Warrior193

Definitely does not sound right to me - did you ask the dealer about this module being left in transport mode?

Try a DIY load test, first ensure battery is showing a reasonably high SOC, with the multimeter probes on the battery terminals get someone to crank the engine on the starter and note what the voltage drops to.

Hello, was the head and cam work a modification - or result of wear/damage?

Back EMF of the cell is what is limiting the charge rate - even a fully discharged L.A battery has a voltage of around 11.0 volts. Increased internal resistance is one of the enemies of secondary cells as it limits the available current in both directions - the other main problem is hard sulfation which reduces available reactive plate material and is caused by persistent low SOC. IMO this is where there may be an issue with the BCM limiting the alternator charging to around 75% in micro-hybrids (stop/start)

A secondary battery (E.g L.A, NiCad, LiPo etc ) is one that can be recharged by reversing the chemical process - as opposed to a Primary battery ('dry' cell) where the process is non-reversable.

A common misconception to think of a secondary battery as 'an energy store' - it is more accurate to think of them as being a generator of DC current using a reversable chemical process.

Possibly it was serviced at an independent garage with no access to electronic service records - the inspection should give some indication if servicing has been neglected.

Probably no difference, does the inspection scope of both look similar?

Is it dealer or private sale? Does it have service history?

Hello, definitely worth having the inspection IMO.

Just a thought - has there been any LED type bulbs fitted recently?

That charger should be fine for your use, I use a larger Ring RSC608 for my Octavia. Very possible that your battery will not recover much after such a deep discharge.

Sudden battery failure is a frequent occurrence when the battery reaches end of life - especially if it has been giving some indications of weakness lately. Often happens with a sudden drop in temperature. Regular 5-mile trips are almost certainly not sufficient to maintain battery charge. Are you certain nothing was left switched on? At 2013, this vehicle is presumably not auto stop-start - is that correct?

+3 for manual, did not like the DSG when I was shopping for current Octavia - quite liked the TC boxed Passat I drove in Ontario, especially when using in manual mode. If the DSG manual mode was reversed so that it was similar to sequential, perhaps.

@Noda , have you resolved your problem?

Hello, welcome to the forum. Any random faults caused by battery disconnection and reconnection should clear themselves after taking the vehicle for a short drive. Did you carry out the battery adaptation (coding) after fitting the new battery?

At 2016 - so either MY16 or 17 depending on registration month, it will be.

If your battery is in fact the original factory-fitted one, it has done very well - there is often a date code stamped onto the top of the battery negative post giving date of manufacture (format is WW,YY) that will confirm battery age. Consider having the battery load-tested before replacement and base your decision on that.

I rather suspect a case of B.S here - the TSIs regen on a closed throttle, I can see absolutely no reason why this could affect your fuel use figures to the extent you say.

I was referring to standard BS1363 230 volt, 13 Amp household outlets which are the norm for 'granny charging' - 16 or 30 Amp outlets will be relatively uncommon in domestic properties unless installed for high-current applications.

Is this vehicle Kessy? - if so, and provided there is a responsible adult present in the vehicle at all times, leave the key with them.

I was referring to HV battery, but the same principle applies to LV. 230 volts AC is used by EV 'granny charger' in UK, hence the low charge rate.

Hello, welcome to the forum. The charger ampere rating is the maximum available on that setting - back EMF of the battery being charged will limit the amps actually being supplied - unless the charger is a constant current type unit. I'd think that a constant voltage type charger would be more likely for a lithium battery. What is your battery SOC when you are seeing 7 Amps as a maximum at the start of charging session?

The mandatory recall was for North America - involved approx. 250 000 1.4TSI Passats manufactured between 2016 and 2018. No recall (or even TSI) AFAIK issued for Europe.

Your symptoms for warm start issues sound very like ones I have seen reported where the cam or crankshaft sensor was found to be the cause.