Parasitic draw

I know this has been asked before but most of the websites and videos I’m watching are over my head.

I just replaced my battery and it died after two weeks. Battery checked out good at O’Reillys when I went back this afternoon. I got out my multimeter and the battery is currently a 12.5, when the car is on w/o a load it’s in the high 13s and with radio, lights and light bar it’s 13. So, I think my alternator is good enough.

I tried to do a parasitic draw test, but I don’t think I’m doing it right. I disconnected my negative terminal and set up the multimeter as pictured I then touched the negative lead to one end and the terminal to the other of my multimeter. On the attached settings the drain was .5 which I think is acceptable if I set up the meter right.

If so why is my battery dying so fast?

 

Assuming you have cleaned everything up and replaced the cables (making sure they are routed correctly) try disconnecting the negative for a few days and see what happens to the battery. If it remains good, then you have something drawing, not unusual on newer vehicles, or a short somewhere. The short could even be intermittent happening only when you are driving.

 

Any aftermarket wiring done? Auxiliary lights? Stereo changes?

 

My wife's Highlander has a parasitic draw that I'm 99% sure is the Autostart but I haven't disconnected it yet. If she drives it every day, it's fine but if it sits all weekend, it'll be dead Monday morning.

 

1/2 amp of parasitic draw sounds high to me. Although I've never tested mine. Maybe someone can chime in about the normal parasitic draw on the 3rd Gen.

With your meter connected as you did, pull fuses one at a time and see what is drawing that much current. Curious as to what is doing that.

 

I have three aftermarket items, a Caliraised Lightbar, N2 Designs Remote Start w/ module, and the Camper Shell. I know my lights aren't on in the camper shell and I pulled the fuse on my light bar and nothing. I am not sure how to check the Remote Start, but I have had that for over a year. I haven't driven my car much since COVID19, so I could have been masking the problem.

Did I actually do the draw test correctly? Is .5 acceptable on those settings?

 

I believe you did....

Disconnect the neg from the battery, put the black meter lead on the neg cable and the red meter lead on the neg battery terminal.

I did a simple calculation with some generic battery assumptions and with that draw of 0.5 amps, the battery would be dead in 25 days, if you didn't drive it.

 

Definitely way high. I think bmw spec for current draw is >40milliamps but I haven’t looked up the spec in awhile. I know it’s definitely less than 100milliamps

 

It’s likely that remote start disconnect it with your meter reading the current draw and will probably go down

 

.5 seems high to me as well. Like n6vmo said, with the multimeter connected the same way start pulling fuses and relays one at a time, wait 5 or 10 seconds and see if the draw tapers off. That's the best way to narrow it down to one or two circuits. Also I would double check your alternator, with my truck running and all my lights on i get 14.2 volts.

 

Important note on your testing strategy make sure all door latches are closed even with the doors open which you can do with a screw driver and lock the vehicle so that the control modules can go to sleep or your readings won’t be valid

 

I've done this on other cars, the draw can stay high for a good 10 minutes before it settles down.

At .5 amps, you're drawing 12 amps a day. Battery could be dead in short as 4 days. Would want to run your engine at least once a day.

 

Typical amp-hours for a standard battery is around 45 amp-hrs, with a 1/2 amp draw ya got less than 90 hours till she’s totally dead. (Don’t use cold cranking amps to calculate that’s just an instantaneous crank rating, nothing to do with capacity).
Read every post in this thread linked below and you’ll have your answers, also another post said close your doors and hood when testing I have no comment regarding that but if you have a key fob take it far away and wait a couple hours to see if the drain current drops like it has for others.....
https://www.tacomaworld.com/threads/ma-draw-w-truck-turned-off.644085/#post-22305363

 

I got it, so i was doing a couple of things wrong. I appreciate all the suggestions.

I disconnected my battery and put my multimeter in between the terminal and negative cable. I don't have small enough clamps so I was reconnecting every time. Biggest thing was I was not waiting for the volts to drop. Its almost 30 seconds to get back to baseline. Once I figured that out, I pulled my GPS Remote Start and waited 30 seconds it dropped down to .04 Amps or 40 ma. The Remote start was using 250 ma of power at rest. When I tested this the first time I was waiting for about 15 seconds and it would sit at 50. I am guessing there are some initial start up modules that draw power that need to calm down before an accurate reading is produced.

 

You got it. If you didn’t have something on or a door not fully closed, you may have a faulty new battery. You didn’t mean two weeks without driving it did you? That can do it too lol

 

Looks like your meter is set to AC amps, not DC.

 

Anything over .06 amp is a current draw

 

Amps is amps. There is no ac/dc amps

 

That really depends on the meter.
https://www.kele.com/content/blog/using-a-multimeter-series-current-measuring-basics

 

I think I only drove it once or twice since I got the new battery, I have been working from home. Now I probably need a battery maintainer or a portable jumper... its a pain in the neck to use my wifes car.