Car wouldn't start until jumped, flashed hybrid overheat warning briefly

What kind of starting device was used? For a 12V battery or did you charge the high-voltage battery?

If the 12V battery is discharged, the hybrid system will not turn on, and the high-voltage battery will not connect to start the motor-generator, which spins the internal combustion engine.

 

Thank you, you have clarified this.
12V is used to supply power to various ECUs and to check the readiness of the systems for high voltage connection.
If the 12V battery is discharged (for example, 9V instead of 12V), then the ECU systems may not work, which causes the lights on the instrument panel to blink. Also, high voltage will not be connected, the "Ready" sign on the instrument panel will not light up. The internal combustion engine will not start, no one will be able to spin the engine.

The jimper supplies 12V to the power supply system, the ECU checks for serviceability and high voltage is connected, the inverter converts the voltage of the high-voltage battery to power the motor-generator, which rotates the internal combustion engine. Also, the converted voltage from the high-voltage battery is supplied to the low-voltage network of 12V, which is maintained at about 14V during operation. At this time, the auxiliary battery can recharge if it is not completely dead.

 

When was the 12v battery last replaced?

It sounds like it is time for a new 12v battery.

 

An electronic load tester can determine its present Cold Cranking Amps (CCA) value, give a verdict on its viability. Most battery retailers have them these days and will test for free. Dealerships also have them but will likely charge 1/2 hour labour.

if you have a digital multimeter on hand you can at least do a simple voltage test, get some idea.

Addendum: cheap electronic load testers are for sale, anywhere between $50~100 USD. If i was shopping it'd probably be the Solar BA9, I've got it's predecessor, use to that make.

 

Many lithium jump starters won't work if the car's 12v battery is too low. Some of the better ones have a force start option that bypasses the voltage and polarity checks.

This would concern me. These cars are known for quick temperature warnings that go away as the light on the dash is monitoring a sensor on a rubber coolant line. If air is in the system because of a hg leak the light goes off when air is at the sensor.

Alternatively, the second inverter coolant system with reservoir on the drivers side can have a failing water pump.

I assume you checked the coolant reservoirs for level AND fluid movement once the car is warmed up (about ten minutes of driving). If the level is down or the movement is not there you could have a hg leak or one of two water pump failures.

 

The traction (high voltage) battery is used to start the engine. The (12-volt) auxiliary battery is used to start the car's systems.

The short version is that you shouldn't be jump-starting a Prius until you know a little more than someone who's used to "regular" cars (and you really, really shouldn't be jump-starting other cars with a Prius).

The auxiliary battery in a Prius is much smaller than a "normal" car. The one in your 2013 is buried under the rear cover near the right tail light. More importantly, it also doesn't have the large-sized wires going to it, because it doesn't need to run hundreds of amps to the car's starter. That makes it where you have to know a little bit about a Prius before you go "jump starting" one like it was a regular car. Especially with equipment that's made to jump-start regular cars.

When you jump-start a car with a dead battery, the battery initially absorbs a lot of the initial jumped current. This is why you sometimes have to "wait a little bit" before you can start the car. At that time, the dead battery is swallowing enough of the current being provided by the jumper cables (and their cable clamps) that there's not enough left over to crank the engine. This is also true, but for a lesser extent for a Prius with a drained-down auxiliary battery. If you use the terminal inside the fuse box, you're still cramming a bunch of current through the car's wiring connection with the auxiliary battery in the opposite corner of the car - which isn't sized to handle the kinds of current a tow truck operator's jump starting equipment can provide.

Once the car being jumped starts, the opposite thing can also happen. There's now two vehicles, with loads of battery capacity that are going to be equalizing voltages through the jumper connection. Two separate charging systems with about a hundred amps each dumping current into the drained-down batteries. Even "normal" cars can have problems blowing fusible links when jump-started. A Tow truck operator's equipment can probably pump a lot more current than a Prius can handle - causing the wiring (as well as other things in the 12V systems) to get overheated.

Car batteries also have several specs that people mix and mash together to mean several different things all at once. Few people mix up the voltage, but batteries are also rated in terms of their Cold Cranking Amps (CCA) as well as their capacity (Amp Hours).

The CCA is supposedly a measure of how much current a cold battery can provide to a "normal" car's starter to get the starter motor to crank the engine on a cold morning (the measurement is more complicated than that, which is why I said "supposedly a measure". The one in a Prius has around 370 Cold Cranking Amps, around 800 for a "regular" car.)

The capacity is how much total electrical energy a battery can provide in the long term (around 48 Amp Hours for your Prius, around 110 for a "regular" car). There's an Amps component as well as a time component to this, and people tend to just say "Amps" and that's just not it. A battery that has a capacity of 100 Amp-Hours can provide 1 Amp of current for 100 hours, or 10 Amps of current for 10 hours, or 100 Amps of current for 1 hour (once again, it's more complicated, but that's the basic gist of the measurement).

People routinely talk battery capacity, then give you the CCA number, or give you the capacity and say it's Amps (without the time component). Even people who really should know better (auto parts salesmen, mechanics, and tow truck operators).

Prii work differently when they start because they're hybrids, and tow truck operators usually don't know how those hybrid systems work. When you first step on the brake and push the Power button in a Prius, the auxiliary battery doesn't start the Prius. It energizes the Auxiliary systems. There are two big draws on those systems come to life, the power brakes and the power steering. Normal cars use the engine for those. Since a Prius regularly shuts down the engine while you're driving, the Prius uses the auxiliary 12V systems for those. Since you've got your foot on the brake pedal, the brake system energizing can pull down a weak auxiliary battery. You may not be turning the wheel, but there's also an initial draw when the power steering first gets energized. Combine that with all of the other auxiliary systems and computers energizing and that's when the auxiliary battery usually fails. If it survives the initial draw down, the High Voltage (traction) battery starts the engine through the hybrid system.

Failing batteries can still have near the normal voltage when nothing is drawing any significant power from them. It's when something needs some power is when they can't provide enough energy and the voltage drops off. Auto parts stores and auto battery shops have testers that pull a load off of the battery while measuring the voltage to test a car's battery (a Cold Cranking Amps type of test).

This all gives a Prius an unusual set of reactions to a dead (or worn-down) auxiliary battery. Once you get how the whole system works, those unusual reactions become clear and it's easy to see what's been going on. If your tow truck operator doesn't have much Prius experience or a real understanding of a the battery systems in a Prius, they can do a lot of damage with their oversized jump-starting equipment. You may have gotten off lucky that you only got a one-time warning from your car.

 

"Many lithium jump starters won't work if the car's 12v battery is too low. Some of the better ones have a force start option that bypasses the voltage and polarity checks."

Yikes I didn't know that. I have a lithium jumpstarter pack in all my cars. I'll have to check on the one in my Prius!

 

I've had limited success with those. Mainly because the charge on the built-in battery wore down between when I needed it and when I charged it last. That internal battery also wears down and needs to be replaced after a few years too. (It's sorry of like a UPS on a computer, it works all the way up until the power actually does go out, then there's nothing left of the internal battery.)

I've got a 6-Amp car battery charger that I've had since the 1980s that's gotten me through more than a few run-down batteries over the years. (It's old enough to have a 6/12V switch, and the only car I know of that used a 6 V battery was the original Volkswagon Beetle.). I've only had limited success with that one too. Car batteries really don't like to be run down too low. Once you've started having battery problems, charging them doesn't really bring them back. The charger just helps to diagnose the problem, and maybe get the car going one more time (after a few hours of charging). I do like it in that it's not going to overwhelm any car's electrical system. It's got some internal protection so if the battery is trying to draw more than 10 amps, the charger shuts down for a bit, and tries again. if a car's battery is really low, it'll keep trying for hours, which is enough to get even the flattest battery to start charging - that one more time.

 

If your talking about the jump point under the hood; one of the strut tower bolts would be fine and reachable with those short jumper wires.
I would recommend practice using it a few times to get familiar with using it. The new ones has decent system and connections checks.

 

All that means is your battery was at a much lower voltage than his system. Since your car ran and continues to run after the jump, no damage was done.

The reality was buried in Danno's electrical dissertation above, eg a badly discharged 12v battery (yours) has to FIRST charge up to 10.5v or better in a matter of seconds or minutes from his battery.

In fact, the Owners Manual is specific on the matter:



Toyota says hook up the cables and wait "5 minutes to recharge the battery of your vehicle". Recharge in this scenario means bring the combined 12v batteries up to a usable voltage.

Usually 15-30 seconds is enough because the discharged battery may be slightly low and not severely discharged.

Finally the front jump point can easily handle 100 amps continuous through its 6mm cable back to the hatch battery.

 

I agree on this point especially for a personal jump starter that will be rarely used.

The JNC660 has a lead acid battery inside rather than lithium. The manual for the 660 warns about overcharging which is not a concern with lithium jump packs because of lithium's better charge monitoring.

Lithium batteries are far superior when it comes to holding a charge for six months or a year. I routinely store my lithium pack in the car for over a year without serious discharge.

Second the lead acid jumper is large - which is fine for a tow truck driver but not great for a person who may want to store it under the seat. A Prius driver with a discharged battery can't open the hatch to access something big stored back there. However you can still get into a locked Prius with the physical key and manually open the hood.

Third, the industrial sized clamps of the JNC660 may be too big for easy use on the Prius under hood jump point.

Since you have ordered it, try out the clamps on your jump points and decide where you will keep it for easy access.

Any jump pack should be periodically charged. I use a recurring yearly calendar reminder on my phone. If it was a lead acid jump pack I would likely charge it every two months.

I use and recommend a Noco GB40 lithium jump pack which is small, the charge will last much longer and it has safety features for most situations and a bypass when you need it. It's the number one seller on Amazon at $99 for several very good reasons.

 

I've got a couple of old gel lead acid jumpers. Replaced both batteries twice already over the last two decades. They've got their own space in my garage, next to an outlet. They get tossed into my cars for road trips, after hitting the internal test button. One is usually good, since I have them on a charging rotation.
Locally, I can call for help.