2014 Toyota Sienna - Battery drain overnight

battery discharges over night

Ask your shop to measure the parasitic current draw on the battery. If you’ll post the number here (in mA units), I expect you’ll get some more ideas. Good idea for the shop to perform a battery/alternator test.

Things an owner could check during the overnight.

  • Brake lights off.
  • Interior lights , including “hidden” lights, such as the glove compartment, engine compartment, cargo area.
  • Dashboard lights off. If the “door open” dashboard light remains lit, suspect a problem with the door switch, usually in the pillar area of the door’s latch mechanism. The driver’s door is usually the first door switch to fail.
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Or a battery jus5 too old and frail to hold a charge. I had a one year old battery in a car that sat most of the time. Had a charger on it for 24 hours and not enough charge to start the car.

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When was the last time the battery was replaced? Batteries should last at least 3 years in a hot climate. I live in Maryland and get 3 years from my batteries. Your Sienna’s battery is under the hood so engine heat plus general environment heat reduces battery life the most. You can get your battery tested at a parts store. I get mine tested at a local Advance Auto while the battery is still in the car and they always provided an honest assessment. Any store like Advance should have a tester too.

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Just a heads-up. I’ve had pretty good luck rejuvenating a fairly new but very discharged battery by just keep trying. Recharge on low 2A rate overnight. Wait a day, recharge overnight 2A again, etc. Sometimes it takes 3 or 4 cycles, but a new-ish battery will usually begin to take a charge. This won’t work if battery is old & heat damaged.

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Didn’t have another day. Car was sold for $50. Got a Walmart replacement and filled the tank. Can’t mention the ancestry of the buyer in need or I’ll get flagged.

If you feel that information will help Buzz20 recharge the battery in the Sienna, send a private message.