Battery Drain?

[Purplecty]

Originally Posted by 80stech

You are not doing that test and you aren't using the listed procedure or equipment to do it so why would you even look at that chart ??

Yeah you are correct! I was just going based off the elapsed time and the voltage I am seeing on the cluster which isn't helping much...

[Purplecty]

Test9 is battery voltage

[c-bass]

Originally Posted by Purplecty

Test9 is battery voltage

Even after a couple days of sitting Swampy is over 12V and I know there's something not right with her.

I think your battery should definitely be holding over 12V.

[StephenVA]

For the 27th time, here are the procedures for determining battery state, charging state, and finding a battery drain. Guys it NOT rocket science...

Starting & charging systems testing techniques
Without spending too much time on starting & charging systems testing techniques, here are a few quick tests to determine a battery issue, a charging system issue, or a primary wiring issue.

Tools required: Digital Volt Meter (DVM), battery terminal cleaning tool, and 8mm, 10 mm sockets and ratchet with extensions.

You need to read battery voltage before starting any test on an electrical system as it will influence the results of Starting, Charging, and electrical tests of any kind. (Note: battery must be fully charged, see chart)

Step one: Get out a digital volt meter, Read battery voltage (Key off). Read voltage (Key on) at the following points Battery, under hood jump point, and at the alternator. You only need to determine if you have 12 volts at the alternator with the key on (BIG FAT WIRE). A simple handheld digital wave form tester will get you in the ball park when it comes to batteries. (Further discussion on these testers is for another engineering forum). I have a handheld Chrysler tester that was put out in 1980 to help low skilled techs determine charging system functionality. It has three lights: Battery voltage good (12.6v), Alternator good (13.5v), Fault (anything else). That’s it. I had this in my bag of tricks when I sold auto testing equipment.
Step Two: You need to read the voltage at the BATTERY at idle, 1500, and 2500 RPM to determine voltage regulator function. Better still would be a Volt Amp tester (VAT-40 Image below) to induce a correct AMP load to read actual AMP/Volt output from the alternator and battery, as that is the only true testing method. Having a DVM that has min/max capability will make your testing easy.
Step Three: Remove and clean each and every ground in the trunk, jump point, and at the frame rail for the block (bad grounds = lots of electrical issues). Clean the starter/alternator cable connection under the car, just under the dead pedal.
Step Four: Failure to get correct output on running test means DEAD alternator (volt regulator, brushes, windings, etc.) Remove and bench test the unit or drag it to your local auto parts store for a second opinion (which will be worth exactly what you pay for it....)

Base line numbers
Battery Voltage should be 12.6+V (Key off) See chart below.
Battery voltage should be 13.5v - 14.5v on running tests (note large fluctuations at running RPMs is a SURE sign that the Volt Regulator is not doing its job. Smack with rubber hammer and retest. Rebuilt units have large variance of quality control from good 85% of the time to approx 50/50%.

NOTE: The exact charging voltage will vary according to the battery's state of charge, the load on the vehicle's electrical system, and temperature. The lower the temperature the higher the charging voltage, and the higher the temperature the lower the charging voltage. The "normal" charging voltage on a typical application might be 13.8 to 14.3 volts at 77 degrees F. But at 20 degrees F. below zero, the charging voltage might be 14.9 to 15.3 volts. On a hot engine on a hot day, the normal charging voltage might drop to 13.5 to 14.3 volts.

Note 2: TIS specifies alternator voltage as 14.3 +/-0.1 V. But that is measured at the alternator output post. The values seen using the cluster will be 0.5 V or more below the alternator voltage output.

Batteries surface charge.

What the heck is a surface charge?
When testing wet cell auto batteries, some will show a 12.xx Volt result, but as soon as a 100-150 amp load is applied, they drop straight down to 9.8V or lower. Classic example of a collapsed cell wall (internal short). This is why too many DIY and techs get stumped when they pull out a meter and say "It shows 12.xxV so it must be good”. NOPE, batteries are tested for voltage holds and AMP draw capacity as well as the ability to recover and recharge over and over again. Batteries are nothing more than an energy storage device. Their usage back in the 1920's allowed for a "self-starter" option, Now days we take it for granted. In the future we will use the engine ignition system to fire off a cyl while disabling all other cyls (opening the exhaust valves) allowing for a start that requires no electrical/mechanical starter. A topic for a SAE publication but an interesting future none the less. The challenge is for the average DIY to approx the load test with KEY OFF.

Solution: Set a volt meter to DC volts 0-25 scale or auto ranging if so equipped. Read and record voltage
Turn on everything in the car for 15 seconds:
Headlamps to high beam
Heater blower motor to high w/ A/C on
Seat Heaters
Rear Defroster (and rear seat blower if so equipped)
Interior lights
Radio
Fog lamps
Cigar lighter
etc, etc, etc

Read voltage after testing. You should see a drop off of .5-1.5Volts during the test and a slow rise back to 12.5V+ on a completely healthy and fully charged battery in 30sec to 1 min.
A battery that is DEAD, will show 9.8V or less and never recover until charged.

Battery Registration: There is NO battery registration required for proper operations in a E39 or E53 application.

Alternator testing tips
To quote another poster...

How to load the alternator at engine idle for alternator output tests:

Note: Alternator output should be tested with the engine idling under the following four loads after at least 15 seconds of idling (for the alternator to ramp up):
Turn the high beams on
And, turn the rear defroster on
And, turn the fan on (full force, I guess)
And, turn the wipers on (to the regular setting, I guess)

These loads should be left on while the alternator output tests are being performed.

Once access to the alternator is gained (access for the I6 is vastly easier than the V8):

• Check the voltage from the alternator #30 post and ground
o It should be the same as the battery voltage
• Now disconnect the harness connector to the alternator:
• Check voltage from terminal 15 and ground (field voltage)
o It should be the same as the battery voltage

More info: Another way to check alternator output is with an oscilloscope. Observing the "ripple voltage" pattern will tell you at a glance whether or not all the alternator windings are functioning. A "good" pattern should look like the top of a picket fence. If any of the humps are missing, it means one or more of the windings is grounded or open, or there's a bad diode. Most battery/charging system testers also have a test function that can detect bad diodes.
Ripple testing with a DVM:

ANOTHER QUICK CHECK FOR BOSCH ALTERNATORS

One way to check the integrity of the alternator and diodes on Bosch alternators is to check the voltage readings at the D+ (blue wire) terminal and B+ terminal. The voltage reading should be the same at both terminals. A difference of more than one volt would indicate faulty diodes and the need to replace the alternator.
Tips link: https://www.diyauto.com/manufacturer...ion-by-bluebee

Volt Drop Testing (Image below) will show you issues with grounds and wiring problems. Read the text and test a few spots to determine if your car has clean connections.
https://www.engine-light-help.com/voltage-drop.html

Are you having other electrical issues? Alternative issues: Ign Key switch failure, wiring junction box rusted (see water leaks under passenger seat(E39), Water standing in trunk under the battery (E53) and the normal wiring broken connectors, grounds), etc....

Tip Sites for more info:
https://www.aa1car.com/library/2002/cm10220.htm
https://www.bimmerfest.com/forums/sh...d.php?t=510579 (Everything you wanted to know about BMW starting and charging systems for DIY)


Helpful?
Attached Thumbnails

[StephenVA]

When your car battery goes dead overnight, usually either the battery is at the end of its life span, or you left something on, such as a light. Occasionally something is drawing power that's not of your doing. This is a parasitic draw, and it can cause the same result as leaving the headlights on: a dead battery in the morning.

1. Remove the negative side battery cable from the negative battery terminal.
2. Connect the black wire to the com input on the multimeter and the red wire to the 10A or 20A input on the multimeter. The meter needs to be able to read at least a 2 or 3 amps for this test to work. Connecting the red wire to the mA input on the multimeter won't work and could damage the meter.
3. Attach a multimeter (set the dial on the multimeter to measure Amps as per multimeter instructions) between the negative cable and the negative battery post. Wait a few seconds to several minutes for the car to go into sleep mode - i.e. when you make the contact with the ammeter, the cars computer systems "wake up". After a bit of time they will go back to "sleep".
4. If the ammeter is reading over 25-50 milliamps, something is using too much battery power.
5. Go to the fuse panel(s) and remove fuses, one at a time. Pull the main fuses (higher amp ratings) last. Perform the same steps for relays found in the fuse panel. Sometimes relay contacts can fail to release causing a drain. Be sure to observe the ammeter after pulling each fuse or relay.
6. Watch for the ammeter to drop to acceptable drain. The fuse that reduces the drain is the draw. Consult the owners' manual or service manual to find what circuits are on that fuse.
7. Check each device (circuit) on that fuse. Stop each lamp, heater, etc. to find the drain.
8. Repeat steps 1 & 2 to test your repair. The ammeter will tell you the exact numbers.


Typical Charging system demands
Equipment Electrical Draw
Rear Window Defroster 25 amps
High Blower 20 amps
Headlamps (Low beam) 15 amps
Windshield Wipers 6 amps
Ignition 6 amps
Brake Lights 5 amps
TOTAL 77 amps

A proper charging system and battery is required before any electrical tests are performed.

Anytime battery voltage drops below 9.6v all kinds of random faults pop up. As these cars get older and especially on newer cars, the demand on battery capacity only gets more extreme. Average life span of a battery is 3 years. If you use a "battery tender/trickle charger" religiously, like every time a BMW is parked for more than 24 hours, you can get 5-8 years out of them!

A few quick tests before you pull out/off any battery/alternator to determine battery/charging system failure. At this age and mileage, the Alt brushes wear out and give an intermittent to no charge swings making lots of issues as mentioned.
Step 1. Remove and clean the posts at the battery and neg cable grounds. (Your vehicle has neg cables grounds in more places than the trunk. See frame rails grounds for example.) Remove and clean the positive jump point under the hood at the driver's side firewall. Remove and Clean the positive cable at the alternator (note: do this step while you have the battery disconnected)
Test one: With a volt meter on the battery posts do the following tests:
- Key off, read battery voltage
- Idle read voltage
- 1500 RPMs hold for 1 min and record highest and lowest voltage
- 2500 RPMs see above
Note: You are looking for ANY fluctuation that would indicate charge/no charge, Example volts read 13.7 then drop to 12.3 then up again. It will be normal to see 13.5 to 14.1 for example while running the tests. To make the test simple turn on a few high load accessories (headlamps, heater blower, seats, rear defroster)

Last test
Engine off, turn on headlamps on (key needs to be in Acc position 1) and turn on seat heater, blower on high and rear defroster) for 15 secs or so.

Read battery voltage. If voltage is below 12.6, charge battery. If you have a less than a 15 amp charger, charge overnight and reread battery voltage. When cell walls collapse in a battery, the battery will hold only a surface charge then croak when you apply a load over 100 amps for 15 secs. Hence why you need a carbon pile tester to truly test a wet cell battery. Yes there are capacitor based testers that will get you into the 85% range of accuracy for those who follow the tester world.

Note: If your battery has lots of white crud all around the posts, save yourself lots of pain and throw it away before you waste any more efforts...

Report back!

What you are doing here is to see if the battery and charging system are working properly without the proper tools like a carbon pile load tester. This type of tester allows you to properly load a battery and then the charging system to read true out puts rather than SWAG (scientific wild ass guesses) from internet postings. The tests I recommended will take a few mins and it will provide a lot better result than the local parts store's happy meter.

Typical Charging system demands
Equipment Electrical Draw
Rear Window Defroster 25 amps
High Blower 20 amps
Headlamps (Low beam) 15 amps
Windshield Wipers 6 amps
Ignition 6 amps
Brake Lights 5 amps
TOTAL 77 amps


See chart below for battery health results.


Helpful?

[StephenVA]

and even more!
BMW Vehicle Parasitic Draw Testing
When your car battery goes dead overnight, usually either the battery is at the end of its life span, or you left something on, such as a light. Occasionally something is drawing power that's not of your doing. This is a parasitic draw, and it can cause the same result as leaving the headlights on: a dead battery in the morning.

1. Remove the negative side battery cable from the negative battery terminal.
2. Connect the black wire to the com input on the multimeter and the red wire to the 10A or 20A input on the multimeter. The meter needs to be able to read at least a 2 or 3 amps for this test to work. Connecting the red wire to the mA input on the multimeter won't work and could damage the meter.
3. Attach a multimeter (set the dial on the multimeter to measure Amps as per multimeter’s instructions) between the negative cable and the negative battery post. Wait a few seconds to several minutes for the car to go into sleep mode - i.e. when you make the contact with the ammeter, the cars computer systems "wake up". After a bit of time they will go back to "sleep".
4. If the ammeter is reading over 25-50 milliamps, something is using too much battery power.
5. Go to the fuse panel(s) and remove fuses, one at a time. Pull the main fuses (higher amp ratings) last. Perform the same steps for relays found in the fuse panel. Sometimes relay contacts can fail to release causing a drain. Be sure to observe the ammeter after pulling each fuse or relay.
6. Watch for the ammeter to drop to acceptable drain. The fuse that reduces the drain is the draw. Consult the owners' manual or service manual to find what circuits are on that fuse.
7. Check each device (circuit) on that fuse. Stop each lamp, heater, etc. to find the drain.
8. Repeat steps 1 & 2 to test your repair. The ammeter will tell you the exact numbers.


BMW Battery Draw Testing
If your Shifter light is on, the car is definitely staying awake.
Your Battery will go down within days. If the light is not on you can have a parasitic draw, while the car is in sleep mode. The only difference, is the second draw is from a module which can’t wake the system (not mission critical), and it will take a lot longer to discharge the battery.
Shifter light NOT on: (battery fully charged)
Find the ground cable on the battery, but do not disconnect. (the cable end connected to the body not the battery, is easier to handle.)
Connect the Positive lead from the “Fluke” to the body of the car (good ground)
Connect the Negative lead to the (brown) ground cable (you can puncture it)
Make sure it’s easy to disconnect the (brown) cable from the body, but don’t take it off yet.
Open the glove box and remove and disable the switch so the light will not turn on, locate the fuse box.
Start the car and run at idle, turn EVERYTHING on, and activate all the components (sunroof, windows, a/c, lights …..) run 5 min.
turn the car off and remove the key. Open all doors and trunk, and with a screw driver,
close the door locks so the system thinks all doors and the trunk is closed.
Now lock the vehicle with the remote.
The “Fluke” must be set up to “A” not “mA” otherwise you will blow the
fuse in the meter. Remove the nut from the ground cable and remove the cable from the stud. You meter will indicate around (300mA).
Let the car go to sleep. (16 min) minimum, if this is not happening start over.
After the sleep mode is on the draw should not be more then 50mA, if it’s more go to the glove box and start pulling fuses one by one and check the draw after each one, but do NOT re-install the fuse. Pull the fuse and leave it out
There are some fuses under the right cover in the trunk. If you pull a fuse and car wakes up start over (next time ignore this fuse). If you pull a fuse and the draw drops to around 50mA, read the label on the fuse, you will know which circuit is faulty.
Relay locked on - test
Take out your infrared temp gun and measure each relay. The one that is hotter is "on". Simple!

[oldskewel]

Electrical things can be fairly complicated. So what I do and suggest to others is to figure things out with your car(s) BEFORE anything is wrong. For the E53, that would mean:

See if the orange LED by the shifter goes out after 16 minutes when the car goes to sleep. Some swear it must. I know mine does not, and my car does go to sleep (from monitoring voltage on a sleep-controlled circuit), and I have no drain issues. This test requires you to look through the driver's window before unlocking the door one morning.

If that was not too hard , then ...
Turn the key to ON, if you have the high cluster, see what Test9 says. This number is typically 0.3-0.5 Volts less than at the battery / jump port / alternator. I believe it is lower since it is a regulated voltage used by the more advanced electronics, so is lower than the raw, unregulated system voltage.

Put a cig-lighter voltage gauge in the outlet, see what voltage that says. (for bonus points, you can calibrate that gauge vs. your voltmeter (or two, if there is any doubt in that accuracy).

Use a voltmeter to measure voltage at the engine bay jump port. And at the battery some time when it is convenient. Those two should be identical when the engine is not running.

^^^ those measurements tell you something about your battery voltage and how your car's electrical system responds to that voltage.

Then you can run the engine and check all those voltages again. That will let you see what changes when your perfectly good alternator is running.

You can then stop the engine and repeat the ignition ON, engine stopped tests from before, to see what a freshly partially charged battery measures, and how quickly it drops to those original numbers.

If you do all that when the car has no problems, you will know that baseline for comparison when you have doubts one day, and those numbers will be far more relevant (your car, your known good battery, your known good alternator, your climate, your driving routine) than general numbers you see on the internet.

[Purplecty]

I sat in the x5 and heard the little IHKA internal fan running with the ignition off. I confirmed the little internal IHKA fan stopped and the shifter light went off after the 16 minutes to confirm she is asleep. I think my battery is fine. I will keep an eye on it to see how low the battery voltage goes over the next few days as she has been sitting in the garage and I work from home...

[puddinboo]

Sometimes this blower resistor can cause battery issues, by keeping you blower running. If its faulty.

Originally Posted by Purplecty

I sat in the x5 and heard the little IHKA internal fan running with the ignition off. I confirmed the little internal IHKA fan stopped and the shifter light went off after the 16 minutes to confirm she is asleep. I think my battery is fine. I will keep an eye on it to see how low the battery voltage goes over the next few days as she has been sitting in the garage and I work from home...

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[puddinboo]

My orange LED by the shifter goes out within 15 min. Just a FYI

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