Jump starting

After it dies when you disconnect the jump pack if you step on the gas does the engine come back to life It's waiting for you to sit in the car and drive it? And if not what would happen if you left your jump box connected to the jumper spot under the hood and just set the hood down where the first latch catches so it doesn't fly up and you ride around the neighborhood does that work? If so do that for a few minutes and see if your blue line start to climb on the MFD If it does pull over and undo the jump pack the engine may stop close the hood get in the car and step on the gas like you're going to go and see if it goes ...wella

 

If the 12V battery is really discharged, the best way to deal with it is to (slowly) charge it with a "smart" (AGM compatible) charger. Can take 12 hours or more.

If you jump start the car, the DC-DC converter should take over and supply "12V" power once you've gone ready.

BUT, I have seen a really flat Prius AGM suck up 70-80 amps for a time after using a booster pack to go ready. Could be that your battery draw momentarily exceeded the converter's output? Can't say for sure.

Or, the throttle body is dirty and the ECM reset learned idle values when the 12V went flat. When you "started" the car, maybe the ICE never actually ran, but instead the car spun it at 1000 rpm for 10 seconds TRYING to run before ceasing the attempt.

Posted via the PriusChat mobile app.

 

let's stop using the word 'start', and use toyota's term, 'ready'. if the jump pack made the car ready, and it shut off after you removed it, you need to replace the 12v.

these cars aren't 'finnicky' if they don't need repairs, but if they do, it can be complicated.

 

Jump starting is very short-term, stop/gap measure. Driving around to charge a near-dead battery is prett much a fools-mission.

charging with a decent smart-charger “may” revive it. If not: replacement time.