How much to fix a parasitic battery drain

Q: Can a parasitic drain ruin a battery?

Whats the Danger of Parasitic Drain? If a battery goes long periods without being recharged by the alternator, those tiny milliamps drawn by parasitic devices will kill it. Even normal parasitic drain, also known as key-off drain,” puts wear and tear on a battery.

My infamous Corolla has a parasitic power drain somewhere and I don't know how to figure it out. Does anyone know how much it cost to fix this type of strange problem. It comes and go and sometime it persist for days and sometime it would occurs just once every 5 months. It has been going on for 5 years.

Table of Contents Show

How much is a parasitic drain?
What is the most common cause of an excessive parasitic drain?
How much does a battery draw test cost?
Can a parasitic drain ruin a battery?

mechtech2

JoinedSep 5, 2006Messages19,478LocationChicago Area

Apr 7, 2010

Get a common multimeter and set it to Amps. Put it in series with either battery cable to the battery. [requires taking off a cable, get it?] Then note the Amp reading. 25-50 MA is about normal - maybe a little more. Start pulling fuses to see which circuit is having a big draw.

scurvy

JoinedFeb 19, 2007Messages2,405LocationChicago IL USA

Apr 7, 2010

How much to fix it? I'll fix it for $40. Unhook your battery. No more parasitic drain! Paypal address is in my profile. Thanks!

You need to take some time to diagnose the problem. It might be free & easy or it could be several hundred dollars to replace a faulty component and the same - or more - to properly diagnose it. Start out by keeping track of when it happens and what circumstances lead to it.

ARCOgraphite

JoinedMay 17, 2009Messages18,644LocationN.H, U.S.A.

Apr 7, 2010

Many times its a 1) broken lighted vanity mirror wire, corroded bulb terminals, courtesy light on always (check boot area or hatch or under bonnet) Shorted power-seat wire or seatbelt reminder under DS or PS seat shorting to seat spring. These are a few I have found when I was a mechanic. I will assume you would see the A brake light SWITCH STUCK on

JHZR2

Staff member

JoinedDec 14, 2002Messages49,022LocationNew Jersey

Apr 7, 2010

Good list!!!

ARCOgraphite

JoinedMay 17, 2009Messages18,644LocationN.H, U.S.A.

Apr 7, 2010

I forgot: puddle lamps on doors - and other wiring through door hinge area. Good luck!

Colt45ws

JoinedAug 15, 2006Messages10,060LocationCentral Washington

Apr 7, 2010

Ive had terrible luck trying to test for a parasitic load on my Vic. I cant get the multimeter to keep a connection when I disconnect the battery so everything resets.

mechtech2

JoinedSep 5, 2006Messages19,478LocationChicago Area

Apr 8, 2010

Colt - Get some clamps - alligator clamps or whatever.

Colt45ws

JoinedAug 15, 2006Messages10,060LocationCentral Washington

Apr 8, 2010

I was able to get it done last night. I got .25A of draw. I traced it to the power point fuse as it dropped to nearly nothing. I removed my GPS then closed my door which interrupted power for a moment. The lighting control tried to flash my headlights when it reset (forgot about that) and smoked my DMM. I pulled the DMM apart and found a burned trace on the board attached to the plugs. I scraped off the material covering the trace. Then I was able to tin the trace with solder. Tried again (pulled the headlight fuse this time) and got 40mA.

SuperBusa

JoinedMar 2, 2009Messages2,371LocationWA

Apr 8, 2010

Originally Posted By: M1Accord

Does it actually drain the battery? Have you measured the parasitic current level? ... what did you measure. You never said. Did you let everything sit undisturbed for 45+ minutes after you hooked up the current draw test equipment? I've found that many newer cars take a while for the computers to go into full "sleep mode". http://www.bobistheoilguy.com/forums/ubb...748#Post1841748

hooligan24

JoinedSep 5, 2007Messages903Locationwa state

Apr 8, 2010

So, if the meter is reading between 25-50MA and you happen to pull the fuse on the system that is causing the draw, what will the muilt meter do?

Colt45ws

JoinedAug 15, 2006Messages10,060LocationCentral Washington

Apr 8, 2010

Should go lower. Although I also had an issue when I pulled a fuse it caused a relay to rapidly cycle for some reason, so the load went up. 25-50mA is an acceptable number, though.

brianl703

JoinedMay 7, 2004Messages12,767LocationNokesville, VA

Apr 9, 2010

Originally Posted By: Colt45ws

Ive had terrible luck trying to test for a parasitic load on my Vic. I cant get the multimeter to keep a connection when I disconnect the battery so everything resets.

You could try an inductive ammeter. Sears has one for $59 (model 82369). They can measure down to 100mA.

SuperBusa

JoinedMar 2, 2009Messages2,371LocationWA

Apr 9, 2010

Originally Posted By: brianl703

Originally Posted By: Colt45ws

Ive had terrible luck trying to test for a parasitic load on my Vic. I cant get the multimeter to keep a connection when I disconnect the battery so everything resets.

You could try an inductive ammeter. Sears has one for $59 (model 82369). They can measure down to 100mA.

IMO, you need a meter that will measure down to 1 mA. Most cars have a normal parasitic current draw around 20 mA. I guess you could use the inductive ammeter that measures down to 100 mA to find a large draw, but it wouldn't give accurate data if trying to measure a normal current draw.

How much is a parasitic drain?

Causes of Parasitic Battery Drain Typically, the normal amount of parasitic draw is between 50 and 85 milliamps in newer cars and less than 50 milliamps for older cars.

What is the most common cause of an excessive parasitic drain?

A parasitic battery drain is just something that consistently and continually drains your battery. This could be a faulty relay, a headlight/dome-light switch, alternator, or any other electrical gremlins.

How much does a battery draw test cost?

The Best in Auto Repair The average cost for battery test is between $35 and $45.

Can a parasitic drain ruin a battery?

What's the Danger of Parasitic Drain? If a battery goes long periods without being recharged by the alternator, those tiny milliamps drawn by parasitic devices will kill it. Even normal parasitic drain, also known as “key-off drain,” puts wear and tear on a battery.