I appreciate all this info that I had no clue about, only dreaded lol.

She's been disconnected since I discovered she went completely dead except to start and move her (as it didn't make sense to allow a massive draw while connected) , and charge the battery each time. I've managed to improve the full charge stabilized no load voltage of the "not that old" battery from 12.18 to 12.49v with repeated "repair mode" charging using my Noco Genius g26000 charger.

Noco claims it's a microprocessor controlled de-sulfation charge cycle using higher voltages while disconnected from the vehicle as an attempt to improve battery status.

Next time I start her up I'll be sure the multimeter is on it so I can monitor voltage drop while cranking. I'll put more "repair" charge cycles over time while disconnected, hoping the voltage readings (taken after at least 8hrs with nothing connected) improve to closer to 12.6v if at all possible.

I also put the charger on the battery in normal "mode" while checking for the draw with the meter between the neg post and the ground cable because when I 1st started, it read ~4A then gradually dropped down in steps over time to a steady .25A, which I assume is what's draining it.

​​​​​​Thanks again Paul.

Jay

 

Jay,

I prefer to use the term Voltage Dip (Battery can't supply the Volts ) instead of Voltage Drop (Voltage difference between two points with a current flowing)

For reference here is the VoltageDip at the battery when cranking
(note: my volt meter has a MIN function and that is what I used)

LR2________11.07 Volts (New battery)
A4 2.0T_____10.64 Volts MFG --> April 2019
328i________10.20 Volts Original battery from 2015
Jetta 1.8T____10.53 Volts Original battery from 2015

If you are in the 11.0 Volts or higher while cranking then I would continue to use that battery

Below 10.5 Volts and it is time to consider replacement

Here is the link that I originally posted

https://www.freel2.com/forum/topic37...ht=voltage+dip

Good Luck

Paul

 

Thanks Paul, I think I might need it. I guess when the previous owner said it was a fairly new battery, I consider that to be even 4 years old (time flies), which is not that new in LR2 years lol.

Yes voltage dip makes more sense as voltage drop would be the drop seen between any resistance. I'd planned on getting back to working on it Thursday in between kitchen duties so will discover more then.

Hope everyone has a great Thankgiving holiday!

Jay

 

@p_gill @LR2driver @flybd5 @merlinj79 Dear Paul &co,

I have to thank y'all again & feel I owe you an update. I purchased everything you recommended, amp meter battery tester, loopback stuff but before contorting myself out in the weather further trying to pinpoint the exact problem, I discovered a remote kill switch solution so I tried the easy way out. After a few weeks and about 10 or so start cycles just to move her around, I ran into a no crank situation, not even a click. I think I created a bigger gremlin by installing that. After researching this site and trying so many things I got her to crank and she started right up. I vaguely remember after my cheap bluetooth OBD reader full reset using torque it resolved. So I applied some "noco genius" repair cycles on the battery and let her sit disconnected. After a couple months sitting I was amazed the battery still read 12.8v or so and she started right up. So I invested in a new windshield as when I bought her, someone had taken a hammer to it against the previous owner. After about a year or two of her just sitting, starting up and driving round the block occasionally and disconnecting power right after and monitoring the battery often...

I'm happy to report she's been a joy and 5-7 day a week daily driver for the last 5 months. I have lived with disconnecting the neg side when I get home. So easy. At work she can sit for 10-15 hrs and fire right up.. I've wired up a multimeter to the lighter socket plug to check charging occasionally. 13.8 - 14.45v each time. Before disconnecting, I religiously check and it's 12.7 -12.8 and after disconnecting, it always rises by .5-.8v It takes 3 min to do when I get home and 30 sec to reconnect the next morning, even in full darkness. I still intend to fix it properly but I've learned to live with the inconvenience so far.

This morning my dash went dead, no lights, gauges, odo, lcd display, door chime, blinker indicators but she started up and got me to work and home. Again this forum saved the day. I pulled passenger footwell fuse box fuses 4 & 8, tested and scraped off the fuse blades and reinstalled. Voila as soon as I pushed the fob in the chime came on because I left both F doors open to listen for that and everything works again (fingers crossed) I am just so grateful to this resource! Hopefully my long winded story helps someone else.

 

Well, good move confirming that the generator (alternator) is doing its job.
Sure, when the battery is hot, you may get readings above 12.6v.

But let it sit overnight and compare the voltage, before starting the engine, with the reading the night before.
When it dips to 12.4v, just replace the damn thing.

Unfortunate you need the cutoff switch though… but tracing those issues take a methodical approach and lots of time… do you have the workshop manual?

 

I wrote this on the other forum but you should read it

 

When you buy new fuses, get a major brand like Bussman or Littelfuse. The cheapo off-brand fuses are not reliably true to spec. (Years ago, Harbor Freight issued a recall of its automotive fuses.)

 

Doesn't AliBaba sell a cheap tester for this? 😎😎

 

Unfortunately, you can't test for quality. (But if they did have one, I would already have it ).

 

You can't test for quality??? Since when?