Headlights left on, 12v battery dies

[paulccullen]

Last year my wife parked and got out the passenger door. The headlights stayed on. When she came back the 12v battery was flat. And just yesterday I did something similar.

Yes, I know, you must close the driver's door *after* turning the car off in order to get the headlights to turn off (unless you manually turn off the headlight switch)

Is there a device I can install on the Prius that will ebable it to shut off the headlights after the ignition has been turned off after a minute (similar to other cars) ?

(seems like a simple relay-and-capacitor should do the trick)

Thanks!

[Tadashi]

This has actually happened to us twice with the last time draining the battery. It has not happened before. Usually I thought the light automatically shut off unless we had the power on. Maybe Coastal Tech can add it to their products.

[chuck_k]

This may sound harsh, but how about driving the car?

By driving the car, I mean be aware of traffic around you and the systems of the car at all times.

Maybe a checklist would help--something to glance at habitually as she leaves the car?

It's always best to turn the headlights off by the switch, for a couple of reasons. The automatic shutoff system is a failsafe, not intended to be used as a standard thing.

[qbee42]

You can use a time-delay relay, or even a standard relay, in series with the light switch. Wire the 12 volts from the accessory jack to the coil side of the relay. That way the lights can be on only when the Prius is powered up. When you turn off the Prius, the 12V from the accessory jack will go off, which in turn will shut off the light relay. I prefer solid state relays, but any type will do as long as it can handle the current.

Tom

[jamarimutt]

Turn them on and off using the switch. The advantage of leaving the lights on all the time is most likely marginal and turning them off will increase your mpgs.

[lmalchiodi]

OK, the dumb question of the day...

What happens when the 12v battery dies? Does the car not start at all?

[abq sfr]

<div class='quotetop'>QUOTE(LynneM @ Jul 16 2007, 09:48 AM) [snapback]479603[/snapback]</div>

OK, the dumb question of the day...

What happens when the 12v battery dies? Does the car not start at all?
[/b]

12v battery fires up the computer... no computer, no run. Also powers the keyless lock system, thus you have the little mechanical key in the fob.

[paulccullen]

<div class='quotetop'>QUOTE(LynneM @ Jul 16 2007, 08:48 AM) [snapback]479603[/snapback]</div>

OK, the dumb question of the day...

What happens when the 12v battery dies? Does the car not start at all? [/b]

Just like any other car, if the 12v battery dies, the car won't start and you need to get a jump (from a friend with jumper cables, or call AAA etc.)

Just like "abq sfr" says" If the battery is completely dead you'll need the mechanical key on the side of the fob to open the door and pop the hood.

If the battery is flat, but not completely dead, the dash lights go "haywire" and the car won't go into READY mode.

[Tadashi]

Yeah I just had that problem. My battery was dead enough to prvent start up but still allowed the locks and MFD to operate. I got the carziest messages and warning lights. It started freaking me out at first.

[zenMachine]

<div class='quotetop'>QUOTE(LynneM @ Jul 16 2007, 10:48 AM) [snapback]479603[/snapback]</div>

OK, the dumb question of the day...

What happens when the 12v battery dies? Does the car not start at all?
[/b]

In addition to what others have already said:

The rear hatch door won't open. Which means you can't get to the battery. Which means you must be able to access the post under the hood (see manual). Which means if you park in the garage head-first (like I did), you will need a pretty long jumper cable.

Also, the post under the hood only accepts the needle-nose type clamp since it sits in a very small well. Very difficult to get to and clamp on.