2007 Prius won't light up

changed my email recently too. Interesting bit of info: I used dual chargers, one on the big battery cranking out 255v and a 12v charger set on 50 amp start setting to turn on the lights

 

Why do people create a new account rather than use the Forgot Your Password option?

 

Usually because they think its less effort and the old account isn't much different to them than a new account.

How many amps you use to top off and balance hyrbid battery pack? Do you run the cooling fan when you do that?

 

I am really confused by the second part of that statement. What model 12V charger is that?

Sending 50 amps at "12V" into a 45Ah S46B24R battery is about 12.5X higher than the maximum charging current that type of battery should ever see, and will likely "put out its lights", permanently.

Doing the same thing to a HV pack module would destroy it in short order.

Is this 50A charger used to power up the car's 12V system instead of the 12V battery or the DC-DC converter in the inverter? There are some procedures that can take a long time and the battery can run down, and one might use a charger designed for this function in that case. That would make a lot more sense. For instance, the PRO-LOGIX PL2320 has a setting for that. However, it just has a "power supply" setting and the current cannot be set separately (it supplies up to 20A). True adjustable power supplies (sometimes referred to as chargers) can (sometimes) be set to 50A. Setting a 50A current limit would be fine. Setting a 50A forced current (sometimes an option, and then let the "12V" voltage vary) would be bad, very bad. I have also seen chargers with a 50A "engine start", but that's for vehicles with starter motors, which the Prius does not have. I don't think chargers in "engine start" can maintain the 50A for very long, probably just a few seconds.

 

that combination of chargers overcame the reluctance to come to life. I think that would be an important combo charger setup to share with other folks who are trying to revive a very dead prius.

 

just used the 255v ballast charger to bring voltage up. Used a 12v charger that has a "start" setting. Both were only on for the time to hit the power button and get everything going. Then I disconnected both chargers and took the car for a drive. No cooling fan required for that period of time. I have watched the ballast chargers in the past, they don't cause much heat buildup very fast. Yes, use cooling fan if you are going to use the big battery chargers to "condition" the battery.

Yes, what you said. only using the 12v charger in engine start mode for the time it took to hit the power button and have everything light up and hear the ICE get going.

 

So, in "engine start mode" the 12V charger could supply up to 50A for a few seconds and that got the car started, but a 12V battery will still not provide enough juice to get to READY? That would imply the car needs an abnormally high amount of current to start.

Is that all correct?

Normally it takes something over 20A for a second or two to READY and a 12V battery can provide that. It can probably provide 30A even and keep the voltage above 11V. Maybe not 40 A though and certainly not 50A, which would be over 1C on a 45Ah battery. That would drag the battery voltage down to 10V or lower and the computers are not happy in that range, so no READY.

This implies that there is an immense current drain somewhere in the 12V system, 10A or 20A or something like that above the normal draw. At least at startup, and probably after as well. Once the car is going the DC-DC converter can put out I don't recall the exact number, but something like 100A. So it can feed that beast. 10-20A is a lot of current to be mysteriously missing, let us all hope and pray that this is something like the rear defroster being always on, or the headlights always on, and not some short to ground. Because the latter could get very very hot. I would not drive this vehicle until that large current loss is accounted for.

I would be very curious what the voltage is on the 12V battery (or at the jump point) when the car tries to start - and fails. Press the POWER button with a foot on the gas while somebody else watches the voltage. How low does it go? (My guess is that the car is designed to "give up" after a few seconds. The battery voltage will take a while to return to its resting value, easily 5 minutes, although most of the way there in 2 or 3 minutes, that is normal.) If the OP has access to a clamp DC ammeter it would also be useful to know what the peak current drain from the battery at (failed) startup is. I guess that would actually be "near peak", because the multimeter will only be giving 3 values a second, or something like that, so it will likely miss the real peak. The same device can be applied to the lead from the 50A charger when it successfully starts the car. (Perhaps the charger has a display mode where it shows output current? Some do. That way the clamp ammeter wouldn't be needed.)