Dying battery

[AZ Landshaper]

Have had a slow dying battery for a month now. Could be the battery has had enough or there may be a slow draw on the battery.
Ive connected my test lamp between the neg cable and the battery and dont get illumination. Is this a legit test of a draw? For example if the draw was less than 12v would it still trigger the light?

I was thinking this had to do with wiring of a radio recently installed but I disconnected the radio and still the battery dies from 12.6v to 12.v in 48 hours. 12v will not turn my starter.

I took the battery to the auto parts joint and they did their tests and told me it tested good. Not sure how much faith I have in this.

Im going to reconnect the radio so I can drive today. Cant drive without a radio right? Correct.

Is it ok to jump to the cigarette lighter for the constant current and no 8 in the fuse panel for the key-on power? Got a better idea?

Thoughts appreciated?

Jay
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85 Weekender w/ EJ22
Previously
64, 71, 72, 73, 76, 81, 84, 85 & 87 Campmobiles and Westfalias
and a 67 bug.

[djkeev]

A decent write up.......

https://www.popularmechanics.com/cars/car-technology/a5859/how-to-stop-car-battery-drains/
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Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473

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http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537

Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[jimf909]

EDIT: the below fuse 3 is for a '90, not an '85. The cig light is #8 in an '85


The cig lighter is on fuse #3, always hot, which is the same circuit as the always hot radio circuit do that should be fine for the radio memory.

I'm not certain about #8 for key in power. I tapped the ignition switch for that.

Do you have a multi meter? That's what I use to measure current draw by putting it inline between the neg batt post and the net batt cable.

Others will be along to correct my errors.

Does this look like your fuse panel?

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- Jim

[Ahwahnee]

Do you know how old the battery is? Tucson summers take a toll.

I agree - a simple ammeter is the best test for a phantom draw - then it is quantified.

Is the 12.6 volts you mention just after charging the battery? If so you might want to turn on the headlights for a few seconds before measuring to get rid of any 'float' charge that may overstate the battery condition.

Usually the load test at a FLAPS is fairly fool proof - all the more so as they want to sell batteries - but it is not absolute proof.

[MarkWard]

Testlight between the ground and the battery is a good test. If there is a big draw, the light will be bright. A small draw will be very dull.

Another test is if you get a small arch when you attach the battery ground to the post. From memory a fully charged battery with the surface charge drawn off is 12.9 volts.

A volt ohm meter will give you a precise load amount, but many meters can handle only 2 amps max. So, you need a little caution. Based on your testlight testing, I’d say if there is a draw, it’s well under an amp which should not kill a good battery over night.
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[DanHoug]

my advice would be to go to a store and buy yourself an inexpensive multi-meter. you're just guessing with a test lamp and really need to know some hard numbers during the testing phase.

then you can start pulling fuses one at a time and narrow the problem. lastly, disconnect the alt.
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-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
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[AZ Landshaper]

Ok. Maybe a dumb Q but
I’m
Not electrically inclined on many levels.

Is this meter set to the correct setting to quantify a draw on my battery.
If so... I’ve put the meter in line w the battery negative terminal and the negative cable and pegged the meter.

As Mark suggested the draw maybe more than the meter can handle or I as I’m suggesting I may be using the wrong setting.
Anyone familiar w this style of meter and the 250a setting in regards to vanagon battery draw.

The biggest reason I’m doubting myself is the meter pegging on the top end of amperage reading and .....no change from removing fuses. Removed them all in an effort to locate a culprit.

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85 Weekender w/ EJ22
Previously
64, 71, 72, 73, 76, 81, 84, 85 & 87 Campmobiles and Westfalias
and a 67 bug.

[Abscate]

That’s right, you’ve got it.

Full scale is 250 milliAmp or 0.25 Amp

If it pegs you could have a 1-2 amp draw, more than that would probably burn the meter out or blow the fuse.

A 1-2 Amp draw will kill a weak battery overnight
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[DanHoug]

[AZ Landshaper]

Sounds like an interesting bike.

I do believe you are correct. Free HF meter. I was afraid I was gonna get that answer at the same time I want answers and will buy a better meter manana.

What about the fact that the needle never dropped while I pulled fuse after fuse? Is there something obvious I could be missing there ?
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85 Weekender w/ EJ22
Previously
64, 71, 72, 73, 76, 81, 84, 85 & 87 Campmobiles and Westfalias
and a 67 bug.

[DuncanS]

Get a hygrometer and test the battery after charging, test 1. Then remove the ground from the post and test again the next day after it's just been sitting there unconnected. If one cell tests low, then the battery is junk, test 2. If OK, reconnect the ground strap and test it again 24 hours later, If one cell is lower than the others, it is junk, test 3.

If OK, get an auto ammeter and connect it with heavy wire between the battery ground post and the disconnected ground strap. If nothing is on in the car and the key out of the ignition switch and the needle of the ammeter moves, even the tiniest bit, you have an electrical leak and need to take it to someone who is good with auto electrical issues. Electrical problems can be difficult and expensive to find and resolve. Even if you get a new battery, you will soon kill it too because of repeated total discharges. If you buy a new battery, you can use the car, but will need to disconnect the ground strap from the battery after parking it until you an get it fixed. Given your electrical skills, I doubt you could fix it yourself.

Get a decent multimeter and test the voltages just before any hygrometer test.

Battery age is very important as is the number of times it has measured 12 volts. 12.0 volts is an almost dead battery. 11.8 is completely discharged. If you see any of these numbers after test 1, 2 or 3 the battery is junk.

[Abscate]

[DuncanS]

Exactly, and probably not even fused.

[DanHoug]

[Ronzo_volvo_guy]

Jay;

Good info from others...to that, let me add the practical experience, that some audio sys power amps are notorious power consuming pigs (even when allegedly OFF!!) See: https://www.sw-em.com/Battery%20Notes.htm#high_parasitic_load_audio_amp

Another passive way to verify it was either the Batt or something draining, is to fully charge, and measure V (should be 12.6V) and disconnect in the evening, and measure V, and reconnect before starting in a day or two...V should not drop very much at all overnight (as there are absolutely NO loads on it), and if it is able to start engine, that means its capable of holding a charge...if V drops significantly, Bat can suspect...free Batt test at Pep Pills Boys or similar are typically storage and load tests, and they have said it is OK...

The active way to check for a phantom load is to measure current (meter in series) with everything OFF...Stereo memory, and Alarm system, and other incidentals should not draw over 100mA...if you are measuring more than 250mA (you said meter goes to over-range!) that is WAAAAY to much phantom load...locate this and understand how and why (if necessary post back with findings), and eliminate this!

See also: https://www.sw-em.com/Battery%20Notes.htm#overnight_battery_discharge ).
Good Hunting!

[AZ Landshaper]

[jimf909]

Hmmm, the coincidence of he radio add is suspicious. Does the radio have two power connections: one to always hot to keep the memory hot and another to key-on or key-in power? If one of those is connected to a non-fused source that may be an issue. What does the ammeter read if you disconnect the radio from power?


Edit: Nevermind.

[AZ Landshaper]

I’m not that far yet Jim but likely will be manana. I just bought a better meter. Capable of 10a readings. I got a reading of .09 when placed btw the neg terminal and the neg cable. I know now this is 90mA. Seems 50mA is normal but is 40mA difference that detrimental? I guess it might be if we have a bad cell. FYI this is a Napa battery from 2018 thats never been maintained but never had any issue either.
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Support Small Business.

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85 Weekender w/ EJ22
Previously
64, 71, 72, 73, 76, 81, 84, 85 & 87 Campmobiles and Westfalias
and a 67 bug.

[fxr]

Have you removed the big wires on the alternator yet? In trying to find a high-amp replacement alternator, two that I received via Ebay had high parasitic current draw, that would flatten my good starting battery within two days.
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Jim Crowther
1984 1.9l EJ22 Westy Wolfsburg Edition
Vespa GTS 300

[Ronzo_volvo_guy]

Jay;

A bad cell is not going to cause that measurable current draw on the Batt...only external loads tied to it!...and 90mA is still on the high side for me!... what could possibly need that much stand-by power?...I would still want to inform myself where it was going, what load was using it, and convince myself that this was not an error condition. If it was me, I'd pull all Batt power fuses one at a time, while monitoring that current...if no difference is noted when all Batt power fuses are pulled, it must obviously be an unfused load...I'd still want to know...but that's the curious engineer in me...!

A Lead-Acid Batt cell can go bad several ways, but noticeable differences while charging (one cell does not produce as many H2 bubbles, or final fully charged Voltage is less than 12.6 (which is equal to each cell's contribution of 2.1V X 6, or hydrometer Specific Gravity measurement of acid is weak for one cell, etc). A cell can be shorted by a conductive flake if Lead sulfate...that's why it is not uncommon to give a Batt like that a good whack, by dropping it from a couple of feet...this disturbs and can "fix" a short...kinda violent, but it has worked, and more than once...but that is not your issue! Find where your phantom current is going!

Good Hunting!