battery reserve

My wife's sienna has a two year old battery that seems like it is on the way out, but every time I have it tested at vatozone they say it tests fine.

it seems like if you leave an overhead lamp on or the headlights on for more than 5 mins the battery is ran down enough that it won't crank. It'll go weeks with no issue, but if you forget to hit the 'lock' button twice and have the headlights on it will run the battery down before they automatically go off. I have the overhead lights turned off by default just to make sure one of the kids doesn't accidentally leave one on and run the battery down.

can I demand a new battery (it's a 5 yr warranty battery) or is there another cause to this that I'm not aware of?

 

https://www.tacomaworld.com/threads/battery-drain.164828/

 

Based on what you've written (i.e. problem doesn't occur if you make sure headlights and dome lights are off), the vehicle electrical system should be OK. An average group 35 battery has about 90 minutes reserve capacity. No reason for it to die after 5 minutes with just the draw from lights. Maybe try a different store, in case that particular store's battery load tester was faulty?

If you really want to confirm the vehicle electrical system is OK, you'd need a multimeter with a current clamp, something like this ($27): https://www.amazon.com/Tacklife-Multimeter-Auto-ranging-Voltmeter-Resistance/dp/B01N014USE/ . Measure the DC amperage on one battery cable. Each headlight bulb draws, what, 55W? 55Wx2/12V = 9.2A. If you see significantly more than 10A with the engine off and headlights on, then there's a parasitic draw somewhere. Otherwise the vehicle electrical system is OK.