Left Reading Light On For 3 Days Straight

I've left it on overnight, but not for multiple days. If you are concerned and try this procedure to check your battery:
Toyota Prius 12 Volt Auxiliary Battery with install kit for 2004 - 11

I think it will start and drive normally for the most part even if the 12V battery is weak. Occasionally, you may see a MFD warning message saying something about the brake and parking on level ground when the voltage is low. I got this several times while I was parked and didn't think too much of it. Finally, I got the message while driving and I lost ICE power until I pulled over and restarted the car, which convinced me to research the problem and verify/replace the weak battery.

 

From the instructions I previously linked:

 

I believe the 12V battery in a Prius is a deep cycle battery that can better stand deep discharge cycles than a conventional starting battery.
Just fully recharge the battery as soon as possible and all should be well. Drive the car for an hour with minimum high drain accessories on should get it near full charge.

When weather / snow conditions are bad I park my gen 3 Prius (2010)for as much as two months with a small charger / maintainer / desulfator connected to the battery through the under hood boost start terminal in the fuse box.
The model I use is the BatteryMINDer brand sold by Northern tool company. This is a very good unit that will slowly recharge the battery, maintain it at full charge and remove any battery damaging sulfation caused by an accidental discharge like you had.

The BatteryMINDer is safe for all battery types including sealed and AGM types.
I have 4 of those units I use to maintain the batteries in my fleet of cars, pickups and farm equipment.
BatteryMINDer Charger/Maintainer/Desulfator — 1.3 Amp, 12 Volt, Model# 12117 | Battery Maintainers | Northern Tool + Equipment

 

My quote is still relevant. If you've driven your car for 30 minutes, your battery is fully charged regardless of whether you have the touchscreen.

 

I doubt those steps will work on a Gen 3 (2010-2011) Prius as the color LCD (aka MFD) is NOT standard on Gen 3s. You only get it if you have nav. Navless 2010-2011 Priuses don't have an Info button, AFAIK.

For those w/nav, I'm not sure those steps work. Hopefully someone w/a Gen 3 w/nav can confirm.

 

Not so dumb actually, could happen to anyone. For me the key statement is the one above, if it had enough energy to start the car I think it will be fine.

Discharging the battery once and a while doesn't hurt it, it's designed with that in mind. Running it completely down to the point you need a jump to get into the ready mode might shorten its life.

 

Well, the Prius battery DOES NOT "fully charge" after 30 min of driving. Unless it was almost fully charged when you started. A drained battery will take 4-8 hours of "ready" to fully charge.

If you have the car in "ready" for an hour each day it will return to a normal charge level after a few days to a week. I wouldn't worry too much about it unless you leave the car unused for days after this kind of "drain event".

As stated above, it still allows the car to go to "ready" so is probably just fine.

 

You are correct, our 2010 Nav-less models don't have the buttons and displays called out by this procedure.

And several resident experts have previously stated very clearly that 30 minutes is not enough to fully charge the battery.

 

If I am not mistaken, and speaking from memory, the rear dome light can be also left "ON", if so, take care after your child (or grandchild) played with it.

 

Does the light still work? If it works OK and looks OK it is OK. Interior light bulbs usually last the life of the car so don't worry about it. If it is burned out I think there may be instructions in the owner's manual for replacing the bulb.

If there really are signs of burning or melting I think you would need to find out what went wrong, you should be able to leave that light on indefinitely without those kinds of problems.

 

what exactly is the "reading light"? is it the same thing as the interior dome light?

http://kyoei-usa.com/blog/wp-content/uploads/2011/05/Prius_Luxer1_after.jpg

that is the dome light correct? and even if these are left on, they automatically shut off after 20 mins or so? or is the dome light the rear seat one?

or is the map light, the light that shines over the shifter? (if this is the reading/map light, how does one control this? i thought it was always automatically on when the car is on)