Battery dead after returning from long trip

Yep, there's a 12 volt battery that handles all that stuff plus more. Yes you can jump it or charge it with a battery charger. The instructions should be in the manual. (it's starts page 695 in the 2017 owners manual)

 

the 12v is under the hood. you can open the drivers door with the mechanical key in the fob, if it is locked.

triple a shouldn't have any problem, they have a jump pack to boost the battery.

my biggest concern would be its future health. i would buy a volt meter and monitor it for awhile, and a battery maintainer for your next trip.
you can also shut off sks with the fob, or disconnect the 12v neg.

 

But......the question remains:
IF he really left it plugged in during that time, why would the 12 V battery be dead ?

Unless maybe the "fickle finger of fate" just made it fail despite being charged.
Or does the Prime NOT do anything for the 12 V while plugged in ??

 

Maybe leaving the hybrid battery charging cable connected accelerates 12 volt charge depletion? Page 88 of the 2017 Prime Owner's Manual:



For diagnosis, something like Solar BA9 will do it, or jumpstart and go to an automotive retailer with testers.

For next time, hooking up a smart charger, something like CTEK 4.3, will preserve the 12 volt charge. It can be left on indefinitely.

 

Thanks for updating your experience. Good to know that PRIME jumping is easy to perform. I purchased portable lithium battery jump starter just in case like this, but have not had an opportunity to use it yet.

 

I think you should SERIOUSLY consider spending ~$30 on a good tender-type battery maintainer.
Getting the battery FULLY charged again is important......and you can't trust the onboard system to do that.
And you can't tell if it IS fully charged without a multi-meter (another good piece of equipment to have.)

 

Yes, 12v battery drain is a common issue with most cars nowadays when left undriven for a while.

That is why I always add a battery trickle charger to every hybrid or EV I bought in the last 15 years. I do this on day 1, all the time and my 12V batteries stay consistently healthy and always lasting longer than 5 years. Since I travel a fair bit now and then, this is the best $100 mod I make to each car.

Below is a picture of my 2018 Prime's engine bay. As it is, the battery trickle charger shares the plug with the block heater which is a bonus during the coldest days in winter (-40 and below):



If I recall correctly, the on-board charger located under the rear passenger seat does indeed provide (output @ ~14V) power to the 12V sub-system. However, this only works when the battery pack is being actively charged and thus stops when the charge event is complete. If this is indeed the case, then any charge it provides to the 12V accessories battery is modest, brief and insufficient especially if you leave your car plugged to the L2 EVSE when you are away for more than a few days.

Caution: I only have the trickle charger plugged in when the L2 cable is disconnected. Better safe than sorry.

Cheers

 

Two things about that:

I hope you are using "smart" automatic tender type chargers and NOT a dumb trickle charger. The difference is important.
It is also important that you describe the equipment properly.
You should NOT be recommending trickle chargers.

Then.....plugging in a tender every night is just wasted effort in most cases.
You can't charge a battery to more than 100% and there is no point in trying.

Note: In the winter when it is REALLY cold might be an exception but cold won't hurt a healthy battery either.

 

As you've discovered the hard way, the Prime (and the PiP) only trickle charge the 12V while actually charging the traction battery. When not charging the traction battery, there is no power going from the EVSE to the car's charger, so nothing available for the 12V. As with just about any car, if you leave it parked for more than a few weeks, it's best to either disconnect the 12V or put it on a trickle charger. Turning off the SKS helps, but there's more stuff drawing power than just that.

 

Worry not. But have a careful look at mine in the picture. (it's actually a "Genius" and definitely not dumb)

LOL... I could not help it !!!

Anyhow, this one is quite good and able to detect and charge different chemistries with proper charge rates while also factoring temperatures. I recommend it quite often.

 

My $20 dollar solar solution...

If parked outside, this would have taken care of you.


Rob43

 

Would you mind giving details about the block heater. I still have the old one from my 14 PIP but haven't been able to source the primes part # down here is the lower 50.

In the winter I also use a small 120v adjustable wattage space heater in the cabin while charging to assist the onboard traction pack heaters. I run a duct taped 3 wire flat pigtail under the rear door and connect my extension cord to a different circuit than the EVSE. The space heater also doubles as a cabin heater and assists preconditioning as well and makes clearing windows of snow and ice much easier until temps drop extremely low.

 

Sure. The block heater in the 2020 Canadian models is now mandatory (I just bought one, they were optional for 2018 models). It's listed for $320 CAD and can also be ordered from most Toyota dealers in my area.

Build Your Toyota Prius Prime - Toyota Canada


The interesting thing about the newer block heaters: Their observed power rating is approximately half (220-240 watts) of that in the previous gen's block heaters which tended have a ~400 Watts footprint. Makes me wonder about their effectiveness after the latest Toyota recall for this part.

In my case, I've used the block heater on the 2018 only once last winter mostly because I knew I was doing a longer trip that day and was going to need the ICE. However, no matter how low the ambient temps are, the ICE never fires during my normal commutes around the city.

I too use a small electric heater (200watts) to keep the cabin warm while the car is parked at a public parking spot. It does the job pretty well and also keeps the battery pack happy and the EV range up.



So instead of having the block heater on, I simply condition the passenger cabin with approximately the same power the block heater would use. At home, I pre-condition the cabin before leaving in the morning. Of course, the heated seat and heated steering wheel use is a given every winter day.

Yeah, window fogging is a still a problem and while the space heater does help alot it does not totally prevent it.


Overall, it works fairly well for me.

 

Few questions.

What is the ambient temperature when you observed this behavior? Is it with the climate control ON? In my experience, if the temperature dropped to single-digit F (lower than minus 12C), my car started ICE regardless of the climate control setting. If climate control is set to ON, the ICE would come on at or around 14F (minus 10C). I could not prevent this with my car during winter and it made me decide not to charge at all during last Feb when the gas price got ridiculously low.

What is the source of power for the small electric heater? Do you have 120v plug at public parking? Can you put it on a timer?

 

@MSantos, $320 must be installed price, in your locale? The part price is around $90.

Interesting that they've dropped the wattage.

Mine (purchased November 2010) just fritzed out, wires shorted right at the unit. We used it A LOT, year 'round, for pretty much every cold start.

When I pulled the old one out I saw NO evidence of heat transfer grease. Either it had vapourised, or was never applied?

Dealership is going to give me free replacement part, and wants the old one, for Toyota to inspect.

Good to hear you posting btw.

Block heater failed | PriusChat

 

Great. But is is NOT a "trickle charger".

 

Any temp below 0C (freezing). I usually set the temp control to the "LO" setting and the climate control is usually OFF. To defog the windows I direct the airflow to the windscreen and then add one or two pips of fan speed. Rear defogger is OK, front defrost feature is not. Again, with a warm passenger cabin, I can do my commute in relative comfort even in the coldest days.

Yes, every public parking spot has a 110V outlet for block heater use. A rather common thing in Winterpeg.

 

The smart chargers will typically run through a multiple stage charge process, then fall back to monitoring and an occasional tick of charging. All the efficacy of a trickle charger, and safer.

I recall hearing they cycle the power on and off, alternate 1/2 hours? Is that the norm?