BigEjit

Perfect! (Standard SLI flooded battery.) If the voltmeter shows 10.5v +\- 0.3, it’s a shorted cell ref issue No 1 above, return it to the retailer for an exchange. You will need a battery charger if the voltmeter shows any other voltage below 12.2v and a charge time up to 24 hrs if showing something like 5v. Ref 2, 3, 4 above. Once charged and you still have a problem, you are looking at issues related to No’s 2 and 3 above (most likely No 3).

Things to check, First thing, If you have access to a digital volt meter, what is the battery voltage currently? Are there any accessories plugged into the vehicle or added to the electrics, quick and easy to check. Possibly looking at one of the following reasons. 1, Internally shorted battery (New battery internal faults show very quickly within the first few engine starts) 2, Goosed alternator/charging circuit fault. 3, Something in the vehicle not switching off discharging the battery. 4, The battery wasn't that well charged to begin with and is now discharged from not having enough engine run time. Also, stick up a photo of the battery so we can see what it is.

A very thin film of Vaseline helps it slide in or press it down into the channel.

In the same way stop/start can be auto-inhibited on a stone cold engine, you could argue that would also apply when it is at the upper end of operational temps (if you manage to cook the engine that much you can get it into an inhibit state). After conducting hot climate cooling testing at OEM level early 2000’s, you need to really rag an engine in top gear on full throttle for at least 20+ mins without lifting to get anywhere near maximum temp limits. The mid engined cars I ran back then would de-rate the engines a little until the oil temps dropped sufficiently to allow max power again so it should easily be the case now to have more control limits in place. Front engined cars back in the day couldn’t even trip the upper temp limits due to efficient cooling systems. So don’t worry, it’s not going to cook itself if stop/start cuts in.

D52 is the wrong size battery for the car. It’s way too small. The original part no is 6R0 915 105 B and quite a bit larger.

So it is definitely not it’s first battery, this one is it’s second aftermarket supplied part. The paint mark on the negative clamp is not on the surface of the tightening nut and it has been slightly overtightened as the gap in the clamp has been closed up too much. It also looks too small for the insulation wrap. D52 is in the VARTA catalog for mk2 Octavia 1.4 without stop start. Ideally if you want another AGM, the Silver Dynamic 096AGM is best fitment for Mk3 Octavia 1.4. (Short code E39) Otherwise EFB Blue Dynamic 096EFB is the cheaper option for stop/start. (Short code N70) Before ordering, check the size of the battery on the VARTA website so you know it will fit in the battery box to be absolutely sure it’s correct. Whatever replacement you choose, I suggest you get it coded into the vehicle Just in case it was not done correctly when the current battery was fitted.

@haris Can you tell us what exactly you currently have on your vehicle? VARTA Silver Dynamic are not fitted by VW group on the production lines. They are only supplied as aftermarket parts or direct to small volume vehicle manufacturers. A photo of your current battery will be perfect. The reason I ask is the battery you described doesn’t exist on the fitment listings for your vehicle.

You are pretty close to the truth there! The primary reason for coding in the new battery is to select the correct charging strategy map for the battery technology type being installed to optimize its performance. There has to be an element of system self learning through the battery monitor relating to battery condition, (State of charge, State of function, Depth of discharge, Temperature compensation). So in theory, swapping 'like for like' batteries without coding won't have long term consequences and everything will be fine after a few hundred miles or so. No two identical batteries work in precisely the same way and certainly not if using a generic aftermarket battery vs the OEM optimised unit. Swapping EFB to AGM for example without coding won't mean that the battery will immediately fail/explode and the car do strange things, it still a 12v battery and will discharge and recharge as normal. It's just the optimised charging strategy won't be in place for maximizing the battery life and hidden operational features like the desulphation/reconditioning cycle timings and duration won't be correct either.

There are 2 ways to take a reliable reading. Disconnecting the battery and use a decent digital volt meter across it is the ultimate best way. Second best way is to connect up a digital meter to the battery and close the bonnet with the device on the windscreen/outside the engine bay. Unplug every accessory from inside the cabin, close and lock the doors. Leave it for approx 15 to 30 mins for all the modules to go to sleep and then check.

So is it rust pushing through the paint or something like bubbles trapped in an E-coat layer of the factory finish? If it’s not rust, I would be inclined to leave it well alone regardless if a repair was offered or not as messing with the paint in that area won’t be unnoticed and could lead to issues later on. I’d be still upset if it was rust, though.

Any 12v battery can be discharged but AGM is more resistant to the sulphation damage caused by it. There’s a greater chance of recovering an AGM over an EFB, likewise EFB over Standard flooded battery but it’s still better to prevent discharging or permanently running at the low end of the 12v to 13v operational window of any battery in all cases. Vehicle electrical circuit temporary fluctuations between 6v and 15v are normal. Resting voltage below 12.0v is not.

AGM are more durable than the equivalent EFB. They take more abuse electrically and are more resistant to vibration damage.

Heck. Missed out on a bargain there. 🤦‍♂️