it with MES but I also remember reading somewhere that Fiats are one of a few makes where the system resets itself when it detects a new battery has been fitted. It was some time ago that I remember reading this and it certainly seems to have been the case when we fitted a new battery to my boy's 2012 Punto which is a few years down the line form fitting now and working perfectly. I very much doubt if the Punto has "smart" charging though so maybe later models with this feature (which the Ibiza has) would require a reset via diagnostic equipment.

 

[vexorg]

What a convoluted thread when the OP only need to check the battery and then check the alternator. Very easy to do with a multimeter.

It's not the battery's job to keep everything alive at idle - it starts the car and fills in briefly while the alternator catches up.

 

[Pugglt Auld Jock]

It's not the battery's job to keep everything alive at idle - it starts the car and fills in briefly while the alternator catches up.

well, Yes-ish, and I say that because modern electric power steering needs a good battery to function especially at idle when alternator output is low.

 

[varesecrazy]

Regarding Coding at battery change

Ive recently swapped a New S-S battery on a 2018 FIRE 500

The 500's 4 year old battery onto a 2013 twinair panda

No fuss and S-S worked as expected within a day on both cars

 

[koalar]

What a convoluted thread when the OP only need to check the battery and then check the alternator. Very easy to do with a multimeter.

It's not the battery's job to keep everything alive at idle - it starts the car and fills in briefly while the alternator catches up.

Correct

Diagnose why


issue where revs drop when idle and turning lights on, use electric Windows, blower etc

Diagnose why it didn’t last

few years ago the factory battery died, so I went out and bought a Bosch 042 battery

Not throw a bigger battery in

A 220 CCA lasts 10y in my cars

 

[Pugglt Auld Jock]

Correct

Diagnose why


issue where revs drop when idle and turning lights on, use electric Windows, blower etc

Diagnose why it didn’t last

few years ago the factory battery died, so I went out and bought a Bosch 042 battery

Not throw a bigger battery in

A 220 CCA lasts 10y in my cars

I largely agree. However, I've found, over many years experience, that the more you have in reserve where batteries are concerned the better. At one end of the scale, a bigger battery will let you crank for longer when fault finding a non starter and it will give a longer "burn time" when one of the grandchildren leaves the interior light turned on without me you noticing. So, if it will fit and if there's not a great difference in price, i would always go for the larger capacity option - within reason of course.

 

[StevenRB45]

Correct

Diagnose why


issue where revs drop when idle and turning lights on, use electric Windows, blower etc

Diagnose why it didn’t last

few years ago the factory battery died, so I went out and bought a Bosch 042 battery

Not throw a bigger battery in

A 220 CCA lasts 10y in my cars

Definitely worth checking alternator... although it may be naïve of me to expect the battery light to illuminate if the car has a fault with the alternator.

Regards battery life though, 2 years ago would be the start of lockdown one pretty much. If it sat for months doing the odd five mile trip then battery isn't necessarily going to be in great condition.

A mate of mine bought a car it was delivered Jan 2020..he had to replace the battery last week it was stone dead.

In daily use yes 10 years...but in other circumstances less.

 

[vexorg]

well, Yes-ish, and I say that because modern electric power steering needs a good battery to function especially at idle when alternator output is low.

By that logic, if I continually turn the steering at idle then the car will die, I dont believe it will.

 

[StevenRB45]

By that logic, if I continually turn the steering at idle then the car will die, I dont believe it will.

You're talking about the difference between a transient load and a constant one.

A constant load the car will happily compensate for but a sudden random one like asking for Max torque from the electric steering motor is usually supported by the battery until the alternator catches up.

If the battery isn't up to the job it pulls the revs down as the load on the alternator is higher and the car hasn't had time to adjust to it. Keep twirling the wheel of will and the revs will pick back up to normal and probably go slightly the other way when you stop turning the steering.

 

[Pugglt Auld Jock]

By that logic, if I continually turn the steering at idle then the car will die, I dont believe it will.

The extra load may well drag the revs down temporarily but the ECU should very quickly detect this and cause the Idle correction valve to open up and restore (or possibly even increase) idle speed. Therefore I doubt if the engine would stall. Even on older cars with no idle air valve, simply a fixed throttle stop, probably won't stall because when the revs drop really low the torque demanded by the alternator will drop away and it's resistance to turning will reduce.

However the alternator, at engine idle speed, will not have sufficient output to balance the power demands of the power steering so, if your battery is poor, you'll loose the power assistance and this will be most noticeable when parking when large wheel movements with engine at idle speed is common. Of course there may be other demands on the system at this time as well, brake lights, radiator fan, aircon/heater fan, etc, etc which will only serve to compound the problem. Once the heavy load is removed the alternator will quite quickly recover the battery to some extent and the problems will go away until the next time a large current drain is placed on the system.

 

[vexorg]

No, if you are saying that the battery is necessary as the output of the alternator is low at idle, then I was not meaning stall, I was meaning eventually die as the battery will run down to a point the car cant run.

 

[koalar]

. Of course there may be other demands on the system at this time as well, brake lights, radiator fan, aircon/heater fan, etc, etc which will only serve to compound the problem. Once the heavy load is removed the alternator will quite quickly recover the battery to some extent and the problems will go away until the next time a large current drain is placed on the system.

The Panda will still charge the battery at idle with

The blower on max
The rear heated screen on
The main beam on

As that’s how I test my alternator

It’s a 100A alternator at 12V

Or 1200W although not at idle

Flyby wire does not have an idle control it’s all done via the throttle butterfly in a fraction of a second

The battery is permanently in the middle of everything so say an internal short will upset things


But an indicator or electric window dropping revs and a battery dying so soon. Points to either an underlying fault, car not used enough possibly more

But doesn’t point to requiring a bigger battery. In fact I have seen much smaller light weight 170 CCA race battery fitted to save weight in a 500 and that ran fine not that I would recommend it.