My 2020 RAV4 Hybrid regrettably sat for about 6 months and now its completely dead. I've tried to jump start it and no lights come on the dash, the doors won't unlock, and obviously the car doesn't start. The red light with a car and a lock occasionally flash. Any ideas? If I can get the trunk open and replace the 12v battery, would that allow me to start it?
Battery dead and can't jump start
Ben83
41 - 60 of 165 Posts
I think I saw that link when I searched and assumed it wouldn't be right because it wasn't a Toyota domain. I guess I've never noted that TSBs were hosted by the NHTSA.
I don't have time to look right now but I think Mar has a 2023. this was posted earlier than that so not sure if it applies....
okay, I think this is the right one: https://static.nhtsa.gov/odi/tsbs/2022/MC-10227923-9999.pdf
same deal, they say to start it up every 2 months for the HV battery. obviously this is probably somewhat conservative but it at least puts a lower limit on how long you can leave the vehicle without starting it up. the fact that this seems to make no differentiation between the different HV batteries is a little strange. for instance, we know the prime holds more charge so might that not be able to sit a little longer than the regular hybrid???
Joined
·
718 Posts
I suspect the op has most likely seen the discussion, got the information they were after but has chosen to not reply for whatever reason.
This may be an ignorant response and, if so, I apologize. I understand the positive post in the fusebox under the hood has a contact on only one side. I also belive that a number of jump starters have a contact on only one side of the positive clamp. So, if the engine does not seem to respond to the jump starter, rotate the positive clamp 180-degrees and try again.
Joined
·
718 Posts
Thank you for the above and earlier link. They are both very useful and informative.
I notice a couple of significant points for long term storage from the 2 links.
1. Disconnect the -ve terminal on the 12v battery for long term storage to eliminate parasitic draining. Reconnection will require some reinitialisaion of some functions - clock et al.
2. Put the car in P mode and not engage the electric park brake or its auto function.
3. Start the car after 2 months and idle the ice for 30 minutes to charge both the traction and 12v batteries.
I assume the 2 months in point 3 has a buffer to when the traction battery would have insufficient charge to enable the hybrid system to reach Ready state when the Start button was pressed. I'm not sure if the buffer extends out to 6 months even if the traction battery was at 6 bars when the car was put in storage.
Joined
·
718 Posts
That's a logical query/assumption but I then wonder if maybe the prime's HV battery with its larger charge capacity self discharges at a higher rate than the regular hybrid?
no idea. I'm def not an expert but assuming it's just "more cells" I'm assuming they discharge at a similar rate but the total number of cells being greater allows for each cell to need a little less juice to turn the engine over and get things charging.
Joined
·
718 Posts
You're probably right but the take-away for me from this thread is that we should be able to safely leave a rav4 untouched for 2 months and maybe will need to charge the 12v battery to be able to start the hybrid system when we return.
Leaving a rav4 untouched for 6 months, as in the op's situation, then being able to restart the hybrid really depends on the soc of the traction battery at the start, its physical condition and age, the ambient temperature and the mood of the "battery gods" when you return.
Thanks, CoffeeBear, everyone. My apologies for all the inquiries—probably more than the OP. I'm currently overseas, so I’ll find out what type of hybrid battery I have and whether the car starts when I return. I’ll share my experience here eventually. 😎We are trying to help Mar now
Joined
·
164 Posts
We don't have any real data.
Anecdotally I had a 2nd gen prius with a nimh battery. Battery booster broke and it sat in the parking lot. 12v went dead and I jumped it, but couldn't drive it without brakes so it charged the hybrid battery to like 3/8 bars and that was it. Over a few months 12v went dead again. Sat there for at least 3 months. I finally figured out how to get into it without power and recharged the 12v and started it.
So it was a generation of nimh battery who's lifespan was less than the current ones. Over 10 years old in use. Always parked outside. Minimum level of charge when the 12v died.
It still started right up and began charging. When I did end up junking it the guy drove it right over to the tow truck (using the emergency brake) without issue.
So my guess is the big hybrid battery in the rav4 - which is better made than the 2nd gen prius - is probably nothing to worry about even if you're snowbirding and gone for 6 months in a row.
Lithium and NiMH chemistries have different management protocols from what i’ve read. Lithium batteries can charge and discharge faster, and are more tolerant of being repeatedly run into a low and a high SOC. Because of this, the lithium battery is of a smaller overall capacity but operates over a larger SOC range, giving the same effective capacity.
I often have my NiMH battery showing eight bars when going down grades longer than a couple of miles, and have also discharged it down to one bar by repeatedly doing full throttle accelerations from 60 to about 90 MPH and then repeating as soon as the Rav slows back down.
Joined
·
686 Posts
Big difference here. Prime is using Li-on that does not discharge by itself very easily while Hybrid is using Nimh that discharges by itself.
Toyota does not run the traction batteries between 0 and 100%. When the gauge bars are empty, there is about 30% charge in the battery, and when the gauge is full, the battery is around 80% full. That's how Toyota get such a long battery life, they set the battery 0% and 100% limits to be about half of the batteries full potential. So if you park the car even at indicated 0% traction battery, it has enough juice to start the car. I haven't heard of anyone not being able to start a hybrid after parking it for a long time, except for a dead 12V battery which I have had in my Rav4 Hybrid. Don't overthink it. I assume the scanner is reading what Toyota says the battery level is, not the true SOC. I have considered getting a solar panel to put on the dash to keep the 12V battery topped up as I do sometimes leave my car for months at a time, and will be doing so in a few weeks, going overseas for 2 months.
Joined
·
64 Posts
A battery sitting in the cold will last longer than a battery in a hot location. The cold slows down the chemical reaction, of course you need more energy to start a car if it is cold outside but keeping the battery cold is good if you are not using it. I used to keep all my small batteries for smoke detectors, flashlights, etc in the refrigerator until my wife make me take them out.
Joined
·
718 Posts
I know the hybrid battery is not run between 0% and 100% and the reason for it but where are you getting the numbers saying that 0 bars is not 0% soc on the battery and 8 bars is around 80% soc?
Why is it not possible in your opinion that 3 bars is around 40% and 6 bars is around 80% ?
Joined
·
718 Posts
It depends on who you listen to because other people have said that both battery types will self discharge over time but the NiMH self discharges faster.
But I doubt the difference in discharge rates is large because the linked Toyota documents in this thread show Toyota suggest for long term storage that vehicles with both types of batteries are started after 2 months standing idle and run for 30 minutes to charge their traction batteries.
Joined
·
1 Posts
If you can access the 12v battery then slow charge it over the night. But it the 12v battery voltage is really low then often many new chargers will not charge such a very low 12v battery.... because of the newer electronics in them. It happened to me once like that on a regular ice car that was not used for some time. The work around that i used was that i also had an old heavy duty Craftsman charger that didn't have the newer electronics, and that kind of charger was able to put a full charge on that 12v battery. But if you are going to use one if those old version heavy duty chargers then i would first physically remove the battery,...or.... disconnect the cables to the positive and negative battery terminals (use a 10mm socket or 10mm wrench). Do that before charging it with one of those heavy duty chargers . Reason Is less chance of affecting any other electronics in the SUV. And finally, avoid jump starting the battery, again to avoid high voltage charges that can cause possible expensive electrical damage, especially in these complicated hybrid systems. But to avoid similar 12v battery discharging in the future, before going away, disconnect the negative battery post. Reason is...power is always powering the cars computer systems at a low but constant drain. That is why when you walk up with your remote the computer system can still be alive enough to react to you.
I believe Toyota updates that T-SB every near to cover the new models. I just cited the one that I have in my files.
Some hybrids, like mine, have a lithium battery. They are not all Nimh.
All good. Just making sure nothing had changed.
Joined
·
23 Posts
I have to leave my Prime for 3 months on its own when must travel out of the country. It stays in an Apartment building garage where I can't plug in a battery maintainer - not allowed + no electric outlets. If I disconnect 12V battery, how can I lock & unlock the car leaving & coming back? Or even better can I use the huge EV (drive) battery to feed a battery maintainer for the little 12V battery?
41 - 60 of 165 Posts
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
