AGM Batterie in ältere Fahrzeuge? | Posts 16+

FabiaCombiTDI wrote:

As is often the case, this isn't about being particularly clever or wanting to use a battery for 14 years. Rather, it's about me simply KNOWING what's up. There isn't much information available online. And when there is, it's usually in sailing boat forums, but those are for completely different applications of AGM batteries.

Have you looked into this before?
http://www.microcharge.de/forum/
There's a lot of knowledge surrounding batteries and charging methods.

So, the BMW had a charging voltage of 14.8V today after driving 30 km without the start-stop system engaged. Exide confirmed over the phone that 14.4 to 14.8 is the recommended charging voltage. Several shops also state this online.
Given that the current battery test conducted by ADAC reveals a poor performance for conventional batteries, I will be subjecting the Exide AGM 70Ah battery to a long-term test.

By the way: The Polo only has a start-stop system when the hill descent assist is activated.


Regards,

Edit:
I just checked the "charging voltage" of my battery again. After starting the engine in -11°C (-12.8°F), the multimeter showed 14.7 volts. After driving 10km (approximately 6 miles) and with the engine only partially warm, the multimeter displayed 14.35 volts. Since I have very few electrical consumers and the battery was connected to a charger for an extended period three days ago, I would assume that the battery was already fully charged at that point.

14.4 - 14.8 Volts charging voltage, according to Exide - I need qualified opinions - regarding the topic of .

THANK YOU.

FabiaCombiTDI wrote:

I just measured the "charging voltage" of my battery again a while ago. After starting the engine at -11°C, the multimeter showed 14.7 volts. After driving 10 km and with the engine only partially warm, the multimeter display still showed 14.35 volts.

This is probably the temperature compensation that the regulator calculates based on its ambient temperature, and (99% of the time incorrectly) assumes that the battery acid is at the same temperature.If you're interested in learning more, during your next longer trip, try recording the voltage of the auxiliary battery (Ubatt). It should gradually decrease throughout the journey. The voltage levels should be approximately 0.08V apart; therefore, according to the multimeter (MM), you should likely see about 4 different voltage readings on the display between 14.35V and 14.7V.

Okay, thanks Ulf. This temperature compensation is a really useful thing. It might make sense for a few minutes with a TDI engine, but with a gasoline engine...?

Then I guess I'll switch over to Running Bull.


Hi FabiaCombiTDI,

I am undecided between the following batteries:
Banner PowerBull P7209 72Ah - Rank 2 - ADAC 2011 -> approximately €90.
Long-term experience?

hello FabiaCombiTDI


Hi,

I can only warn you about this battery. I bought it because of the test results. This is the exact same battery that caused problems for ADAC during a test when they used a tampered-with battery. After numerous reports of issues with the 'winning' battery, ADAC investigated and found that 1.5 kg of material (active substance) was removed from the battery immediately after the test, which meant it no longer even came close to meeting the required cold start currents.I have a battery in it that is now 11 months old, and at -20 degrees Celsius, the perfectly functional 1.9-liter engine won't start anymore; the starter motor doesn't provide enough power.

And the amazing thing is: I put my 6-year-old Varta battery back in – it had been sitting unused for almost a year – and after charging it up, it started right up, albeit weakly, but without any problems.

And just to be complete, the LIMA device has been tested and is working perfectly, with no leakage currents.
It simply doesn't have enough juice to start a cold diesel engine.