[dlindqui]

Hello,

I recently bought a 2021 Corolla and I'm having an issue where the battery will die if I leave the car for more than 2 or so days. It will start if I've left it for 2 days or less but more than that and most often the car won't start and when I've left it for 4 or more days the keyless entry buttons won't work. It will jump start right away and I'll drive it for a while afterwards to charge up the battery but I keep having the same issue. It doesn't seem like its a battery or alternator issue since it will jump start right away and will start as long as I don't leave it for over 2 days. It feels like I'm leaving a light on somewhere or that something is draining the battery. I've made sure that the headlights are turned off and unplugged the cord I use to connect my phone. After I lock the car I look and don't notice any lights that are still on. There does seem to be a red light on the dash indicating that the car is locked. If anyone has any thoughts or ideas regarding what might be causing the issue I would really appreciate it.

Thanks!

Edit: 2021 Corolla with ~ 45k miles. Will try to update the firmware tonight.

Edit 2: Found this thread so going to go through those TSBs - T-SB-0095-20 | 2020-2021 | DCM Reset and Firmware Update...

 

[PJTruslow]

has the battery been replaced? Once a car battery has been deeply discharged, damage is done. A couple of those and the battery should never be trusted again. if you bought the car used, the history of the battery is unknown. If it was a dealer that sold you the car, maybe try calling them and see if they are willing to pay for a battery replacement.

there are two possible causes of what you are describing. either there is some parasitic load running on the order of a few tenths of an amp, judging by how long it takes to die, or the battery has been damaged enough to cause high self discharge. This would require a multimeter to diagnose confidently.
the red light on the dash is normal and doesn't contribute to the car battery discharging in any meaningful way.

 

[dlindqui]

has the battery been replaced? Once a car battery has been deeply discharged, damage is done. A couple of those and the battery should never be trusted again. if you bought the car used, the history of the battery is unknown. If it was a dealer that sold you the car, maybe try calling them and see if they are willing to pay for a battery replacement.

there are two possible causes of what you are describing. either there is some parasitic load running on the order of a few tenths of an amp, judging by how long it takes to die, or the battery has been damaged enough to cause high self discharge. This would require a multimeter to diagnose confidently.
the red light on the dash is normal and doesn't contribute to the car battery discharging in any meaningful way.

Thank you for your comment! I believe that the battery is the original. The Car Fax notes that the "Battery/charging system" were checked at 40,000 and 42,500 miles but battery replacement is not noted anywhere on the report. I'm making an appointment to get the battery tested at a dealership and see if there's a dead cell or an issue with T-TT-0625-20 or T-SB-0095-20. Will update with what I find out.

 

[75aces]

Hello,

I recently bought a 2021 Corolla and I'm having an issue where the battery will die if I leave the car for more than 2 or so days. It will start if I've left it for 2 days or less but more than that and most often the car won't start and when I've left it for 4 or more days the keyless entry buttons won't work. It will jump start right away and I'll drive it for a while afterwards to charge up the battery but I keep having the same issue. It doesn't seem like its a battery or alternator issue since it will jump start right away and will start as long as I don't leave it for over 2 days. It feels like I'm leaving a light on somewhere or that something is draining the battery. I've made sure that the headlights are turned off and unplugged the cord I use to connect my phone. After I lock the car I look and don't notice any lights that are still on. There does seem to be a red light on the dash indicating that the car is locked. If anyone has any thoughts or ideas regarding what might be causing the issue I would really appreciate it.

Thanks!

Edit: 2021 Corolla with ~ 45k miles. Will try to update the firmware tonight.

Edit 2: Found this thread so going to go through those TSBs - T-SB-0095-20 | 2020-2021 | DCM Reset and Firmware Update...

Do you have the smart key system? The proximity sensor will stay active when keys are within range. Not sure how to prevent battery drain. I’ve seen this mentioned by Avalon forum.

 

[dlindqui]

I don't believe that I have the Smart Key System. I have a key fob with a flip key similar to the one in the following link: https://fccid.io/HYQ12BFB/External-Photos/Short-Term-Confidential-External-Photo-2948660.pdf.

 

[75aces]

I’d check to see if you have any parasitic draws on the fuse boxes.

 

[YuryiPo]

I’d check to see if you have any parasitic draws on the fuse boxes.

Thank you. I'll check it out. I have the same problem.

 

[dlindqui]

I took it into the dealership for diagnostics on starter, alternator, battery, and for parasitic draws. Was told that battery needs to be replaced. Declined the dealership battery and going to buy an Interstate battery since I’ve had good experiences with those. In retrospect should’ve just bought a multimeter and a new battery. Thanks to everyone for the help.

 

[Glk21c]

Just one more thing to check. the alarm on the car, is it OEM or aftermarket? If not OEM and it's hooked up incorrectly, your new battery won't have much of a chance either. Good luck

 

[PJTruslow]

I took it into the dealership for diagnostics on starter, alternator, battery, and for parasitic draws. Was told that battery needs to be replaced. Declined the dealership battery and going to buy an Interstate battery since I’ve had good experiences with those. In retrospect should’ve just bought a multimeter and a new battery. Thanks to everyone for the help.

If you still want to get a multimeter, I recommend the UNI-T UT203+. it can be had for $45 on amazon, and has a DC current clamp. this means that you can measure current with reasonable accuracy without disconnecting wires or breaking a circuit, just hold the clamp next to the wire and zero it (to cancel out the stray magnetic fields at that point and orientation) then open the clamp and close it around the wire you want to measure. DC current clamps are amazing, with the only caveat that they pick up stray magnetic fields by their nature so you have to zero them out in whatever position and orientation you do your measurement in if you need it more accurate than +- 0.2A or so.
just an FYI, not all current clamps can do DC, as a much simpler method can be used to measure AC current. this UNI-T meter is the cheapest I have seen a DC clamp from a brand that I actually trust to not blow up when I try to probe 120V mains.

Personally I don't think it matters much what brand battery you get for flooded batteries, treat it right and it will last 5 years, run accessories with the engine off frequently, it'll last 2-3. run it down to the point it won't start the car more than a few times, it's toast. I buy what's cheap.

 

[alanwagen]

I took it into the dealership for diagnostics on starter, alternator, battery, and for parasitic draws. Was told that battery needs to be replaced. Declined the dealership battery and going to buy an Interstate battery since I’ve had good experiences with those. In retrospect should’ve just bought a multimeter and a new battery. Thanks to everyone for the help.

The OEM battery is probably cheaper than the Interstate and has a 7 year warranty. I only paid $165 for mine.

 

[dlindqui]

The OEM battery is probably cheaper than the Interstate and has a 7 year warranty. I only paid $165 for mine.

The quote I got for the battery replacement was $289.00. I'm assuming that included labor (which I could easily do) but it had already been 5 hours (twice as long as their estimate) and I needed to be somewhere.

Edit: also why does the OEM battery have a 7 year warranty while the original battery the car comes with only have a 2 year warranty?

 

[alanwagen]

The quote I got for the battery replacement was $289.00. I'm assuming that included labor (which I could easily do) but it had already been 5 hours (twice as long as their estimate) and I needed to be somewhere.

Edit: also why does the OEM battery have a 7 year warranty while the original battery the car comes with only have a 2 year warranty?

Wow, that was expensive. Call another dealer. I don't know why it has a longer warranty, maybe the original factory batteries are cheaper or they just don't want to pay it. But in the old days, a new car could set on the lot a few months which is bad for the battery.

TrueStart Battery Event | Toyota Battery Event

I show only $179 for a battery.

https://parts.toyota.com/t/Toyota_2021_Corolla-Sedan-LE-VIN-starts-with-5-18L-AT/BATTERY.html

 

[dlindqui]

Wow, that was expensive. Call another dealer. I don't know why it has a longer warranty, maybe the original factory batteries are cheaper or they just don't want to pay it. But in the old days, a new car could set on the lot a few months which is bad for the battery.

TrueStart Battery Event | Toyota Battery Event

I show only $179 for a battery.

https://parts.toyota.com/t/Toyota_2021_Corolla-Sedan-LE-VIN-starts-with-5-18L-AT/BATTERY.html

Thank you! I'll try calling around to see what I can find for the price just for the battery.

 

[Riick]

Costco...standard lead-acid battery still just under $100. 4 year warranty (?) Made by Interstate last time I looked.
You can either consider the cost of Costco membership a free perk, or, after buying battery, "return" the membership. (Yes, they WILL take it back)

 

[David314]

You need to measure the current draw after the car has been shut down for an hour or so.
if drawing more than say 50 milliamps it could be enough to discharge the battery to the point it will not start the car.
Trick is to find the source of the excessive current draw.
One way is to measure across the fuses to see the small voltage drop across them, in the order of millivolts.
Determine and write down which ones have a voltage drop and how much. Also note what those fuses control.
The ones that should not be active indicate the circuits to check.
Note: You will need a good schematic of the electrical system

 

[dlindqui]

Costco...standard lead-acid battery still just under $100. 4 year warranty (?) Made by Interstate last time I looked.
You can either consider the cost of Costco membership a free perk, or, after buying battery, "return" the membership. (Yes, they WILL take it back)

Will that fit in a 2021 Corolla? On the Interstate website the only recommended battery is the MTP-H4. Unfortunately the Costco automotive battery website is currently down so I can't check there right now.

 

[Spritanium]

My dashcam was causing the same problem until I turned parking mode off in the settings. Even with a low-voltage cutoff failsafe, it was discharging the battery to the point that the car wouldn't start.

It's interesting that a couple deep discharges can cause permanent damage though. Is there any reliable way to verify whether a battery is still healthy?

 

[Wheatwacked]

should’ve just bought a multimeter and a new battery.

A battery load tester $25 should be the first test.

 

[75aces]

A battery load tester $25 should be the first test.

Throw in a battery tender too