Battery Life

[juan27]

Got a 2017 VRS 245 Manual (F/L) 50K miles on the original battery. When are people finding batteries fitted from new on the Octy 3 need replacing? Car doesn't do much stop/start as generally used out of heavy traffic.

[indars]

My TDI still have original Varta AGM. 150'000km / 6.5 years. All fine, StartStop disabled.

[ords]

Mine is original from Jan 2013. Has a healthy cranking speed even after not being used for a few weeks. Stop/start always enabled.

[Ootohere]

Apples and pears.

 

I would expect a 2.0 TDI to possibly take more starting than a 1.6 TDI or even a 2.0 TSI.

 

But you have location location location other than if Stop / Start is disabled which i think makes little difference.

 

Winter length and low temperatures or not much of winters.

Even though you do long trips how often a day is the vehicle started or run with a load on the battery, nights, days, lights on etc etc.

 

The only way to know about how long a battery might last is with pretty much the same cars and batteries being used in the same way, 

so that might be Fleet, Taxi firms or the likes, but then there are still differences, those that sit idling or stop an engine because they are going no place.

[SC03OTT]

2017 vRS TSI here.  60k miles and on the original battery. Stop start always disabled on startup. Original discs and pads as well if you’re interested 🤷🏻‍♂️ (will be next years task). 

[WillRB]

2 hours ago, SC03OTT said:

2017 vRS TSI here.  60k miles and on the original battery. Stop start always disabled on startup. Original discs and pads as well if you’re interested 🤷🏻‍♂️ (will be next years task). 

Wow impressive with your disks and pads, mine had to be replaced at 50k, just looking ahead when driving helps prolong them so much.

[paulski]

96k miles on my 2.0tdi Dsg still on original battery. Mixed driving, no issues with start stop operating. 

[indars]

On 28/09/2023 at 17:43, WillRB said:

Wow impressive with your disks and pads, mine had to be replaced at 50k, just looking ahead when driving helps prolong them so much.

With my dynamic (but not sporty) driving style, replaced front original discs/pads on 125k km and rear on 143k km.
To be honest, both front and rear could last extra few months before reaching min dimensions- but I dislike when dust rubber of brake piston hangs out too much.
Same was on my previous car Mk1 Fabia, where every front brake set lasted at least 100k km (but with rears drums it's another story).

[EnterName]

On 28/09/2023 at 08:34, juan27 said:

Got a 2017 VRS 245 Manual (F/L) 50K miles on the original battery. When are people finding batteries fitted from new on the Octy 3 need replacing? Car doesn't do much stop/start as generally used out of heavy traffic.

I have a 2019 2.0TSI and I don't think the battery liked the car being sat on a lot for 6 months during lockdown.

Stop start usually doesn't actually work unless it's had a really good run first. I disable it as it almost never seems to be in the mood to work when needed and sometimes kicks in when not.

Might be another fault, but I don't think my car's battery benefitted from the 6 month hiatus.

[RoddersUK]

2017 2.0tsi 32k needed changing in 2021

 

[Warrior193]

Warranty replacement Moll EFB in 2016, still testing as good battery and I always use stop/start where possible.

[juan27]

Thanks for responses. I appreciate battery life depends on many factors but I was trying to get a feel if the beefier batteries fitted for stop/start are showing any trend towards lasting longer (or indeed shorter). 

[Warrior193]

I would add a comment on the 'smart alternator' Most of my mileage is relatively short trips commuting to work and I believe that the undercharging buffer allowing for regenerative charging, can be detrimental to battery life.

I recharge my battery fully when the stop/start system starts flagging the 'high power use' message. Consider it only a slight inconvenience with the micro-hybrid technology - it would be great if VAG created an algorithm for the charging system that identified when regenerative charging was not likely. 

Excess energy could always be dumped - rather like the regenerative braking system on diesel-electric ore trucks.      

[Rodge]

I think the fact that the "smart" alternator stops charging when the battery is nearly full, instead of continuing to try to charge a full battery, should be better for the battery.

[Warrior193]

6 minutes ago, Rodge said:

I think the fact that the "smart" alternator stops charging when the battery is nearly full, instead of continuing to try to charge a full battery, should be better for the battery.

But the 'smart' alternator system doesn't - it normally only allows 60 to 75% charge maximum - apparently to allow capacity for regenerative charging, meaning, with mostly short runs, the battery is never fully charged.   

[Gerrycan]

Does anyone know how this mild regenerative braking actually works?

I try to drive economically, which means I avoid actual brake application as much as possible.

I figure that using engine braking uses no fuel and is still turning over the alternator but does this mean that if brakes are applied, however lightly, this will signal the alternator to create a greater output to the battery and more resistive load?

Does that mean that someone who drives like me will not be adequately charging their battery especially if being drained by engine stop/start?

 

My basic spec 2014 manual 1.4tsi Octavia does not have stop/start, I'm not even sure it has regen braking. In fact I have  remarked many times in this forum that engine braking is markedly less than other car I have driven. This is excellent for fuel consumption on the flat but a bit of a pain on long moderately steep descents where engine braking even in low gears contributes little or nothing to speed control and I have to use brakes more than others around me or any car I have used before. Yes I know that what brakes are designed to do but I have never 'depended' purely on brakes as I do in this car.

Not having stop/start means I have a relatively inexpensive non AGM/EFM battery and mine needed replacing at just over 5 years, but gave plenty of notice. Theoretically I should be on the lookout for indications of ageing in the Australian made replacement but there are no obvious issues as we approach our summer.

As a footnote I do not have any appropriate software or dongle so I did not update the system when I changed the battery.

I do not know if I have the mild regen braking of the more 'advanced' cars but quite like the relatively simplicity of this car and its consequent lack of issues to date.

 

Edited 6 October, 2023 by Gerrycan

[Breezy_Pete]

@Gerrycan I believe if you don't have start/stop or an AGM/EFB battery then you will have a fixed-voltage alternator which can do nothing with respect to regenerative braking.

 

[Warrior193]

7 hours ago, Gerrycan said:

Does anyone know how this mild regenerative braking actually works?

I try to drive economically, which means I avoid actual brake application as much as possible.

I figure that using engine braking uses no fuel and is still turning over the alternator but does this mean that if brakes are applied, however lightly, this will signal the alternator to create a greater output to the battery and more resistive load?

Does that mean that someone who drives like me will not be adequately charging their battery especially if being drained by engine stop/start?

 

My basic spec 2014 manual 1.4tsi Octavia does not have stop/start, I'm not even sure it has regen braking. In fact I have  remarked many times in this forum that engine braking is markedly less than other car I have driven. This is excellent for fuel consumption on the flat but a bit of a pain on long moderately steep descents where engine braking even in low gears contributes little or nothing to speed control and I have to use brakes more than others around me or any car I have used before. Yes I know that what brakes are designed to do but I have never 'depended' purely on brakes as I do in this car.

Not having stop/start means I have a relatively inexpensive non AGM/EFM battery and mine needed replacing at just over 5 years, but gave plenty of notice. Theoretically I should be on the lookout for indications of ageing in the Australian made replacement but there are no obvious issues as we approach our summer.

As a footnote I do not have any appropriate software or dongle so I did not update the system when I changed the battery.

I do not know if I have the mild regen braking of the more 'advanced' cars but quite like the relatively simplicity of this car and its consequent lack of issues to date.

 

@Gerrycan My understanding is the regenerative braking is from the alternator ramping up its output in regen conditions - this requires the charging system to leave available capacity in the battery.

Clearly the braking effect will be limited as the max. output of the alternator is a little less than 2000 watts (2.6hp) 

 

[Warrior193]

I suspect, but do not know for certain, that non stop-start vehicles will not have regenerative braking.

I think stop start and regen braking both require EFB or AGM batteries. Without the specialised battery or charging system, there should be no need to adapt a replacement battery into the system. 

[J.R.]

8 hours ago, Gerrycan said:

In fact I have  remarked many times in this forum that engine braking is markedly less than other car I have driven.

As previously proposed I doubt that you would feel the engine braking from an alternator, the mechanical engine braking is a lot less than before for fuel economy reasons, the further you can go down a hill with your foot off the accelerator the further up the momentum will carry you before needing fuel again.

 

I deliberately did not say a closed throttle because back in the day that was what happened together with fuel still being dragged through the carburettor jets, the vacuum created by the closed throttle was a very significant part of the engine braking (not so on a diesel) modern engines not only cut the fuel off completely above a threshold, say 1250rpm) but also open the fly by wire throttle body to reduce the vacuum and hence engine braking.

 

 

[Gerrycan]

Thanks for the replies.

I was pretty sure I did not have 'mild regen braking' but I was curious as to how intelligently programmed it was to actually make any sort of difference or whether it was  just another marketing gimmick for those that had it, and whether it was partly responsible for the short battery life that some have experienced?

 

@J.R.'s description of the engine operation ties in with my understanding that the direct injection allows it to operate without a throttle like a diesel does. Does this mean that the versions of the 1.4/1.5tsi that have ACT, where two cylinders valves are closed, have even less engine braking effect?

 

My car does actually have a very intuitive stop/start system which only operates when the operating system recognises that the car is stopped for a reasonable length of time such as at a known long traffic light cycle or the rare occasion when I get caught at a crossing to let a kilometre long freight train through. Yep, you guessed it, I turn off the engine with the ignition key and manually restart seconds before the lights change  . My wife hates me doing it .

 

A couple of years back my wife and I fluked a two week break between Covid restrictions to the Northern Territories and also scored a hire car upgrade to a Toyota sedan hybrid, my first real experience with one.

One of the things that surprised me with the Toyota was that during purely regenerative braking from high speeds (130kph speed limits there), into a much bigger battery, there was (again) far less retardation than I expected. Toyota must have recognised this as there was a gear lever option to add engine braking into the regen process (for steep hills?).

Another surprise was how stupidly economical it was at those high speeds on flat roads where the hybrid functions contributed virtually nothing. A tribute to the efficient Atkinson cycle engine and the CVT transmission.

If an estate version was sold here I would have bought one when we got back , but the Corolla sedan and even smaller hatchback did not quite cut it after living with the Octavia estate Tardis-like interior for so many years.

[J.R.]

39 minutes ago, Gerrycan said:

Does this mean that the versions of the 1.4/1.5tsi that have ACT, where two cylinders valves are closed, have even less engine braking effect?

I have not studied them but would say that there would be less load from the valve springs not opening and closing.

 

Are the valves closed or partially open in the situation you describe? Closed valves would create engine braking and also draw engine oil up past the rings.

 

I got my first car for a bargain price because the seller my BIL, 10 years older than me said the engine was foutu, running on 3, smoking and rattling like a pig, his diagnosis piston and big end failure. I knew better and in 5 minutes had it running like a jewel, well as much as a Vauxhall Viva engine could, without spending one penny, the stiffnut tappet adjuster on an inlet valve had unscrewed, I pinched it up in the vice and reset the valve clearance, no misfire, no more oil burning, no more rattling.

 

He was incandescent with rage because the precocious cocky s0d that I was at 17 took great pleasure in telling him my great news!

[Warrior193]

1 hour ago, J.R. said:

I have not studied them but would say that there would be less load from the valve springs not opening and closing.

 

Are the valves closed or partially open in the situation you describe? Closed valves would create engine braking and also draw engine oil up past the rings.

 

I got my first car for a bargain price because the seller my BIL, 10 years older than me said the engine was foutu, running on 3, smoking and rattling like a pig, his diagnosis piston and big end failure. I knew better and in 5 minutes had it running like a jewel, well as much as a Vauxhall Viva engine could, without spending one penny, the stiffnut tappet adjuster on an inlet valve had unscrewed, I pinched it up in the vice and reset the valve clearance, no misfire, no more oil burning, no more rattling.

 

He was incandescent with rage because the precocious cocky s0d that I was at 17 took great pleasure in telling him my great news!

I seem to recall that the inlet and exhaust valves remain closed in 2-cylinder mode. The cam lobes are moved away from the followers.

[Warrior193]

2 hours ago, Gerrycan said:

Thanks for the replies.

I was pretty sure I did not have 'mild regen braking' but I was curious as to how intelligently programmed it was to actually make any sort of difference or whether it was  just another marketing gimmick for those that had it, and whether it was partly responsible for the short battery life that some have experienced?

 

@J.R.'s description of the engine operation ties in with my understanding that the direct injection allows it to operate without a throttle like a diesel does. Does this mean that the versions of the 1.4/1.5tsi that have ACT, where two cylinders valves are closed, have even less engine braking effect?

 

My car does actually have a very intuitive stop/start system which only operates when the operating system recognises that the car is stopped for a reasonable length of time such as at a known long traffic light cycle or the rare occasion when I get caught at a crossing to let a kilometre long freight train through. Yep, you guessed it, I turn off the engine with the ignition key and manually restart seconds before the lights change  . My wife hates me doing it .

 

A couple of years back my wife and I fluked a two week break between Covid restrictions to the Northern Territories and also scored a hire car upgrade to a Toyota sedan hybrid, my first real experience with one.

One of the things that surprised me with the Toyota was that during purely regenerative braking from high speeds (130kph speed limits there), into a much bigger battery, there was (again) far less retardation than I expected. Toyota must have recognised this as there was a gear lever option to add engine braking into the regen process (for steep hills?).

Another surprise was how stupidly economical it was at those high speeds on flat roads where the hybrid functions contributed virtually nothing. A tribute to the efficient Atkinson cycle engine and the CVT transmission.

If an estate version was sold here I would have bought one when we got back , but the Corolla sedan and even smaller hatchback did not quite cut it after living with the Octavia estate Tardis-like interior for so many years.

I once hired a Subaru Legacy in Oregon, it had the chain-driven CVT, with the (IIRC) 8 speed steps in manual mode - I really liked it. Used it mostly in manual mode, but cooked the brakes a little bit on a very long down grade because I didn't kick it down enough on the paddles.  

[J.R.]

2 hours ago, Warrior193 said:

I seem to recall that the inlet and exhaust valves remain closed in 2-cylinder mode. The cam lobes are moved away from the followers.

Then the piston would be creating a partial vacuum on every downstroke sucking up air past the piston rings and then compressing it on every upstroke, good for engine braking, not so good for the health of the engine and the pumping losses would no doubt exceed any fuel saved.

 

But indeed that is what I have also read.