2002 Prius won't start after sitting for one month

welcome!

you probably need to put a charger on it. it takes the car a long long time to charge the battery. if that doesn't work, tke it in for a warranty replacement.

 

It sounds like you have one problem, and also another problem.

The obvious problem is that the 12 V battery is deeply discharged. It might come back on a dedicated charger as bisco suggests. If it can't be resuscitated, a replacement is in order.

The other problem: there is some other issue with the car that caused it, on your first drive, to detect a problem, light the warning light, and drop out of READY.

This is where it gets complicated because of your first problem. You've got no juice in the 12 volt. Once you jump the car and get it to READY, that doesn't matter, because in READY, 12 volt power is coming from the DC/DC converter and not from the 12 volt battery. So the car seems happy. BUT, it detected something that made it show a warning and cancel READY. What happened the instant it canceled READY? Click ... woops ... hey, there's no juice in this 12 volt, is there? Hence the sudden total darkness.

That also means that whatever diagnostic code went with that warning light, and would tell you what that second problem was, is erased already. So that will remain a bit of a mystery until the 12 volt battery is either successfully returned to full charge, or replaced.

Then, if the other thing happens again, it will just cancel READY (it won't blackout the whole car), and the code(s) can be read to get the details.

-Chap

 

No vehicle likes running without a good 12v battery. Non-hybrids are apt to stall and set DTCs with a dead 12v battery.

I would choose the simple route first - replace 12v battery and retest. No matter what the end may require, that will need to be done first.

 

EVERY car owner who lets his vehicles sit for long periods unused needs a small automatic tender-type battery charger.
This is especially important for hybrid owners because of the smaller than "normal" 12 V battery.
That does NOT mean a cheap trickle charger.

If you can't leave a tender on it all the time, connect it for as long as possible once a week or so.

Letting batteries go completely dead and sit like that GREATLY diminishes their life span.

NOW......connecting a small charger for maybe 36 hours might bring it back to life but you shouldn't count on it lasting long.

Searching the forum is a good thing to do. This has been discussed before, in various forms, maybe a hundred times.

 

Oh, you must be my sister! This sounds so like me! Letting the car sit for long periods of time runs down the 12-volt battery. Sounds like your 12-volt is not getting adequately recharged. Also keep in mind your battery cables should be connected tightly so that it is recharging properly when driving! (I've kept my negative cable a bit loose for ease of detachment which for ease of use for a Booster pack jump! That's a big no-no I've recently learned and has caused me more battery problems!) I would replace the 12-volt entirely or take it somewhere that you can guarantee you have a FULL charge at a local filling station that does minor work. No sense in taking it to a place that's gonna charge you gobs of $$$ for something simple. If a fully charged battery or new battery doesn't resolve issue, then there are issues which must be explored. An R26-3 battery will fit the OEM if you remove stabilizer bar. It works for me and I've had no issues. $66 at Walmart.

Best of luck to you!

 

I can't think of one filling station that still does work. The national chain auto parts stores will charge and load test your battery if you can bring it in. Your 2 year old battery from Toyota may still have warranty on it & they'll replace it on a pro rated basis--maybe a few bucks off the dealer price.

The battery Sandy suggests WILL work. And it is a lot cheaper. Has a coupla features I wouldn't suggest tho. It's a wet cell instead of an AGM so when it tips over or springs a leak it will, it will spill concentrated sulfuric acid & cause bad corrosion in the fender well. Also when it's charging, it vents hydrogen gas into the trunk and potentially into the passenger compartment. That stuff is highly explosive--think of the Hindenberg zeppelin. Probably wouldn't get concentrated, but might. Finally, Toyota spec'd a deep cycle battery (because it maintains the memories of electronics, the radio, and the clock) and the one from Walmart is just a plain automotive starting battery. The 12v battery only operates the computers and valve solenoids, it doesn't actually crank the engine.

Whatever you do, DO get a battery tender if you're going to leave the car for more than a few days. Leave it plugged in to maintain the charge of the battery long term. And, if you need to park the car at like a airport, you can do as Sandy suggests and disconnect the negative battery lead.

The Optima that Amazon sells will work, but it has the smaller Japanese style battery posts and the larger American style leads will not work (don't ask how I know this.) And the positions of the posts are nice person backward--which makes it difficult to position the battery in the battery well. While Amazon says it will fit, it's at best a poor fit. Elearnaid.com has a very nice writeup and sells a complete kit with the correct Optima battery.

 

"Is the hybrid battery dead or dying?" Could be. Tired cells won't hold as much charge as ones that are still good. And there are no good solutions. A shop that specializes in Hybrids could tell you definitively, even tell you which and how many weak cells you have. The reason I say no good solutions is that 'most anything you do is going to require a lot of massaging with $100 bills. Dorman re manufactures Gen 1 batteries--but there are no sources for new Gen 1 cells so the battery components are probably at least 15 years old. Cost is about $1500 plus installation. Toyota will sell a new hybrid battery for a bit more than $1900 plus installation with new cells and a 1 or 2 year warranty (2 years if you pay them to install.) Core is $1300, btw. Or you can have the bad cells replaced--problems are the same as going with a Dorman re manufactured battery. When the time comes, I'll turn my head and cough, and order the Toyota battery (Camelback in Phoenix has them for right at $1900.)

The reason I suggest taking it to a Hybrid shop (or at least a Toyota specialist) is that real and true diagnosis of battery problems requires specialized equipment and computer program.

 

and a 1 or 3 year warranty (3 years if you pay them to install.)

 

The local Toyota dealer here (Tucson AZ) quoted me a 2 year warranty. Might it be different in NZ?

 

Both of his bits of advice are way wide of the mark:

1. Jumpstarting and letting it idle for a few minutes does next to nothing.
2. Ditto for driving it once or twice a month. The latter pretty much guarantees a dead battery, lol.

If your use of the car is infrequent, and/or it's going to sit for protracted time, you will need to regularly use smart charger, something in the 3~4 amp range, capable of running a charging regiment, and also able to be left on indefinitely, as a maintainer. This will preserve the battery.

I've used a CTEK 3300 in that capacity for over a decade now, very simple and reliable. I recently acquired a (similar) CTEK 4.3, has a bit more amperage, a few more features. But the 3300 is good, still available I think.

Our current situation: the car frequently sits for a day or two, sometimes three, without use. If the car is being used daily, I leave well enough alone. But if it's for sure going to be an idle day: I'll hook up the charger, let it run it's regimen (will take 4~6 hours), then just leave it hooked up, till the next time we use the car.

 

I was meaning in the US, your dealer is incorrect, as it seems so many do not know what the warranty on Toyota installed batteries is. And you could well be right, it might be different in NZ.

 

Since your "mechanic" has given you some other BAD advice, their "test" of the 12 V battery might not be good either.
Given the relatively small cost of a new 12 V battery, I definitely advise changing that out first.

And then if that fixes the problem, you need to get a small automatic charger to keep it from failing again........to be used when the car has light or intermittent use.

If a new, fully charged 12 V battery does not fix the problem, it probably is time to start looking for a different car.
Investing ~ $3000 into a 15 year old car often is NOT a wise thing to do.

 

You are correct. The dealer guy didn't know this.

 

Aux batt had been taking more and more time to boot up control mod and finally stopped. Researched batt for a week , finally found one at Toyota. When the time came to install< I jumped started the car as per instructions for the first time in 15 years. Fired right up. Off i drove to pick up the batt at the dealer. Left car running , went in picked up batt and went to NTB shop to install. Removed old batt and discovered batt from dealer was wrong, called dealer and he was nice enough to deliver to shop about 4 blocks away. installed batt, backed out of bay into parking space. thank the shop friend and started the car to leave and car would not accelerate and died in about 7-10 seconds. numerous attemps to start and leave ultimately lead to the main batt drain. towed to Toyota and MaMech said main batts below 5% can not be reharged. Also said gas motor is done......Is my car finished after spending $300.00 to replace the aux batt so I could/can start it. I've owned her since the begining, 70miles on it and it jumped perfectly that morning and drove for about an hour with out issue. Acted like there was some protocal for resetting system after changing the batt........ANY IDEAS
325,000 Miles and looks brand new.

 

Some of have working clones of Techstream and can look at the condition of the individual cells. I also have the Prolong (Hybrid Automotive) battery reconditioning system. It can attempt to recharge your HV battery. Generally the mechanic is correct about recovering a totally dead HV battery tho I don't know what the situation is in your neck of the woods, but I would definitely want to get a second opinion.

What does the battery gauge on the upper dash screen indicate? Did you also run the aux battery (the one in the trunk) down? Have you tried jumping that one or hooking it up to a charger?


As for the IC being toast, did he say what lead him to that conclusion. Dead IC's on our Pri's seem to be almost unheard of. But it may be that your little car is circling the drain.

Wish you'd checked in here first. A regular car battery and jumper cables can be used on the aux battery to start the car. & you really did get hosed by Toyota on the $300 charge.

 

I did jump the call with cables in the morning and it drove perfectly.
The Toyota tech said if the hybrid batt is below 5% they are not allowed to even hook it to a charger.
Car was in good running order , just needed a aux batt to start it....Cant imagine what went wrong. I appreciate any thoughts...

 

Take it out and drive it enough to charge all the batteries, both the HV and the aux in the trunk. Bring it home, shut it off, restart. Try to start it in the morning, again. Could be the aux is defective or you could have something drawing it down. Be sure the dome lite is set in an off position. How many bars on the indicator on the upper dash screen?

& look for an independent hybrid shop.

 

Things usually work fine......right up to the second that they fail.

I think "what went wrong" is that it is a 15 year old vehicle with over 300K miles.
A really LOT of things could have failed, including what the dealer told you.