Dead 12v Battery --- A Glove Box Remedy?

Saw just that exact thing on TV last night. Not sure if its Discovery or DIY but the show is "Cool Tools". Its a generator that sits on the ground with a little pedal protruding out the front that you repeatedly step on up & down like riding a bike and it turns an M/G. Puts out some really good juice they say enough to charge up a car's dead battery in no time. Pretty cool. I'll try and find a linky.

 

The charger in the original post jumps the battery through the cigarette lighter outlet.

I could be wrong here, but I thought that the Pruis powered it's outlets via the HV battery, not the little 12V battery. Plugging this item in doesn't appear as if it will help you start your vehicle.

Can anyone with the "know how" chime in here please? I like the idea of a small battery that can be charged monthly via the car outlet, and fit in the glove box the rest of the time.

Thanks in advance to the clever people.

 

I think you all are off your rocker with your odd solutions for a non-problem. If you are worried about your battery dieing, just keep a cheap pair of jumper cables in the trunk. This whole spare battery thing is way too much work. If you can't teach your wife how to use them.(OMG) Then just teach her how to use a phone to call for a jump. I know I am sounding sarcastic, but jeez, what is so difficult about a pair of jumper cables?

 

I agree totally. Also learn to close and lock doors, switch off lights etc.

 

But a flat tyre can occur any time any where, a flat battery is caused by carelessness or neglect.

If you are careful a flat battery is far less likely. Also near enough every car on the road has a supply of 12 volt electrons they can give you to start your car via jumper cables, and most people will help out, I doubt anyone will lend a stranger a spare tyre even if they happen to have one that fits. People who neglect their standard battery are going to neglect a spare battery also. They are most likely the same people who run out of fuel too.

I think the best glovebox solution to a problem that doesn't exist is a D size torch (flashlight) cut in half, extended with a length of PVC pipe to hold 9 D size Eveready Gold batteries with a 5 year shelf life and a couple of jump wires rigged onto it. This will put out 13.5 volts and should start a Prius. Chuck it in the boot and forget about it for 5 years. Cheap too.

 

No reason it couldn't be made with 3 tubes 3 cells each.
There is no rabies in Australia but I know what you mean.

 

I also like the D-Cell x 9 solution.

To make it more DIY, the cardboard tubes, some tape. Two tubes of Scott towels or five toilet paper ones.

To keep dead simple, we should plug this into the car Aux 12v port, instead of directly on the battery or under the hood.

Which one of the two sockets is always "live"?

It's cheap to buy the wire that has the big 12v plug and that ends with two wires, or just patch with regular wire into the existing 12v tire inflation compressor. Nothing to buy, and you want to have both anyways.

Should also be easy to test, right? Just unplug the red wire from the exiting battery in the rear of the car. Then plug in the air compressor/spliced in 9xD cells. All stuck together with gray duct tape for extra DIY goodness.


_

 

I have a 2001 model Prius and I recently had to get a new 12 volt battery due to accidently leaving a door ajar which caused it to run down even though the dome light was turned off.
What happened is evidently the instrument panel door ajar light bulb which draws 1 watt combined with other electrical drains ran the battery down enough to ruin it. These batteries use to cost about $300 I bought mine (non OEM) for about $100 and I also changed the stock incandescent bulb to a LED type.

I think the solution is if a after market company did a installation (that I hereafter refer to and Accessory) that included electrically tapping directly into the HV battery. The 12 volt battery's state of charge would be maintained by using a HV to 12 volt charger that wouldn't be on continuously because that would use to much power, so only when the 12 volt battery reached a certain voltage would it get charged. Note when the ignition is turned on then this Accessory would turn off. Also this Accessory could disconnect the 12 volt battery if it sensed the HV battery voltage was getting low as in a case of the headlights being left on. Another benefit is you could charge and or maintain the HV battery with power from an 120VAC electrical outlet. If this involved using a large charger then a special HV plug could be installed in the car so the charger wouldn't have to be.

 

Patsparks - D cells in series would not start my Prius. Probably a series parrallel setup (with more cells) would do it. A 6 or 7 amp-hour gel cell certainly does. They are about brick-sized.

Tapping into the HV battery opens up several interesting possibilities, some of which were mentioned by Rokeby. But besides the actual physical danger of it, the Prius HV system is extremely sensitive to tiny current leaks. If you cannot engineer your entry points perfectly, you are going to have system main relays opening up all the time. It would be a real pain.

Original 1998 Prius had a similar battery boost system, but that did not survive the model change.

 

When I swapped an Optima into my Prius, I checked how much current was drawn from that little battery when the Prius seemed to be sitting there doing nothing. And I was shocked. Leaving a door open, even if the lights go out, causes a substantial draw. Opening a door, and closing it again keeps the car "awake" for quite some time, drawing a significant current. In fact, I went through the trouble of sitting there in the car with my ammeter (without opening doors) for about 30 minutes before I got really bored - and the car never did go to sleep fully, and was drawing several hundred mA from the battery. I'm not sure just what it was doing with that energy, but I know it was being taken out of the battery!

And then I tested the SKS button. There is no significant difference with the button on or off - contrary to what I've heard mentioned many times on this forum. If somebody has taken measurements with the button on and off - and can quantify a difference, I'd love to hear about it. I'd also like to hear how long it takes the car to finally go to sleep - and what the current draw from the Aux battery is at that point. Once you open a door to check, everything wakes up, and you get a big reading.

 

Oh... and I meant to say: Why doesn't Toyota simply include a button to jump the Aux from the traction pack!? The EV1 was the only battery car that I've had that offered this. It is a no-brainer. Carry jumper cables? A spare battery? Why, when you have enough power to light up your house... but no access to it. Crazy.

 

You're 100% correct! My Prius had a hatch malfunction and it drained the 12 v. battery in about two day, because the switch was on!

 

One of the problems with a Prius is that if the 12 v. battery dies, you can't open the rear hatch, so the jumper cables are usless. The connection points are in the fuse box under the hood!

 

You can open the hatch when the battery is flat, further instructions in your glove box.

 

dit you lock your doors when sitting inside and using the amps meter?

only after 20min or so when the doors are locked the prius go's ins stat of sleep ( not realy sure )