Prius Prime 12v dead, what to do after?

>> it has nothing to do with your traction battery charge <<

I'm able to toggle it on and off, but, in addition to the icon shown in the image, the car appears to be operating on the assumption that the traction battery is completely discharged... i.e. the engine runs constantly.

Gotta go... I have a communications rewiring job that begins after the office is empty and will report back after that... if I can get back ;-)

>> start with dead battery <<

In this case, I had replaced the battery. Assume I will get a replacement battery under warranty from Toyota next week, and the battery I just bought will be transferred to my wife's car when things are back on track.

>> battery cost <<

$99 + tax and core charge.

Later... perhaps the car will sort itself out to an from on this job... taking jumper cables in any case.

Beverly Howard

 

Thanks for sticking with me and the icon "toggle" tip... Would not have found it without a hint. Things seem to have sorted themselves out... it stayed in EV mode (no engine) out and back.

Thanks for everyone's help,
Beverly Howard

 

Hi Beverly, My Prius Prime Advanced was parked for 5 months and now the dashboard lits up but nothing is written or shown on the dashboard. I am curious to find out, was your issue completely solved by replacing the 12V battery. My friend has only used a small Li-Ion recharger tool for 5 minutes or so to try to recharge the 12V battery. I am assuming if I can jump start this car with his SUV, then it is a better option to charge the 12V. Any suggestions based on your experience, will be greatly appreciated.

 

yes, the 12v is dead. there is a constant drain on them, so they can't sit around too long without being driven.
depending on the charger, it will likely need to be left on over night, then a voltage test should be performed, both static and load, to judge the health of the battery.
if the car starts, that is not an indicator that the battery hasn't suffered irreperble damage, testing must be done.
if it doesn't pass a load test, or if the car will not start, replace the 12v.
be very careful if you try to jump it from another car or portable jumper. a reversed connection can severely damage the expensive inverter assembly.

 

Thanks Bisco.... we are trying to leave the trickle charger overnight, under the hood, will seei if it revives the battery....

 

It's pretty likely that overnight trickle charging will not be enough for a battery as dead as yours seems to be. Trickle charging could take days. But we can hope.

 

Can you clarify "trickle charger"? There tends to be a wide gamut of descriptions for that item here. If it's a smart charger, 3~4 amp range, the style that can be left on indefinitely, you should find out soon enough if your battery's viable. I suspect not though.

If I'm not mistaken you've got a thread on this, AND you've revived 4~5 threads, asking questions of posters from a year or two back to chime in on your current issue? Maybe just let it subside for a while? The people you're asking sometimes haven't kept up with the thread, leaving currently active members busy answering. Or ignoring.

 

To revive the thread... Indeed the e12V system on PP is independent from HV system unless.. the car is "on". I had numerous instances when my PP "died" and nee a jump start to get going...

BTW.

the worst case scenario I could imagine would be to have traction battery fully depleted at the same time 12V battery goes 'dead'...

would engine go on if jump-started? I hope so..

brgds
K

 

No. The engine is started by one of the big motor-generators which is powered by the traction battery. So, if the traction battery was truly dead the car wouldn't move. But remember that when the MID says 0% (actually --%), there's about 15% left in the traction battery.

But if you ran the traction battery down to --% and then left the car for something like 6 or 12 months, the traction battery might fade away to nothing. Normally, a lithium battery that discharges too far is dangerous to recharge and the charging systems won't allow it. I don't know what the Prime's charging system would do.

Ed

 

Toyota recommends running the traction battery to 0% before long term storage. I don't think 6 - 12 months would be a problem. Maybe a few years. The 12v battery can be a problem, but a jump start can usually fix that.

 

After my 12v went low I now carry one of these and put the 12v on a maintainer if I'm not going to drive it for a week.
Since I now carry a LiIon battery jump start booster I've not needed it for my Prime but I have jumped 2 cars with dead batteries in parking lots and it works nicely.

 

The charger for the attraction battery does not charge the 12 V battery

 

Must resist...

 

I assume you mean the "traction" battery.

Yes, it absolutely does charge the 12V but only while it's actively charging the traction battery. It does not charge as aggressively as the PiP, but it does do a trickle charge. Easy to observe with a multi meter. Once the traction battery is charged, it's a good idea to unplug because the car's charger talking to the EVSE cable will accelerate the drain on the 12V.