The dreaded day arrived… battery dead.
I have been loving my new Toyota and I haven’t had any real issues with it over the past month that I’ve had it,but that’s just it— only one month of ownership. bought it new with 23 miles now it has about 1700 miles on it.
I saw numerous posts about 12 V battery dying. I figured this was more for people who only drive their car periodically so their battery never gets a chance to build and hold a decent charge. since I drive it so much, I figured this doesn’t apply to me. I have all my apps and features connected, including the DCM features and I haven’t had any problems before, and I didn’t really wanna mess with anything.
I then went on vacation for six days. Granted it was in the midst of a brutal heat wave, but I parked my car in the airport economy parking lot outdoors for those six days I was gone. I left it with about 33% charge. when I finally returned to the car after six days and it wouldn’t unlock with my fob, I figured the worst that happened and the battery was dead. I physically unlocked the car and no buttons were responsive. It wouldn’t start there were no lights sounds or anything.
I didn’t open the app a single time that I was gone. I guess that has no bearing on the drain situation.
They sent out AAA person after I called the Toyota roadside assistance to jump it. He jumped it and also tested it, and these were the results for my one month old brand new car:
Thank you for the opportunity to test your battery. Below you will find the test results:
Service Call:
Date: 7/5/2026
Test Data:
Overall Result: BAD & REPLACE
This battery has reached its end of life. Immediate replacement is advised.
State of Health: 76%
State of Charge: 100%
Voltage: 12.74 V
Battery Details:
Type: FLOODED
Set Capacity: 290 CCA/SAE
Measure Capacity: 222 CCA/SAE
System Details:
Starter Voltage: NO DETECTED / 0 V
Idle Voltage: NORMAL / 13.98 V
Idle (with load) Voltage: NORMAL / 14.08 V
Diode Ripple: NORMAL / 0.28 V
He told me that it’s not anything car or model specific; that it’s likely more to do with the heat, and simply not driving it for six days will have this impact on any type of car and he warned me not to overreact. However, my parents car was in the same lot parked very close by dealing with the same heat with a four-year-old battery and it had no problems starting.
The service center at my dealership is closed today so tomorrow morning I wanted to take it in, but I wanted to call them beforehand and explain but also ask how this happened. I don’t buy the heat excuse. He also said that the batteries Toyota provides are often kind of like the batteries that come with a toy: they’re cheap and they can hold the charge but leaving them alone for a while often causes this kind of issue. he recommended I replaced it with AGM battery but not at first, in order to save money. He told me I should call the dealership and say hey this is a new car. I just bought it a month ago. I left it for six days. It died and the battery tested bad. Why did this happen and what can you do to fix it?
The sales person I bought the car from initially doesn’t even work there anymore. I’m worried about how scummy dealerships can be and if they’re gonna try and weasel their way out of this one.
I doubt they will replace this battery with an AGM battery without some kind of up charge however it should be on them to replace this battery. I also still have no answer regarding the DCM issue although the post that I’ve seen make it seem like that’s a forgone conclusion that the DCM is causing drainage with the connection to the app.
Tips or recommendations on how to handle this if you’ve dealt with it before would be much appreciated. I already ordered a jump pack in case this happens again, but the fact that the battery tested bad means that of course it has to be replaced. I just didn’t expect this to happen so soon. any advice is welcome.