Battery drain without Bluetooth module (2009 ES)
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Battery drain without Bluetooth module (2009 ES)
Problem:
My 2009 ES Lancer has been draining batteries since I had it (bought in 2020, went through multiple batteries because they always get drained and freeze during winter). If I let it sit for more than a week during summer or about 2-3 days during winter the battery is completely flat to the point where I can't even unlock the doors without using the key.
What I did so far:
At this point I'm pretty much certain there are no spikes that happen at a constant enough interval to drain the battery. I'm more of a electronics/computers guy so I don't really have the intuition to know what else I can do to find the cause of this mystery battery drain. I've heard that some cars can show a parasitic drain only when in "sleep mode" but I haven't found any information on how long it takes for this specific car to get there. I pretty much left it untouched for 3 hours with the shunt connected so I could just come and measure the voltage without disrupting any part of the circuit and it showed the exact same thing as I've described above. Maybe that wasn't long enough?
Some people I talked to even claimed it's normal for a car battery to go dead after a few days especially during winter but I don't buy that. My previous Lancer (a 2003 oz rally) never had this type of issue and I was only using it like once a week.
If anyone has any tips on what else I can do to find what drains my batteries, or maybe if you think I did something wrong in my troubleshooting process, I'd really appreciate the help!
My 2009 ES Lancer has been draining batteries since I had it (bought in 2020, went through multiple batteries because they always get drained and freeze during winter). If I let it sit for more than a week during summer or about 2-3 days during winter the battery is completely flat to the point where I can't even unlock the doors without using the key.
What I did so far:
- Tested the alternator and battery, both are ok, the battery passes load testing and the alternator charges it fine. Actually never have issues starting the car if it's been started the previous day.
- Went on to look for parasitic drain, checking with a multimeter I see a mere 36mA to 40mA draw, which even for a 40Ah battery should last more than a month before being completely drained.
- Looked for the infamous Bluetooth module. As I looked all over the internet looking for solutions I noticed that this car is notorious for draining batteries due to a faulty Bluetooth module. After removing the plastic cover above the glove box I only found the connector so I'm assuming the previous owner had already removed it likely in an attempt to fix the same battery issue. In hindsight it makes sense that this isn't the issue because from what I can see that module usually draws more current when faulty.
- To check for fast current spikes that might not be caught by a multimeter I hooked up the battery through a shunt resistor (basically turns amperage into voltage, that's how multimeters do it) and measured the voltage across the shunt using a handheld oscilloscope. Long story short, it doesn't show any current spikes big enough to drain the battery in a few days. I see constant 56mA spikes and some rare 68mA spikes. I recorded two videos for those that want to see for themselves:
Note: the vertical scale is 10mv per division and my shunt is calibrated to give 10mV per mA so multiplying the voltage by 10 gives the amperage.
This one shows a slow 1 second per horizontal division, there are visible jumps at 1.5 second intervals. This is actually the blinking red light next to the hazards button.
This one shows a fast 5ns per horizontal division, triggering on a 5.6mV (56mA) rising edge. It shows a there are constant spikes up to about 60mA that are hidden in slower sample rates.
This one shows a slow 1 second per horizontal division, there are visible jumps at 1.5 second intervals. This is actually the blinking red light next to the hazards button.
5. I put the oscilloscope in peak detect mode which showed the constant spikes even in a slow sampling rate. I then started pulling fuses while looking for a change in peak current draw but nothing made a big difference. Pulling the IOD fuse actually made the current draw go up for a little bit but it returned to a similar level after a few seconds.
At this point I'm pretty much certain there are no spikes that happen at a constant enough interval to drain the battery. I'm more of a electronics/computers guy so I don't really have the intuition to know what else I can do to find the cause of this mystery battery drain. I've heard that some cars can show a parasitic drain only when in "sleep mode" but I haven't found any information on how long it takes for this specific car to get there. I pretty much left it untouched for 3 hours with the shunt connected so I could just come and measure the voltage without disrupting any part of the circuit and it showed the exact same thing as I've described above. Maybe that wasn't long enough?
Some people I talked to even claimed it's normal for a car battery to go dead after a few days especially during winter but I don't buy that. My previous Lancer (a 2003 oz rally) never had this type of issue and I was only using it like once a week.
If anyone has any tips on what else I can do to find what drains my batteries, or maybe if you think I did something wrong in my troubleshooting process, I'd really appreciate the help!
Last edited by r3eckon; Dec 12, 2024 at 12:58 PM. Reason: formatting
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Battery drain
Problem:
My 2009 ES Lancer has been draining batteries since I had it (bought in 2020, went through multiple batteries because they always get drained and freeze during winter). If I let it sit for more than a week during summer or about 2-3 days during winter the battery is completely flat to the point where I can't even unlock the doors without using the key.
What I did so far:
At this point I'm pretty much certain there are no spikes that happen at a constant enough interval to drain the battery. I'm more of a electronics/computers guy so I don't really have the intuition to know what else I can do to find the cause of this mystery battery drain. I've heard that some cars can show a parasitic drain only when in "sleep mode" but I haven't found any information on how long it takes for this specific car to get there. I pretty much left it untouched for 3 hours with the shunt connected so I could just come and measure the voltage without disrupting any part of the circuit and it showed the exact same thing as I've described above. Maybe that wasn't long enough?
Some people I talked to even claimed it's normal for a car battery to go dead after a few days especially during winter but I don't buy that. My previous Lancer (a 2003 oz rally) never had this type of issue and I was only using it like once a week.
If anyone has any tips on what else I can do to find what drains my batteries, or maybe if you think I did something wrong in my troubleshooting process, I'd really appreciate the help!
My 2009 ES Lancer has been draining batteries since I had it (bought in 2020, went through multiple batteries because they always get drained and freeze during winter). If I let it sit for more than a week during summer or about 2-3 days during winter the battery is completely flat to the point where I can't even unlock the doors without using the key.
What I did so far:
- Tested the alternator and battery, both are ok, the battery passes load testing and the alternator charges it fine. Actually never have issues starting the car if it's been started the previous day.
- Went on to look for parasitic drain, checking with a multimeter I see a mere 36mA to 40mA draw, which even for a 40Ah battery should last more than a month before being completely drained.
- Looked for the infamous Bluetooth module. As I looked all over the internet looking for solutions I noticed that this car is notorious for draining batteries due to a faulty Bluetooth module. After removing the plastic cover above the glove box I only found the connector so I'm assuming the previous owner had already removed it likely in an attempt to fix the same battery issue. In hindsight it makes sense that this isn't the issue because from what I can see that module usually draws more current when faulty.
- To check for fast current spikes that might not be caught by a multimeter I hooked up the battery through a shunt resistor (basically turns amperage into voltage, that's how multimeters do it) and measured the voltage across the shunt using a handheld oscilloscope. Long story short, it doesn't show any current spikes big enough to drain the battery in a few days. I see constant 56mA spikes and some rare 68mA spikes. I recorded two videos for those that want to see for themselves:
Note: the vertical scale is 10mv per division and my shunt is calibrated to give 10mV per mA so multiplying the voltage by 10 gives the amperage.
This one shows a slow 1 second per horizontal division, there are visible jumps at 1.5 second intervals. This is actually the blinking red light next to the hazards button.
The first one
This one shows a fast 5ns per horizontal division, triggering on a 5.6mV (56mA) rising edge. It shows a there are constant spikes up to about 60mA that are hidden in slower sample rates.
The second one
This one shows a slow 1 second per horizontal division, there are visible jumps at 1.5 second intervals. This is actually the blinking red light next to the hazards button.
The first one
This one shows a fast 5ns per horizontal division, triggering on a 5.6mV (56mA) rising edge. It shows a there are constant spikes up to about 60mA that are hidden in slower sample rates.
The second one
5. I put the oscilloscope in peak detect mode which showed the constant spikes even in a slow sampling rate. I then started pulling fuses while looking for a change in peak current draw but nothing made a big difference. Pulling the IOD fuse actually made the current draw go up for a little bit but it returned to a similar level after a few seconds.
At this point I'm pretty much certain there are no spikes that happen at a constant enough interval to drain the battery. I'm more of a electronics/computers guy so I don't really have the intuition to know what else I can do to find the cause of this mystery battery drain. I've heard that some cars can show a parasitic drain only when in "sleep mode" but I haven't found any information on how long it takes for this specific car to get there. I pretty much left it untouched for 3 hours with the shunt connected so I could just come and measure the voltage without disrupting any part of the circuit and it showed the exact same thing as I've described above. Maybe that wasn't long enough?
Some people I talked to even claimed it's normal for a car battery to go dead after a few days especially during winter but I don't buy that. My previous Lancer (a 2003 oz rally) never had this type of issue and I was only using it like once a week.
If anyone has any tips on what else I can do to find what drains my batteries, or maybe if you think I did something wrong in my troubleshooting process, I'd really appreciate the help!
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Joined: Dec 2024
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From: Canada
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xisien
Lancer Troubleshooting
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Jul 1, 2009 07:12 AM