I just purchased a slightly used 2025 TX-350 with 1,300 miles on it and have had what appear to be battery/power problems with it over the last several weeks. Toyota installed "380LN3-ISS" batteries in this model - apparently, the same battery that they have been installing in their Toyota line of vehicles. Can someone explain to me WHY they didn't use a heavier-duty battery, given the heavy use of power needs in the TX-350?

 

My guess is they probably installed the same battery used in the Grand Highlander as they are essentially the same platform. Nothing wrong with assuming they used the correct battery. I suspect you have some sort of other electrical issue going on and the problem is not the battery.

 

I was surprised that Toyota didn’t use an AGM battery due to the heavy constant use of the battery prior to and after turning on/off the engine. AGM’s, I believe are designed to be used in todays heavy use batteries?

 

Yes, I agree. Interestingly, when I took it back to the dealer and they load tested the existing battery, they found it to be defective and they replaced it with an 84-month Lexus-brand battery.

 

Just a bad battery - it happens