Electrical & Lights Parasitic Battery Drain - any ideas?

Discussion in '7th Generation (2003-2008) [Acura TSX]' started by ooh, Thursday 11th Apr, 2019.

  1. ooh New Member Getting Started

    United Kingdom Olly Chester
    9
    1
    Hi All. Long time lurker, first time poster!

    I have a 2007 Tourer that seems to have a parasitic battery drain. I've done some tests but am coming up short, and would appreciate any input!

    Bought car a few weeks ago. Left car on the drive for 2 weeks, battery completely dead. So much so that the alarm went off when jump starting. Ran car for an hour to recharge the battery as I didn't have a stand alone battery charger. Assumed I'd done something that caused the drain. At the time, the power tailgate failed, gave the PTG light on the dash. disconnected the battery and reconnected, all reset and working again.

    3 days later, battery too low to start car, but enough to light dash etc. Jump started and took for a long drive.
    Then wouldn't last for more than a day or so. Assumed battery was goosed.

    Replaced battery on Wednesday. Made sure it was fully charged and got a multi-meter to start testing. Battery at 12.6v, disconnected the negative lead and connected the multi-meter to look for parasitic drain. On connection I got 0.3a, which dropped to 0 after a second or two. If I made the car drain by opening a door, the meter read an output, so the meter was doing its job but couldn't get a consistent drain to register.

    Car has a towbar, aftermarket reversing sensors and an aux input cable fitted. All now disconnected in-case they were the cause.

    Within 12 hours the battery had dropped to 12.3v, still enough to start the car but obviously dropping fast.

    Alternator test shows 14.2v at idle, 13.8v at full load - lights, ac, radio, fog. So alternator seems OK in the output.

    Seems like a pretty significant drain, and more than just an interior lamp causing it.

    Anyone got any ideas on what it could be? Could the power tailgate ECU drain this quickly?

    Thanks everyone!!
     
  2. JapCar Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Bristol
    49
    16
    It's not clear your explanation... First 0.3A then dropped to 0A? It couldn't be 0A, normally is about 0.03-0.05A (30-50mA) (immobilizer, alarm, central locking...)
    When there is extra drain, usual suspect is blue toot module. Disconnect it and test again. Look in you tube or forum whre it is...
     
  3. ooh New Member Getting Started

    United Kingdom Olly Chester
    9
    1
    Sorry - when I connected the multi-meter in sequence, one end to the negative terminal of the battery, one to the disconnected negative cable, I got an immediate reading of 0.3a, which dropped to 0 in around a second. Wouldn't read any output at all.

    If I switched on an interior light it immediately showed a reading, so the meter did seem to be working. It's only a cheap one though so perhaps it's not being accurate.

    Forgot to mention I read on this site about the Bluetooth module. I have already disconnected this as it wasn't working but was still plugged in.

    Hope this helps, sorry it wasn't clear first time.
     
  4. JapCar Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Bristol
    49
    16
    You repeat the same... There is something wrong...couldn't be 0A drain. (check multimeter dial/switch to be DC, not AC)
    Check again, no meter negative or positive terminal disconnected, just multimeter should be in series. Make sure proper connecting terminals
    to multimeter ( 0/A, not V and A or mA, DC, not AC).
     
  5. ooh New Member Getting Started

    United Kingdom Olly Chester
    9
    1
    I do repeat the same because it's true! Perhaps the multimeter wasn't functioning correctly on the lower volumes but it was set up correctly as it would register a drain if I opened a door or left an interior light on.

    If it wasn't set up correctly, it wouldn't have registered the higher drain?

    It was in series, negative lead disconnected, multimeter in series between the battery and the ground.

    As I say, perhaps my multimeter isn't reading at such low values correctly.

    Any ideas what the source could be considering it is quite a significant drain?
     
  6. JapCar Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Bristol
    49
    16
    Why you look for a drain if you can't register any now (0A) ? (again, normal is 0.03-0.05)
    How much is when open a door, when switch on headlights continuous ?
     
  7. ooh New Member Getting Started

    United Kingdom Olly Chester
    9
    1
    Why look for a drain? Because my battery is draining quickly when parked up and I can't find the source for it.

    I imagine the issue of not registering any draw at all is an issue with my cheap multimeter, but considering the draw seems to be significant, I'm keen to see if anyone might have ideas on what on the car could be draining so heavily. Could it a diode in the alternator, or for example, would the ECU for the auto tailgate drain this heavily? Are there any key areas I should be looking into as I assume an interior light relay for example wouldn't drain the battery as quickly as it is.

    Thanks for the help so far.
     
  8. JapCar Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Bristol
    49
    16
    I can't answer your questions, probably somebody else...
    Any cheap multimeter can register approximately small drain about 50mA if it's working, it's not necessary accuracy.
    I will ask again: "How much is drain when open a door, and when switch on headlights continuous ? " (for headlights multimeter should be on 10A or more range)
    Better if is possible, post here a picture just of your multimeter and position of probes and switches.
     
  9. Sandy52 Senior Member ★ ★ ☆ ☆ ☆

    United Kingdom Sandy NORWICH
    264
    122
    A new fully charged battery should read more than 12.6v when full disconnected. Should read at least 13.5v if not more.

    check your battery connections positive and -ve, for loose connections and or corrosion. Check your battery earth to the bodywork.
     
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  10. ooh New Member Getting Started

    United Kingdom Olly Chester
    9
    1
    Hi Sandy, thanks for that info - I thought the battery was fully charged at 12.6v, is that the lowest it should read to be considered fully charged? I didn't realise it could read so much higher.

    I have removed and cleaned the negative lead, both connecting to the body and to the terminal. The positive all seems clean enough.

    Perhaps I need to take it for a long drive with the new battery in to make sure it's charged well over what I thought was "full"

    Even then though, a drain the pace it's currently experiencing seems high don't you think?
     
  11. tenz78 Top Contributor ★ ★ ★ ★ ☆

    United Kingdom Matthew MARKET RASEN
    695
    108
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  12. ooh New Member Getting Started

    United Kingdom Olly Chester
    9
    1
    Japcar - headlights were draining at just under 10a, ignition on but engine not running, nothing else on. An interior light on its own was drawing approx 3a from memory.
    - - - Updated - - -
    Thanks Tenz, as noted a little earlier in the thread (forgot about it in the OP) I have already disconnected the HFT.
     
    tenz78 likes this.
  13. Sandy52 Senior Member ★ ★ ☆ ☆ ☆

    United Kingdom Sandy NORWICH
    264
    122
    Some new batteries can show 14.5v approx when fully charged. Minimum would be about 13.5v fully charged. Mine shows about ~14v but it is over a year old. Just running the car may not charge it 100%. Obviously depends on the output of the alternator, length of the journey, and the circuitry. I use trickle chargers on my very old (50 years old) Mercedes engine and they keep the battery at approx 14v. After running, the batteries are not at 100%, so the trickle charger stays on most of the time, even over winter.

    The battery drain should be very low, less than 0.1 amps, even down to 0.05 amps. ANything more than that needs to be investigated and fixed. Disconnect the battery for 30 minutes. Then have you removed all the main fuses, where possible, and auxiliary fuses and then checked for the drain and slowly fit the fuses back and check the drain if any? Even reversing sensors, alarm, or any aftermarket kit, or corroded connections can cause weird problems. Alarms can be a big problem as they are linked to all sorts of car systems. Maybe isolate/disconnect the alarm first?

    Let us know how you get on.
    Good luck.
     
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  14. ooh New Member Getting Started

    United Kingdom Olly Chester
    9
    1
    Thanks Sandy. I've disconnected all aftermarket stuff, it has a towbar and retrofit reversing sensors, along with a aux input cable box. All completely removed.

    My main difficulty seems to be getting the car show any sort of draw on the multimeter when in sequence. It gives me 0.3a for a second then immediately drops to 0 and stays there. If I retain it in sequence and switch an interior light on, the multimeter will show the draw. Turn it off, back to 0. So the multimeter is working at a higher amp draw but perhaps is failing on milliamps.

    I'm going to have to get an auto electrician to have a look at the weekend.

    I'll keep you.posted with the outcome, thanks for the advice so far!
     
  15. DrSam Club Moderator Club Staff

    United Kingdom Sam Birmingham
    2,200
    1,478
    Hello @ooh welcome to Club H-Tune
    it's customary for new members to introduce themselves via "Introduce Yourself".

    Please add your car to the Club Garage, as this will help us help you.
     
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  16. ooh New Member Getting Started

    United Kingdom Olly Chester
    9
    1
    Cheers Sam, will do this evening!
     
  17. JapCar Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Bristol
    49
    16
    Headlights consumption is OK but 3A for interior lights is much (that is 36W?) , probably is less... Anyway, strange, your multimeter doesn't work correctly at low current range, so it's difficult to investigate the drain.
    Normally when driving alternator charges battery to 14,2V, so after long trip should be 13.5-14V as Sandy mentioned. (not running engine). Good new fully charged battery should keep about 13-13.5V for 1-2 days. Old battery drops to 12.2-12.5V for a day...