Flattened My 12V Battery

[Jan&tone]

It doesn't bother me, it feels weird to me not to wear the seat belt, and I put it on even if I'm moving the car a short distance. When I was learning to drive, I always tried to do an emergency stop with the aim of getting the instructor or examiner to hit their head on the windscreen... I don't think I managed it, but I seem to recall I got pretty close (or maybe I like to think I got close).

when I took my test, the examiners used to hit the dashboard with the flat of their hand to signal the emergency stop. The idea was that us learners would try to hit their examiners head on the windscreen like you say, but i was lucky, I only broke his wrist! He slipped on the dashboard and his hand hit the windscreen - those Austin A40's didn't have much of a dashboard

[korat102]

I did that, didn't leave lights on though, just didn't use the car for a while but left everything connected. It ruined the Battery, the thing would hardly hold a charge for a week after I'd allowed it to completely discharge. I fitted an Optima Yellowtop which has a greater capacity and, it's hoped, won't go flat so quickly if left alone. I also bought a trickle charger which I can connect if necessary every few weeks. Fingers crossed, it's been fine since.

[timberwolf]

I did that, didn't leave lights on though, just didn't use the car for a while but left everything connected. It ruined the battery, the thing would hardly hold a charge for a week after I'd allowed it to completely discharge. I fitted an Optima Yellowtop which has a greater capacity and, it's hoped, won't go flat so quickly if left alone. I also bought a trickle charger which I can connect if necessary every few weeks. Fingers crossed, it's been fine since.

If it weren't for the occasional trickle charge I don't think my 12V Battery would have survived the 3 years that it has so far, and that included a six week gap in use at the beginning of this year, which has probably shortened its life span a bit more.

[korat102]

Oh, here's a little tip for all you users of modern cars with remote locking/unlocking. Make sure you use the manual locks occasionally - just unlock and/or lock the doors with the keys once in a while. If you never use those manual locks, they'll seize up and when you allow your Battery to go flat you'll have problems getting into your car to recharge the thing! Don't ask me how I know this...

[bribarb]

My 06 prius had a flat Battery 12v. You cannot get into the car. The mechanical key in the remote fob only operates the electric locks which is useless if the Battery is flat. Even if you do get in you have to crawl through to the back to open the tail gate so you can access the Battery. I have obtained a cigar plug to cigar plug cable so that I can trickle charge from another vehicle if it ever happens again.

[timberwolf]

My 06 prius had a flat battery 12v. You cannot get into the car. The mechanical key in the remote fob only operates the electric locks which is useless if the battery is flat. Even if you do get in you have to crawl through to the back to open the tail gate so you can access the battery. I have obtained a cigar plug to cigar plug cable so that I can trickle charge from another vehicle if it ever happens again.

The Mechanical key from the fob operates the drivers' door lock only, and it can apparently be difficult to turn.

Unfortunately, you've wasted your money on the cigar plug cable, I am pretty certain that the Aux power socket is only switched into circuit when the car has been switched on either Ready or an accessory mode.

[kithmo]

My 06 prius had a flat battery 12v. You cannot get into the car. The mechanical key in the remote fob only operates the electric locks which is useless if the battery is flat. Even if you do get in you have to crawl through to the back to open the tail gate so you can access the battery.

Nonsense, speaking from experience with SWMBO's 06 Gen 2 prius, the mechanical key unlocks the drivers door mechanically, the electric locks are for the central locking, probably your lock was seized.

I opened SWMBO's drivers door with the key, pulled the bonnet catch, then started the car via the jump point under the bonnet, with a portable jump starter, no need to access the Battery in the boot to get it going. Once its in ready mode, you can go open the boot and access the Battery if you must.

[kithmo]

Unfortunately, you've wasted your money on the cigar plug cable, I am pretty certain that the Aux power socket is only switched into circuit when the car has been switched on either Ready or an accessory mode.

+1, Correct, plus even if it was live and you tried to start the car through the power socket, it would blow the fuse, energising the relay to the HV Battery draws 30A momentarily.

[bribarb]

I forgot to say I had fitted a fused direct connection to the Battery in the boot.

I still cannot get the key to work as a mechanical key. It does make the electronic locks work.

[Chris Dance]

I had a flat Battery on my previous Gen 2 57 plate. Toyota Club used the RAC in those days. The RAC opened the drivers door using the key and then carried out the procedure kithmo has outlined. I do not think it wise to connect direct to the Battery!! Use the connecion on the right hand side of the engine compartment. Never had to climb in the back to open the boot this seems unnecessary.

[bribarb]

I did say it was a fused direct connection which I use for my other equipment.

I still cannot get the door to unlock with the key. Maybe it is seized?

What does the connection look like on the right hand side of the engine?

[Yolina]

I do not think it wise to connect direct to the battery!! Use the connecion on the right hand side of the engine compartment.

I don't see why connecting directly to the Battery would be an issue. The connection in the engine bay is probably there more for convenience than anything else. The Yaris hybrid, with the Battery under the rear seats, does not have a jump point in the engine bay - I would have preferred to have one tbh but I suspect it's probably easier to access the Battery in the Yaris than the Prius :). The owner's guide for the Yaris hybrid clearly shows jump starting by directly clamping to the 12v battery.

[ian rooke]

Hi one thing about using the key to open the drivers door to test if it is working and not seized, it will set the alarm off tried it got the T shirt.(Gen3)

[Chris Dance]

bribarb. The connection in the engine compartment is shown in the owners handbook. It is on the right hand side of the engine compartment underneath a black plastic cover. The handbook details the complete procedure to be carried out in the event there is a flat 12v Battery. I do now own a Gen 2 now but other Gen 2 owners should be able to give you the handbook page details. Hope this helps.

[korat102]

bribarb. The connection in the engine compartment is shown in the owners handbook. It is on the right hand side of the engine compartment underneath a black plastic cover. The handbook details the complete procedure to be carried out in the event there is a flat 12v Battery. I do now own a Gen 2 now but other Gen 2 owners should be able to give you the handbook page details. Hope this helps.

The handbook is worth a read, gives all sorts of dire warnings about push starting and info on jump starting. The section starts on page 276, diagram is on page 278. Pretty (though small) colour picture at http://prius-in-mk.b...at-battery.html. For info: the jumpstart terminal is inside the fusebox.

[kithmo]

The jump point is on your right as you look at the engine which is the left (passenger) side of the car.

I did say it was a fused direct connection which I use for my other equipment.

I still cannot get the door to unlock with the key. Maybe it is seized?

What does the connection look like on the right hand side of the engine?

As long as the fuse is at the 12v Battery end it should be OK.

The jump point is under the fuse box lid. Open the fuse box and you'll see a red plastic square with a "+" sign on it, it hinges open to your right, under there is the 12v jump point. Put your "+" lead on there and your "-" on an engine or body bolt to jump start.

I think your drivers door lock probably is seized. Squirt some WD40 in it and leave it overnight then try it.