charging woes part IV 'The Wrath of Tim'

[Ross]

Tim,
I think your only problem is a weeny battery and a tired starter.
You are ambitious enough to have a go at the starter me thinks. Usually a thorough cleaning and maybe new brushes with a solenoid is all that's required.
I've NOT done a BM starter so look into parts availability and difficulty reinstalling brushes. On GMs the solenoid can even be "freshened" by rearranging some of the contacts, not sure if this will work on the Germans.
If you want the cluster I'll try popping it in one of my '89s to see what does/doesn't work.

[Ferret]

Sorry I forgot the 525is use small batteries.
At 16mA, a 65Ahr battery should take a good 10-14 days to lose 25% of its charge...
(using the 25% capacity rule of thumb, 40 days if using 100% calculation)

What're the liquid levels like in the internal battery cells? Pop the caps and have a look in each cell to see how much liquid is in there.

There's something not right here somewhere...

As a rule of thumb for lead acid batteries,
~12.6-12.7V is fully charged
~12.5 is approx 70% charged
~12.3 is approx 50% charged
~12.2 ~ 40%
~12.1 ~ 30%
~12.0 ~ 25%
~11.5 ~ 0%

The battery should spin the starter from 12.5 like a rocket... I'd start eyeing up the starter.
Try cranking the car over and seeing what voltage the battery drops to while cranking.

I find it interesting from your original post that the battery appears to be losing charge while just sat still outside and out of the car.

[tim eh?]

I admit the battery is small - but it is listed as stock, and I only have an m20 with no wacky extras. And it used to work really well.

The battery I swapped in was a 550A/hr but pretty new. I got the same results. I will try to find a bigger battery to borrow.

I'll try and upgrade, I have a feeling it will be a hassle, I went there already once.

Not sure if I want to pull the starter apart today



it would be kind of funny if all this was just a dead battery.

[Ferret]

Reading Ross' post I think he's more than likely correct...

If your car has an undersized battery fitted (CCA underrated) and is going through harsh icy winters with a tired starter, the battery will die a very rapid and premature death. I seem to remember that when you had it CCA tested it only just passed the test? It may be a good idea to get the bigger battery in and adjust your battery tray to take it.

16mA I'm pretty sure is well within drain tolerances for any stationary E34.

The other way to test this by the way is to put a small 100mA fuse in the line, and leave the car drawing 16mA. If the current surges during the night for whatever reason, the fuse will blow by the morning. Dont lock the doors though

[tim eh?]

What're the liquid levels like in the internal battery cells? Pop the caps and have a look in each cell to see how much liquid is in there.

[...]
The battery should spin the starter from 12.5 like a rocket... I'd start eyeing up the starter.
Try cranking the car over and seeing what voltage the battery drops to while cranking.

I find it interesting from your original post that the battery appears to be losing charge while just sat still outside and out of the car.

at 12.5 it does spin like a rocket... 12.0 not so much I would assume that is normal.
from obc#9 it drops to about 10.5 when cranking.

I am leaving the battery out a bit longer I think will test the voltage drop for a bit. Case is translucent... fluid levels good i think... i tilted it a bit for this photo.

[tim eh?]

The other way to test this by the way is to put a small 100mA fuse in the line, and leave the car drawing 16mA. If the current surges during the night for whatever reason, the fuse will blow by the morning. Dont lock the doors though

nice test - will do

the battery was the initial suspect.

but the load test made me look elsewhere.

if it turns out to be the battery at least I will have learned a lot about the car, i can do alternators in pit-stop times now.

[Ross]

I would somehow do this in parallel with the circuit before disconnecting the main feed due to the capacitor's draw as mentioned before. Ferret?
Can you have that starter checked for how much it draws? I'm beginning to suspect all these checks are academic and a tired starter motor is sucking large current

[tim eh?]

I would somehow do this in parallel with the circuit before disconnecting the main feed due to the capacitor's draw as mentioned before. Ferret?
Can you have that starter checked for how much it draws? I'm beginning to suspect all these checks are academic and a tired starter motor is sucking large current

yes, i would like to test the starter 4 sure if there is a way.

would the starter be such a pull on the system when it's not cranking tho?

can i pull the starter relay with the engine running?

it cranks like new when the battery has charge.

i have the very occasional warm start problem but it is not a starter problem i suspect the fuel pressure regulator thanks to a couple smart members here.

[Ross]

haven't you said the battery loses while disconnected?? If so then def. a battery issue, that, coupled with a hungry starter....
If the warm start problem is slow cranking look to the starter.
Sending the instrument cluster via USA's finest government agency per your request.
Is this now an official cluster ****?

[tim eh?]

haven't you said the battery loses while disconnected?? If so then def. a battery issue, that, coupled with a hungry starter....
If the warm start problem is slow cranking look to the starter.
Sending the instrument cluster via USA's finest government agency per your request.
Is this now an official cluster ****?

i have suspected the battery all along, batteries die easy here... i took it back already once but didn't stay because they said it was going to take at least 4 hours to charge it enough to do a proper test. i also had my mechanic do a load test... but at that point i was less-informed and i have no idea how big a test he did. i am starting to think he was trying to get me out of his hair - he was very dismissive about me replacing the alternator with a 'dns2000' as opposed to a bosch, seemed convinced it was a bad alternator (i can understand why given bmg's experience). i'm guessing he ran about 250ca through it just to show me the 'battery is good' screen.

so i'm ranting now... read at your peril - **** i mean why does it have to be such a pita for me to ask a mechanic, who i take my car to regularly and pay $70/hr to change the oil, to properly test my battery? i mean, wtf does he expect me to do? i've been pissing around for two weeks, replaced the alternator twice, torn my dash apart, installed engine to chassis grounds, sat around measuring battery voltage, just because he was pressed to do so many sets of snow tires. i know.. the next guy in line was paying $1500 (he said) for some fancy lights on his audi... i guess a battery test is peanuts - but seriously wtf does he expect me to do? i don't have a choice he knows that, he's austrian and he works on cars in montreal he knows winter. ****.

warm start problem is fuel related and very very rare.

looking forward to ****ing with your cluster ross