When I realised the battery on my 2011 Superb Diesel was only 61 AH I thought it was a mistake. When I asked at the dealer they said it was not a mistake and the battery was adequate for my car and said something about "smart charging". I always believed it was best to have the largest battery the car would physically allow and put up with the increased weight! Further reading in the forum topics convinces me that I am right.

Reading the manual about replacing a battery I find "the new battery must have the same capacity, voltage (12 V), amperage and be the same size." Then, of course "....are available from an authorised Skoda service partner".

Before I click the 'buy it now' button, and admittedly being in fear of the dreaded CANBUS, I would like to know if it is OK to disconnect the battery to replace it and whether my "simply clever" Skoda will really detect and reject the 77AH Bosch battery I propose to install.

Please don't take this as a criticism of the car - it's great. The dealer..........?

Many thanks in anticipation for any advice.

77Ah shows the capacity of a battery and cant cause any faults. CANBUS is smart but sincerely I dont understand why should it monitor battery capacity ... starts to singal when battery capacity goes down and battery starts to fail?

IMHO there cant be much problems when replacing original battery with stronger one. Never had any problems with my previous cars.

One thread about Fabia battery upgrade: http://www.briskoda.net/forums/topic/219302-battery-upgrade-whos-done-it-advice/

Just replaced my Superb battery with a Bosch 74ah. - 5 year warranty, yatter yatter, the Genuine Skoda has already been back to the dealer last year as it let me down - they wouldn't do anything about it, so changed it myself.

Al.

Recently did mine

http://www.briskoda.net/forums/topic/255444-new-battery-needed-at-43-months/

On my previous MK1 Superb, Skoda replaced the battery one month short of it's third birthday, that is what I call service.

Thanks guys - the new one's ordered!

...being in fear of the dreaded CANBUS, I would like to know if it is OK to disconnect the battery to replace it and whether my "simply clever" Skoda will really detect and reject the 77AH Bosch battery I propose to install....

No you'll be fine.

What you will find is as follows:

- You may have manually open and close all windows to reset the pinch protection. Simply hold down the button until the window rolls right down, then pull up until the window closes completely This lets the controller learn the force to use to close the windows. If this force is exceeded, the window will reverse to protect the glass and prevent injuries.

- Your power steering light will come on orange. This will go away when you have made a few steering manoevres.

- Your ESP light or ABS light may come on. This should go off after you have driven a few hundred metres.

Regarding smart charging:

- Yes like all modern cars, your car has a multi-stage charger. After starting, the alternator voltage is held at about 14.4v to replace the energy lost when starting. When the current falls off, the voltage is dropped to around 13.6 volts to keep the battery 'topped up'. If you have a stop-start system or the new-ish power-recovery system it may work a little differently.

Why is a multi-stage charger better?

For a traditional alternator and solid state regulator, they usually held the voltage at around 13.8 volts. For your typical lead-acid (LA) or lead-acid-calcium (LAC) battery, this meant that the battery was only ever charged to about 75% of it's total capacity. As you can only discharge a LA or LAC battery to around 50% before it is irreparably damaged, the battery only ever was able to supply 25% of it's total capacity. For a 70Ah battery, this means it could only ever supply 17Ah. This meant that the battery was around 2-3 times the size it actually needed to be.

With the proliferation of cheap microprocessors, cars started to get a bit smarter with their charging. By supplying a higher voltage and therefore a higher current to charge the battery, the battery can be quickly charged to around 80% full. The float voltage 13.6 volts, which is lower than the traditional C20 voltage of 13.8-14 volts, can then finish charging the battery to 100%. We therefore go from a 25% useful battery to almost 50%. The battery itself can then be smaller as we can use more of the capacity.

The lower float voltage prolongs battery life and reduces gassing where the battery produces lots of hydrogen and in the process loses water. The reduction in gassing means that the battery can be sealed without blowing out the pressure vents, which again reduces water loss.

Further prolonging battery life is the CAN bus style cars, which turn things off after a time. Examples are the radio and interior lighting which are shut off after around 10 minutes of being idle. Totally discharging the battery damages it so by shutting off consumers after a while we prolong battery life. In the case where the car is idling but the alternator is not able to produce enough current to run all consumers and charge the battery, the car can also go into 'load management' mode where non-essential items such as the radio, PTC electric heater and seat heaters are shut off to ensure that the battery is not discharged and there is sufficient energy to run important items like headlights and the engine computer. These items are turned back on when the engine speed increases, allowing the alternator to supply more current. Load management usually only has to kick in after a cold start in very cold weather after a long glow plug cycle.

What's coming:

Li-Ion and Li-Po batteries like what's in your phone or laptop are already very popular in motorcycle circles, are around 1/4 the size of lead acids and less than 1/4 of the weight yet contain the same amount of energy. The life of a well-treated LA battery is around double that of a Li-Ion battery, but in practice, no one treats their batteries properly so the lifetime is the same, the cost is the same and the weight reduction is significant. I'd expect to see these commonly in car-sizes soon, especially with the push for weight reduction to reduce emissions.

wokwon - thank you so much for your analysis if the situation. As an electrical engineer with a basic knowledge of electronics, I am in awe of the canbus system. I do remember the charging of lead acid batteries and 2.3 volts per cell as a charging / float value. I appreciate your comments on Li-Ion batteries, and understand that they suffer to some extent from a high internal resistance resulting in heat production and reduced efficiency, although not enough to make them anywhere near as low as the power/weight ratio of lead acid. There is a great future to look forward to in battery technology. What an irony when we consider how far advanced electronics is!

At the moment, though, I still think my principle (inherited from my father who worked on WW2 aircraft) of fitting the highest possible capacity of battery, is correct.

I do look forward to Li-Ion car batteries, but hope they can cope better than my laptop battery (which will now do about 10 minutes) with being kept at 100% charge.

Many, many thanks for your post!

Yeah, wokwon is a god.

Yeah, wokwon is a god.

I'm not a reliable source for anything, quote me at your peril!

Re-setting most electric components after a battery change...

Understand that most electric components in modern cars need to reset themselves when the battery is replaced or dis-charched for some time, but is the ECU or engine management in the Skoda reset as well as in some other cars which adjusts for there driving style like my last Merc?

Re-setting most electric components after a battery change...

Understand that most electric components in modern cars need to reset themselves when the battery is replaced or dis-charched for some time, but is the ECU or engine management in the Skoda reset as well as in some other cars which adjusts for there driving style like my last Merc?

No nothing needs to reset although some lights will come on they reset themselves after a few hundred yards

Whilst some ecu's can self-learn they are very limited in their functions it's certainly not a concern

Thanks Richf...

Having received the new battery I have decided to get the new parts I think I will need before I start. I think I will need a new tray, but not sure. I am almost certain I will need a new jacket as the new battery (096) is longer than the standard 61AH one. At first I thought I would adapt the parts to fit, but since the car has a lot of warranty left I did not want to give the dealer any kind of excuse to refuse me repairs (but absolutely nothing has gone wrong in the first 18000 miles as expected from my previous VW group experiences).

I wonder if anyone can help with part numbers or guidance.

Not sounding out of place here, but WHY buy a bigger (physical size) battery?

How about returning it, and buying one of these

It's 74 AH Bosch, has a 5 year warranty, lives in the same place as the old one, and is the same physical size so can fit the same jacket.

I know, as it's what I put onto mine.

And with the BriSkoda discount, is around £75 from EuroCarParts.

Al.

How do you get the Briskoda discount from EuroCarParts

Deja vu!!

http://www.briskoda.net/forums/topic/258992-is-the-octy-vrs-cr-170-diesel-battery-not-up-to-the-job/

Not sounding out of place here, but WHY buy a bigger (physical size) battery?

Al.

Thanks Al. The standard battery on my car is about 245 long and 190 high, so to get a larger capacity battery it had to be longer. The one I've got is 77AH, 278 long and 190 high, a Bosch S5.

ChrisRs - I had read your story. Of all the advice on your topic, I still think that to fit the highest capacity battery is the best and certainly the first thing to try. In fact it was reading your topic that finally decided me to upgrade, and I haven't had a problem with the tiny battery yet. I think manufacturers have taken weight/cost reduction too far and increased the risk of more people having your problem. Frankly, the dealer's solution of trickle charging is ridiculous. As you can't have been warned that your car wouldn't be suitable for your kind of driving/use it is NOT FIT FOR PURPOSE! They should be made to solve the problem at their cost - not tell you to use a trickle charger! Oh, and I don't suppose they offered to buy you the trickle charger either!

I suppose you have solved the problem by now and I would be interested in how.

Peter

I havent really Peter

I have bought a Battery Charger..but not a trickle one

The dealers wont move from standard Skoda parts even when proven that parts are not compatible with the circumstances

Simple reason it seems to me....The fitting of 61aH batteries are a cost cutting exercise and are OK for 90% of the year unless youre a motoway muncher.

My low mileage and cold weather is not compatible with that battery in the dark nights of winter

I'm going to keep the battery for now and see how it goes.

If it fails me again..I WILL be getting another ...and will try to recoup that from Skoda

Thanks Al. The standard battery on my car is about 245 long and 190 high, so to get a larger capacity battery it had to be longer. The one I've got is 77AH, 278 long and 190 high, a Bosch S5.

Now that's interesting... as my Superb (2010 4x4 170) came with a 70 AH battery.. I've just checked it, as i still have it.. hence the 74 AH Bosch S5 fitting without issue...!

Weird!

Al.

OK Al. I think its weird that Skoda thinks it OK to put a 61AH battery on any diesel.

Chris - Hope things turn out OK. I am still searching for info on the parts I need. I have found one very helpful person at Skoda Bradford who is the lady in the parts dept. I may have to ask her advice. I will let you know the outcome.

Used to live in Gilstead BTW.

Peter

I'm in Eldwick

Know the lady well...shes very good

Tell her Chris and Alan will be down if she doesnt help you

Chris - you may know a friend of mine in Eldwick who is very much into Jowetts - in fact he is a Jowett (maternal side, I think)

Cheers - have a good Christmas.

OK Al. I think its weird that Skoda thinks it OK to put a 61AH battery on any diesel.

What i mean is, why do i have a 70AH and you have only a 61AH? (i have a 170 Diesel)

to be honest tho, it shouldn't make a difference, the 61AH battery should be fine; i think it's just of poor quality.

Al.

I think the battery on mine is a Varta which have a good reputation, but not as good as Bosch as far as I know. The two engines are very similar as well, the biggest difference being a bigger turbo on the 170 (again as far as I know) so they should not need any more power to start, because what you do usually get with a larger AH capacity is increased "cold cranking amps", capable of dealing with increased compression ratio and cold oil (and cold battery as well). As I see it the main reason why a diesel usually has a bigger battery than a petrol engine is the increased compression ratio and to cope with the drain of the glowplugs as someone explained on the other topic.

The 61AH battery is a cost cutting exercise too far, no doubt about it - and it must be leading to hundreds of cases like Chris's that we don't know about. More reason for someone to take some action I think. I wonder if any VW diesels have such a small battery - the standard one on my Passat 1.9 PD was 72 (over 8 years ago) and when I replaced it I got something over 80. I don't think Skoda would stand a chance in court if someone like Chris made a case for the car being unfit for the purpose for which it was sold,

Something just sprung to mind as well - is the same spec sold in countries like Norway and Canada where temps get much lower than UK?

Peter