Here is a simple write-up for troubleshooting battery drain issues on your Volvo. Recently I went on vacation, when I returned my battery was dead. I thought this might be a good time to document how to track down battery drain issues with some pictures. Keep in mind I did this with no clue as to what was causing this drain.

Step One:

Get your battery charged back up.

First of all my battery was fairly new so I really did not suspect it. If I had I would charge the battery and then do a load test. I have a Snap-on load tester to do this but if you dont, take your car to Kragen or Autozone and they can do it for you.


Step Two:

Check for current draw.

Your going to need a multimeter that can read current draw. Basically your going to introduce your meter between your positive -or- negative battery post. This will cause any current the car is using to pass through your meter. ***a word of caution here. Do not attept to start your car with your meter in place. Most meters can only handle 10 amps or less, your starter uses hundreds.

Meter in Place

On a normal vehicle there are several electrical components that need voltage all the time. You will have a current draw regardless of anything being on. For example, your radio memory or alarm system. The normal current draw should be around .01-.07 amps. If you are seeing higher than this you could lose your battery if your car sits for several days.

Here is what my draw was after recharging my battery


So I have a current draw. In this case I was pulling just shy of 1 amp or 8 tenths of one amp. Regardless the result of this is a dead battery after a few days.


Step Three:

Find the circuit that the draw is coming from

To find the culprit begin pulling fuses from your fuse box. Pull them one at a time checking the meter then put the fuse back and move to the next. This will narrow down where the draw is coming from.



Eventually I found the fuse that was causing the draw. When pulled the draw went down to .02 amps which is right where I want it to be. I checked the fuse list to see what that fuse ran. It said dome light, courtesy light, etc. So I put the fuse back in and started looking. Eventually I found the rear tailgate had not been closed completely leaving the rear lamp on. We left for vacation during the day and returned during the day and did not see the lamp in the back.

With the tailgate now closed I checked the meter and to my surprise there was still a current draw.



So I went through the process again. Again it was the same fuse. I checked the lights again and none were on. What else would light I thought. Visors and glovebox came to mind so I checked. Turns out the glove box was also not closed enough to turn off the light within the glovebox.

With that corrected the draw was now down to .02 amps which is right where we want it.


Although this was a simple fix the principle behind these troubleshooting steps remains the same for more complex drain issues. The idea behind finding the culprits is to eliminate them from the system. For example if a diode pack goes out in your alternator you can end up with a current draw. Disconnect the Alternators main power and trigger lines then check your meter.

Hope this helps. Class dismissed.

 

Nice, thanks

 

This is an excellent writeup Boxpin!! And long overdue as a sticky on this site; wish i had a nickel for every time somebody asked the question that this post answers!

Thanks for saving me the time to write it! Only thing we need to add is a good how-to on charging system diagnosis; you alluded to part of it when you mentioned how a shorted diode pack in your alt can also cause a battery draw.

Good Job!!

 

Hopefully it will become a sticky. Its a good subject.

I can create a troubleshooting guide for charging but I need a bad alternator, which I dont have.

 

Nice.

I made it a sticky.

 

great! thanks very much needed.

 

Boxpin, can an AC/DC multitester substitute for a load tester?

 

No way, no how.
A load tester needs to act like the starter motor in that it has to draw a couple hundred amps. Think of it as a huge light bulb. It draws all this power into itself and then depending on the amount it draws and the rating of the battery you need to do this load test for "X" seconds and monitor the voltage.
The battery needs to be strong enough to crank the engine while maintaining a minimum of 9.6 volts. Below this the battery may crank the engine but there isn't enough voltage for the ignition to fire the plugs.
When in doubt either take the whole car or the battery to a parts store and have them use the handheld tester on your car or toss just the battery into their charger. The battery needs to be fully charged before testing and their testers will do exactly that. They all do these things for free.

 

For probably one second then it will pop the internal fuse or burn up your meter. The real answer is no. You need a load tester to test a load. I think your using the term 'load tester' differently than what we see it as. Yes, most meters can check for current draw but are limited to about a max of 10 amps. It will say it on the meter and most meters have fuses internally to protect them. When you buy a battery they are rated in CCAs or Cold Cranking Amps which are way beyond the capabilities of a multimeter. As an example, you could not test a starter current draw with a multimeter it pulls way to many amps and would damage your meter.

This is a load tester:
Battery Load Tester - 100 Amp, 6v/12v

 

Thanks Box and Kiss,

I don't want an expensive one like the FLUKE Box pin had in the pictures but something to turn to once in a while. Will try out the site you gave.

 

Here is a link I found about battery info:
How long does it take for your engine to charge your battery? - Yahoo! Answers

 

I don't want to rain on the parade...but I have a 94, 95, and a 96 850 Glt, they draw .025 amps, charge at 14 plus at idle with the lights on, but all go dead in a few days of non-use.
I've been a mechanic for 50 years. Batteries, alternators, engine swaps, my only solution is to unbolt the battery of the cars I'm not driving, and keep a charger nearby.

 

Thanks much for that, Lilbobby. Now another question: when I lock the car, everything goes off. Does that turn off some lights inside that may be on that I'm not aware of, such as the glove compartment light? (That's no longer a problem now since Volvo Forums solved that for me) So, presumably, when locked, there shouldn't be a drain? Or does it still drain?

 

Something you said here doesn't add up...? Off by decimal point maybe?

0.25A draw will pull a good battery down in few days, but not 0.025A. The latter is w/in the normal range and a charged battery should last for weeks w/o running the engine.

This normal parasitic current draw (< 50 mA typical; certainly < 100 mA) is needed to preserve volatile memory data in the control modules. That's why pulling the battery will reset everything to default settings.

 

Seconding gdogs statement.... .025 amps is perfectly normal.