[nazali]

txs guy's at any time (according to my DVM, how accurate I dont know) has never read any higher than 12.4 / 12.5 ish. have read, to put headlights on for 2 minutes to get rid of surface charge, would anyone concur.

Hopefully my Solar bat tester will be more accurate and give me cold cranking amps etc etc etc

My US BMW tech friend is going to be writing me a test procedure to follow, speaks later txs

[nazali]

wondering, if I put my meter on cables on the jump points and put it in such a way it is on the bonnet when it is closed, close up and lock/alarm car, I can check it, without opening car at all ? 15mins after shut down ? hoping to get the car in the garage, so I could keep it in on the bonnet even if wet outside.
I really want to test the car charging in the garage overnight, nice and dry

Originally Posted by aerobod

Yes, I agree, battery needs to be disconnected for a true rest state measurement and to rule out parasitic draw issues where the car isn't going into a low-drain mode (that should happen 15 mins or so after shutdown).

Parasisitic draw should be less than 100mA if the car is in the low-drain mode. As I mentioned earlier, my car was just recently dormant for 600 hours with no adverse effects or need for being on a battery maintainer, with I think a 90Ah battery and likely less than 50% charge loss, that would be 75mA or less parasistic load.

[aerobod]

Originally Posted by nazali

wondering, if I put my meter on cables on the jump points and put it in such a way it is on the bonnet when it is closed, close up and lock/alarm car, I can check it, without opening car at all ? 15mins after shut down ? hoping to get the car in the garage, so I could keep it in on the bonnet even if wet outside.
I really want to test the car charging in the garage overnight, nice and dry

You would only be able to measure voltage by doing that. There are 2 ways to measure the parasitic draw current - use a conventional meter that has a fused current draw (typically 10A), disconnect the negative battery terminal and place the meter in series with the terminal and negative post on the battery, then close the trunk with the meter outside, do the locking and watch the display, there is a risk that the initial current draw could exceed the fuse rating on the meter and blow the fuse. The other easier method would be to use a Clamp meter where current can be measured by putting the probe around the ground lead at the battery terminal (can also use the positive lead, but it becomes more complicated with more than one wire to the terminal),

[nazali]

pls see the screengrabs from today.
some testing
and some questions

txs

[nazali]

1> last night this am ctek would not show full charge
2> battery discharge while stopped but car started
3> drove 1km got gas, car started, drove 6 km shops car started, drove home 6km car started, all 3 times battery charge error
4> got home, lifted bonnet DVM showed 12.45v (and at the battery) put charger on, (while working on car) charger showed 50% charge (12v 6A trickle) went up pretty quickly to 75 then 100
5> Traced and pulled dashcam cable, as suspected no issues, earth was on bodywork
6> Got out Ista kept charger on, SEE screengrabs
Ista shows a DIFFERENT millage than dash, 3442 (or similar and IT HAS shown correct in the past)
Didn't clear error's
Went into DME module, shows battery voltage 10volts
Went into 5 day and others, (see results)

7> when finished, disconnected ista DVM showed 10.45 volts, BUT car started
8> put top down to check the drains all ok
9> pulled the covers where the brake fluid is and the battery jump cable
10> inspected the cables as the black windings are not good, all seemed good, sprayed wires with wd40 and the jump terminals theres like some terminals next to hit
hit it up with some dilectric grease, both just in case, it's water penetration
11> Was going to try a windscreen rain test with the DVM to see if I could reproduce the dvm deying when it rained, but battery was 10volts
12> Checked battery again (physically and fusebox) also fusebox under bonnet all seems good)

The car looks like it's charging quickly enough and starting, but any loads, is bringing it down, for example ista, that's never happened before.

[nazali]

note worthy notes,

* while on ista, DME shows 10v, whilst on trickle charger
* Battery has now been discharged at least 4-5 maybe 6 times
* Standby current is showing as fine !

My BMW tech has suggested the below

[nazali]

I’d say drive it as usual. Hook up DMM while the car is running and see what’s your voltage at the jump start posts under the hood. You should be 14.2 up to around 14.8 or so.
While car is running 14.26 on high rev's 14.69

Next park it like you normally would. Do not hook up the battery charger but instead pop the hood and hook up the DVOM ( DMM/multimeter ) to the jump posts under the hood.
What’s your voltage at this point? It should be pretty high just after turning off the car, probably around 13V. actually I did this, this morning, when I got home after my drives I checked this first it was 12.45 volts


<at moment car is on charge> as Ista took voltage down to 10 volts

If you lock it then go ahead or if you normally leave it unlocked then do that. We’re going to simulate however you normally leave the car.
Leave the DMM connected and either close the hood so it doesn’t cut the DMM wires by hanging them out near the headlight OR leave the hood open. The car will eventually ignore the open hood and go to sleep as normal. Check the car after 2 hours but don’t open doors or wake the car up.
If the multimeter shuts off just switch it off and on again. What’s your voltage at this point?
Let the car sit for 8-10 hours and again check it. What’s your voltage? Let it sit for a full 24 hours. What’s your voltage?

What I can do on Monday is this.
Car is on charge overnight (sunday, today)
drive to work, drive home, 4pm, put DVM on leave hood open, probably in the garage,
check at 6pm (2 hours), not waking up car
12pm (8 hours) go into garage and check voltage
when you say full 24 hours from 4pm, ? if so that is 4pm on Wednesaday
I'd have to get a uber to work on tuesday

[nazali]

see below,
Day 2 was Friday, Friday rainstorm, car got to work fine, wouldnt start

It's RAIN related, but is it water related ? is it the RAINSENSOR waking the car up ?

"inside mirror under voltage detected, error "
"exterior mirror undervoltage"

not sure at the moment,

"Holy crap! How can your charge level go from 93% down to 25% in one day??? Did they actually do a draw test on the car? Frequent wake ups are not considered a closed circuit current draw and won’t show up BUT it should tell you that “frequent wakeups” are the cause of the flat battery in energy diag under causes."

[XutvJet]

Get a new battery.

[jzeiler4]

Originally Posted by nazali

see below,

"Holy crap! How can your charge level go from 93% down to 25% in one day???

That right there tells me you just need to get a new battery and be done with it.

[nazali]

battery , new battery was installed by dealer at 211km's I have taken it up to 3000km,
new battery is only 4 months old.... suspected dashcam killed battery, battery is damaged,

IF something is taking the battery down then what, I'm back to square one.

today: after morning charge, car got me to work, died after 8 hours, jumped it, drove 12kms, stopped started, drove 10km, stopped started, drove 1km. got home

put a extension lead so I could close hood. after drive, volts was around 13.xx going down. down to around 12.3x, closed bonnet, locked car.

Checked voltage, started to go up and stopped at 12,65volts. going to do a check in 2 hours time, (6pm local, now 7:32pm), then at 6hours (midnight) then leaving car on drive 24 hours (taking an uber to work) and at 6pm tommorow checking again.

[nazali]

after 2 hours 12.84 volts

[pikcachu]

Originally Posted by nazali

battery , new battery was installed by dealer at 211km's I have taken it up to 3000km,
new battery is only 4 months old.... suspected dashcam killed battery, battery is damaged,

IF something is taking the battery down then what, I'm back to square one.

today: after morning charge, car got me to work, died after 8 hours, jumped it, drove 12kms, stopped started, drove 10km, stopped started, drove 1km. got home

put a extension lead so I could close hood. after drive, volts was around 13.xx going down. down to around 12.3x, closed bonnet, locked car.

Checked voltage, started to go up and stopped at 12,65volts. going to do a check in 2 hours time, (6pm local, now 7:32pm), then at 6hours (midnight) then leaving car on drive 24 hours (taking an uber to work) and at 6pm tommorow checking again.

why did they replace the battery at 211km ?

[nazali]

This is what happened and what I suspect (also after talking to my tech)
car was a 2019- prod, dealer had in in service in 2020, I bought it in 2021 with 211km's, suspected was just demo'd with minimal millage. Just sat and shuffled.

When I went to look at the car, I saw a battery low message, can't remember exactly what, when I agreed to buy it, they said they will make sure everything is good, sales guy said, that they just straight swapped out the battery.

My tech said chances are it discharged through non-use, so damaged it.

From July to mid-September (before the battery discharge) everything was good, not a problem. So a good 3.5 months. I did multiple minor shuffles plus now I have a full time commute, whereas before I didn't

Car fax was clean, it had a BMW waranteed service (oil change).

Originally Posted by pikcachu

why did they replace the battery at 211km ?

[nazali]

voltage at midnight, 12.84, voltage overnight 12.81 (12 hours after the car was parked up)

[jzeiler4]

Those sound better BUT if the new battery was pulled down to well below 11 volts it was likely damaged. Even a new one cannot recover fully from a complete discharge.

[nazali]

I think I may have found the problem, I've been bitten by wrongly diagnosing, so I'm not going to say, just test out my pet theory over the next few days

@jzeiler, yes your right, but if I'm right, I don't mind replacing the battery, if I found the problem, the sitting over night with discharge thing I can live with the dying no,

I'm, speaking in riddles and don't wanna, will update when I get home with the battery voltage, so a total of 24 hours sitting on the drive locked

txs again

[nazali]

so update
****************
So my pet theory was not exact but did help.

Last night battery showed 12.7volts, but on started the car it died, battery went down to 9.xx volts
jumped no problem started.

Now here is what is happening

(after jump)
start car 14.xx volts
switch of car, drops to around 12.65volts and stablises stays there,
lights go off hear relays clicking
open car door (either one) and close (which in essence wakes car up)
voltage drops to 9.xx

Tried some various tests, boosted car at least 5 times and consistant
Had car on charge and started this morning

So I spoke with my BMW tech and it's the battery that's damaged, over 24 hours there is no leakage
and stays stable at 12.8xx

So regarding battery changing (don't wanna at the moment get into warantee discussion etc,
but I've decided to bit the bullet and change it out asap on my own

SO...What's involved in replacing the battery,

So I had done my 1'er and I do have ista and have looked it up in newtis
I'm getting a official BMW battery on Ista it does show to scan the QR code but I don't have that ability
is that aproblem ? also BMW replacement has it as a 90ah battery when it's a 92, my contact said thats ok

I'm a bit worried about the IBS connections, there's, newtis makes it look like not putting any strain etc, I'm also worried about sparking when reconnecting the negative

Any tips appreciated

[albertw]

There's some advice in this article you might find useful, particularly at the end about keeping the system powered while you change the battery.

https://driving.ca/column/corner-wre...you-be-missing

[nazali]

txs albert

so picked up battery from BMW today,checkd the voltage, 12.87v, put it on trickle charge using the ctek.

started from scratch and took ages to get to float (about 4 hours) voltage sitting around 13.53v - funny enough the description for float says "1 day. Charging cycle restarts when voltage drops" and also The battery voltage is maintained at it's maximum level by charging it at a constant voltage

Assuming the accuracy of my meter, 12.87 put's it around 95% ish

I'll likely only keep it on overnight

[nazali]

OK so while I'm waiting for tommorow, I decided to pull some stats of both batteries, the one I charged up and the one still in the car (after a boost as I had to move it)

ok so here's the stats on the cars:

1> NEW BATTERY after being on charge 12 hours this is what it says

V=13.20 / CCA 949 / SOC 100% / 2.68mOhms / SOH 100%

2> IN the car from the jump points


v=12.81 / BAD CCA 235 / SOC 97% 10.78mOhms / SOH 27%

The CCA is 850 new one shows 949 not sure why, not complainging ? look at the internal resistance,
the voltage is garbage the batteries shot.

maybe I should have way back, just did a tried and tested, pull the terminals off and check the battery, taken that to BMW, but not sure if that would have helped

anyway, swapping the batteries tomorrow

[nazali]

So battery replacement went without a hitch.

cleared the codes and registered it, also noticed that while using ista it wasn't warning me of shutting down the idrive, after all my tests and everything, car sitting happily at 12.60v, locked car up and going back to it after it's slept open doors etc and check voltages again.

I used the solar, it gave totally incorrect readings at the jump terminals (said the battery was bad LOL)

So on the battery I again did a battery check, cranking check, alternator test, alternator load test and alternator ripple test, all good.

Ista showed no closed current or anything above 80ma draws. cleared codes
so now ver the next few days will monitor it all