Saving setting in car while changing battery?

Try this
keeping settings when replacing 12 v battery: which booster battery to use? | PriusChat

 

A charger or small jump battery connected under the hood will save the settings. At 12 volts there is no shock risk.


The main problem is the positive battery terminal will remain at 12 volts even when disconnected from the battery.


If the terminal touches any of the body while disconnected but being supplied with 12 volts from the front of the car. One you will loose the settings anyway.

Two if your using a charger you will almost certainly blow it's fuse.


Three if your using a jump battery you could blow the high current fuse built into the battery terminal.

Four it also makes it dangerous because any tool used to fasten the positive battery terminal that comes into contact with bodywork will carry a high current giving the risk of burns. The reason why when changing a battery always undo the negative first and re connect last.

My suggestion if you intend doing it this way is to very carefully remove the positive terminal and fasten it inside a plastic bag or rubber glove.

John (Britprius)

 

Do yourself a big favor. If you have to ask how to do this your not ready to do this. This is the last car in the world you should muck around with chargers etc while changing out the battery. So easy to cause big $$$ damage to the Inverter on this car by inadvertent spark or surge. Concentrate on the battery swap.

Takes 30 seconds to reprogram the radio.

 

The Prius will keep its settings below 9V ( I checked, inadvertently), so you can use a very small 9V battery with clip leads to the jump points at the front of the car. There is too little current capacity in a 9V battery to do any harm. Have a helper do this as you disconnect the 12V battery. There is enough capacitance in the electronics to hold the voltage for a few seconds with no battery connected. Or, use a diode in series to isolate the 9V.

A battery charger puts out unknown voltage with no load, so it is not the way to go unless verified.

But indeed, it might take longer to get that together than to reprogram the radio and windows.

 

Hi- I just bought a NOCO GB20 for when I'm heading out and I accidentally didn't shut the trunk hard enough. I read the instructions and it said Do not use on anything but a lead-acid battery. Anyone one know which jump starter works with an 08 prius 12v?

 

Prius 12V battery is lead acid battery. Any jump starter pack that’s either 3 cell lithium (the new ones) or 12V lead acid (the old ones) work fine. And actually you could jump Prius with almost any battery that has the correct voltage you don’t need much current to start a Prius.