Completely Dead, Trickle Charge no luck

on the 12 volt check the black wire where it connects to the body for a loose connection and corrosion if it looks good remove the battery and get it tested at a parts store, if the battery is good start checking fuses under the dash to the left of the steering wheel and under the hood, fuse box is on the drivers side fender.. my money is the battery is shot, trickle chargers don't provide enough amps to fully charge a battery from dead.

 

Check it's voltage for starters, with the car off, with a digital volt meter. For a better assessment check it with a digital load tester, something like Solar BA5. Battery retailers and the the dealership will have a pro version of the latter, if you can get it jump started and over to them.

How old is the battery btw?

And what is the charger you're using?

 

welcome!
how old is the 12v?
you were fortunate to be able to open the hatch.

 

Many trickle chargers are used to maintain a charge, not to charge a dead battery. It's just not strong enough

 

make sure they put a charge on the new one before installation.

 

Prii are fussy bitches anything lower than 11 volts and they give you problems...

 

Unconnected the 12v reconnect and try it, if it's ded, it's ded, make sure you charge the new 12v before installing it.

 

Please heed the ** warnings below **.

Sounds like the battery is pretty much dead at this point. (age in years, cold temps, etc.)

Before you try a jump start, be sure to follow the basics below.

** Warning ** never jump start a Prius from another RUNNING vehicle.
** Warning ** never cross the cables, and make sure the polarity is correct.
** Warning ** only connect the cables to the Prius when in OFF mode.

I'm doubtful driving around afterwards would do much (at this point) except get you or the vehicle from point A to B, or to grab a new battery.

edit: included addition warning

 

I've seen that mentioned several times here, but is there anything particularly dangerous about this? I looked through my Owner's Manual, the section on jump-starting. There are several cautions, but nothing about this. To be fair: it wouldn't hurt, the Prius 12 volt requirements are light, and I doubt it would overtax the "donor" car if it wasn't running.

This link, for example, says the donor car should be running:

How To Jump Start A Car Battery The Right Way | Meineke

I appreciate there's arguments, that the Prius is special case, sensitive electronics and so on, but is there an credence to these?

 

Good question, it was mostly parroted (would hate for someone to have a costly mistake), but to be honest my first 12 volt jump was from a Honda Civic that "was running at idle" and no major/costly repairs appeared (at least that I am aware of). Could just be another way to save gas and the environment.

Of course it wouldn't surprise me if others have had different experiences.

Many have said (and yourself), the 12 volt requirements for the Prius are fairly low. Its said purpose being to turn on the vehicle (so to speak) and is not used to engage a Bendix or turn a starter/flywheel; but will power other options/accessories in the vehicle.

Now I need to edit my above post and include an additional warning to only jump the Prius when OFF, though that would also be parroted as I can't remember if mine was on or off when I jumped it or if any deleterious effects would result otherwise.

 

If the other car has pretty bad battery and relatively high powered alternator it can give voltage spike when jumped vehicle starts. It would do this with every car but Prius is more susceptible to damage because of small 12V battery at the back with thin cables and lots of sensitive electronics in the front.

And if the other vehicle is older type with less of electronics it can have all kinds of charging problems while still operating perfectly.

It’s super small change to get any problems because the other vehicle is running. But since Prius jump starts fine from turned off vehicle (even with longest and thinnest cables) why take that change?

 

No, no and yes......in that order.
Once a battery is drawn down that low, it's life is greatly diminished, no matter what happens next.

 

Yes.
You should NEVER connect the jumper cables while the donor car is running.......regardless of what kind of cars you are dealing with......because having it running GREATLY increases the potential damage if you should screw it up by shorting the clamps together OR by connecting them backwards.

If the donor car is something with a lot of sensitive electronics like a hybrid (but what recent model doesn't have a lot of electronics), the potential damage can be even higher.

 

I guess that makes sense on a couple of levels. Lower voltage difference with the alternator not running, and no moving parts. I saw someone drop a jumper cable clamp into a fan blade once.

 

congrats!

 

Change the remote battery, get a trickle charger and once a month trickle charge the 12v for a day, digital devices have funny ground loops, old digital devices with corroded grounds are even funnier