Well, the first time I came out to a stone-dead car (no response or boot-up at all) I went and bought a new battery. The second and third times (even with new battery), I jumped it at the terminal under the hood. Now it's the fourth time in 3 weeks! Headlight switch is at OFF position. All accessory chargers are disconnected. I can't see anything powered up to drain the battery at all. Any ideas WTH?
If you 'report' your duplicates, they will be cleaned up. Otherwise, you are just hoping they read this, and they may not.
This Eric the Car Guy goes into troubleshooting excess car-off loads. If you splice in an ammeter between negative post and ground, you should be seeing 15~20 milliamps, with maybe occasional slight up-spikes, to around 40.
start by checking the voltage after you shut down, then at one hour intervals to see how fast it's dropping. could be you just have a low battery. make sure all the lights are out after closing the doors.
If any door or the hatch is not fully closed and latched, it will be more like 700mA, enough to kill the battery within a couple of days, even if no lights are on.
Is the vehicle locked every evening? If you get lock confirmation you can be assured that all doors are fully latched. On a side note some forum members have reported their aftermarket dash cams were killing off their 12v.
Did you measure the new battery voltage so it had a decent charge on it before installing first? If not, same result can occur.
This has happen on my 2010 prius ,the battery stays charged for weeks at a time then it happens ,a no start ,I get the jumper pack (three batterys replaced ) I had it in the toyota shop for three days with no results they mentioned the rear hatch. To me it's like a relay that's open. When I jump it the 12 v battery will run everything again without recharging Last week the CUT sounded like it was in B as I came off the Interstate them dash lights flickered I put the jumper pack on it, it reset sometime it's good for now Posted via the PriusChat mobile app.
Jump starting and a drive is not going to restore a depleted battery. I would get it assessed with an electronic load tester, then if it's viable hook it up to a smart charger for a complete charging session.
How close are your Prius smart key to the vehicle? They can be communicating and stuff while Prius is not in ready mode.
Well you need to see where the battery voltage lives and get a sense of how healthy it is. Reports of bad new batteries. The Prius is a pain in the nice person 12 volt battery wise you have to be aware of this issue with this car. You have to own a voltmeter. You have to own a decent battery charger and throw it on the battery once a month and pay attention for a few minutes what its charging behavior looks like . If it takes a long time to charge it you know somethings going on and its struggling. If it charges right up and pulls some good current when you first start the charge your usually ok. The 12 volt in this car requires alot of attention. Its the most posted subject on this site. Like its some big mystery. You have to arm the car alarm every single time you get out of the car. If any door is ajar when you park at night it will not arm alerting you. Especially arm it in the garage and peek at the car before you go to bed. I peek at all my cars before I go to bed. I make sure there all locked and lights off. Just about every poster on here with repeat battery failure does not do this. And kids will kill you. They mess around with the car and leave the door ajar. Please see my check car before bed part. I bought a yellow top years ago with a 3 year warranty. With my charger test I noticed all of a sudden one month it would not charge up fast. It dropped 2 volts overnight from full charge. Sure enough next morning I see the red exclamation point flash on the dash. The car started so off I go to autozone. I was one day shy of the 3 years warranty but they know me pretty good and gave me a new battery. It measured 12.3 volts new. It got a full charge before going in and that was 2 years ago and I watch it like a hawk. Its momma's car. She hasn't been stuck yet but its work. Just like checking the oil. Every saturday before I start my cars. I know who's eating a little oil and who isn't. Cars are a pain in the nice person they take more maintenance than anything in your life. Except marriage.
