No start, battery dead?

If the 12v battery is reading 11.4volts, it should still be able to start the car. Although it's low and need charging, that may not be the reason for the Red Triangle. You should check your oil level first and then maybe read any codes the car has recorded

 

Best to not jump the vehicle (it may not need it), unless doing it properly. If someone messes up the jump, it could cost $$$$.

If the 12v was replaced in the last year or so, it should be covered under warranty. The shop will likely test it before replacement.

1. How many miles are on the vehicle?
2. How many miles per week are you driving?
3. When was the inverter coolant pump last replaced?
   
4. Have you already checked all of the fuses? (dome light, AM2, etc)

Since there are OBD2 codes (DTCs) to work with, can you please tell us more about the RToD incident and the 'no start' condition.

FYI : you're moderated until you reach five (5) postings

 

That checking mode has 2 ways to check. The accessory and the ignition. Whats it read in the ignition mode?

it died because your not driving it much anymore. be more concerned about killing the $$$$$ hybrid battery that's next. The prius G2 must be driven fairly often or it will not do well.

Scariest thing you can do to a g2 is jump start it. Do not ever connect the jump cables directly to the battery. use the front jump point inside the fuse box. Its under the red plastic cover. RED IS POSITIVE LEAD! Ground is the chassis bolt right above that box. You reverse polarity the jump and it will cause alot of damage.

Jump point has a vertical METAL tang bolted to it to attach your jump clamp. Look at it closely.

 

She should be even more concerned about getting BAD advice on a forum like this.
What all of a sudden triggered your recent campaign of spreading mis-information about non-use killing hybrid batteries ?

There is NO evidence that non-use for any reasonable period of time (months) will have any really bad impact on an otherwise healthy HV battery. NONE.

Please stop.

What you need is a battery TENDER, not a trickle charger. Two different things.
Available for about $30.

Not good to leave the car in READY mode and unattended. Too easy to steal a "running" car.

 

No, not even theoretically.

A trickle charger is designed to charge a nearly fully charged battery back up to full. While they will eventually charge a discharged battery they will take twice, if not three times, as long as 3 to 5 Amp charger and a 3 to 5 Amp charger can take 15 - 20 hours to charge a fully discharged battery.

You put a maintainer on a fully charged battery and it will keep it full.

What you want is a fully automatic multi-stage 3 - 5 Amp with an AGM setting. Once the battery is fully charged, these chargers become a maintainer. You attach this type of charger to the car whenever you are not driving it for 3 or more days.

These types of charges might be available from Lowes but are definitely available from Harbor Freight. Good brand names are Schumaker and CTEK.

I would return the trickle charger (1.5 Amp not 1.5 Volt I hope!) you bought and exchange it for a smart charger.

As far as the leaks go, this has been discussed a lot in these forums, most recently here: Common source of leak for water in 12v battery well? | Post #2

 

A Gen2 Prius 12v battery should last at LEAST two weeks w/o being drawn down from normal vehicle parking. However, if there have been additions to modifications to the electrical system (aftermarket radio, alarm, GPS etc), these non-Toyota loads can deplete the 12v much more quickly.

Maintainers should NEVER EVER be used, especially in a building. There are tons of documented reports of them causing fires, as most are unfused. They are also not designed to charge a battery, but work well for keeping your trolling motor battery healthy over the winter.

If you need to CHARGE a battery, get something designed to do so. I do not like the "automatic" electronic ones because if you have a really low battery, they won't even turn on Decent quality manual 12v battery chargers can be had from major retailers for about $30, well worth having.

The Hybrid Inverter charges the 12v battery, well more correctly supplies power to the 12v system in the car. If the 12v battery is low, it can take a L O N G time (miles/hours) for it to be recharged by the car due to the modest power available to do so. Again, a 12v battery charger is a good thing here.

 

Not all that important, just gives an idea of what to look for at certain mileages.

10-20 miles a week may not be enough to maintain a 12v battery, especially if you use the SKS feature.

185k would be quite a ride for an inverter coolant pump, most last around 100k before needing replacement. If you don't already know the dealer maintenance/recall history, run the VIN at : Track Your Service Records with Your Toyota Owners Account

Focus on the Dome fuse, and then the AM2 fuse which may blow when the above pump fails. Then go from there.

It may be the battery is low. When using a voltmeter, what is measured voltage at the jump points under the hood?

Don't buy a random OBD2 scanner, most aren't hybrid compatible. If you do purchase one, make sure the return policy is there.

If the measured voltage is low at the jump points under the hood, recheck all of the connections at the 12v battery. Some of the plugs may not be fully clipped in, and check the 12v negative ground strap where it bolts/attaches to the body for rust/corrosion.

Have you ever had an issue with with the dash going black? (failing combination meter)

tldr : If the 12v battery is measuring around 12v, and when using a voltmeter you can see a similar voltage under hood at the jump points, and the fuses are good, it should be starting.

 

NO, not the same.
A trickle charger has a more or less fixed charge rate and it continues to stuff that small amount of charging current into the battery whether it needs it or not. This can lead to overcharging and loss of fluid and battery damage over long periods......like weeks or months.
A "tender" type charger automatically cuts down the charge as the battery fills up.
Read the instructions for the one you got.
It probably is OK.

What a bunch of crap.
NOT TRUE at all.
That is exactly what they are designed for.
Literally tens of thousands of them get plugged in every winter and stay connected until spring.

Your totally wrong information is not helping anyone.

 

Sorry, don’t even read what he has written, not even going to spend time refuting his statements.

 

Buy at least a 7-10 amp selectable smart charger, does both maintain and charge. Some chargers have option to regulate output for AGM batteries, such as the Prius 12v.

Trickle charger is older technology if you could call it that, quite sure none are sold anymore.

Get this charger from Lowes. And the Obdii reader online to use with phone app, yours iPhone or Android?

 

battery nerdiness alert .. : a LA bat should be charged about 1/20 of capacity safely .. ie battery has 100 ah rating ...
bat charger should be no more than 5 amp rating .. because 5*20 is 100 ...

so if the tiny aux battery is only 30 ah rating .. then u wont be wanting to shove more than about 1.5 amp juice to it .. maybe 3 if an AGM can take it faster than an SLA LA .
Somebody can chime in on charge rate for AGM chemistry ?

 

SLOWER is ALWAYS better. There are those that claim higher amps does some kind of sulfate reversal, there is little supporting evidence that the theory works (chemistries of Pb batteries differ, therefore results as well). However, too much V or A will KILL most Pb types.

 

Did you read the specs for the Battery Tender charger? SELECTABLE

10 Amp, 6 Amp and 2 Amp Selectable Charges and Chemistry Maintains Charges Most 12V Battery Types

POWERING UP: When you first plug the charger into a power outlet, all of the LED’s and battery level lights will illuminate for about two (2) seconds. The charger is set to default to standard chemistry and 2 Amp mode.

BATTERY CHEMISTRY/POWER SUPPLY SELECT: To change the battery chemistry or select the power supply, a press the Chemistry PWR Supply button to scroll through the selections. This must be done before you connect to a battery. Once connected to a battery you cannot change the battery chemistry. To change the battery chemistry simply disconnect one (1) of the alligator clips.

Manual for Prius Optima YELLOWTOP Type: DS46B24R and Prius service manual for AGM battery

From the service manual

In most vehicle charging systems, the alternator limits the charging rate by limiting the output voltage (about 14.4V). For example, an AGM battery may be observed charging at 60A and 13.5V. As the battery recharges, the charging voltage will increase from 13.5V to approximately 14.4V (voltage will vary based on temperature, control sophistication, etc.), and the current will decrease from 60A to about OA. The charging system voltage regulators prevent both AGM and flooded lead acid batteries from being overcharged and venting. By controlling the voltage, the charging rate (current) can be controlled.

The discontinued Special Service Tool (SST) Automatic Trickle Charger (SST P/N 00002-YA122-01) maintained a manual charging limit of 10A to accomplish a safe recharge rate for AGM batteries. This low amp charge was low enough to prevent the AGM battery from overheating and venting since the charger had no way of monitoring battery temperature/condition.

 

That is OK to get a charger that big IF it also has a lower automatic range of 4 amps or less.
But for most people, spending the extra money really isn't a good investment.

You are absolutely wrong about trickle chargers not being available.
Just for instance, Harbor Freight has one for about $4.

It is really not that much different.
Not worth worrying about in a vehicle application.

 

WTH? You sell these things or something??? I realize you may not have authored the above, but it is either deliberately wrong or ignorantly so. Let's review, shall we?

That is so incredibly inaccurate, it is not even wrong. If you do not know why, me telling you will not help.

As before, but deferentially, automotive charge systems are designed for FLOODED batteries and their specific charge rates. Installing Gel, Dry or Lithium based batteries, even those marketed as being "12v" CANNOT be charged correctly. And again, if you do not know why, me telling you will not help.

 

Actually HE is providing much more useful information than YOU are.......since you are really providing NONE.

Any automotive battery that uses the same basic chemical structure as the original lead/acid design can safely and efficiently be charged by a system designed for a wet cell lead acid type. That includes AGM and Gel.
It will not be "perfect" but more than good enough.

The newer lithium or Iron or phosphorous designs might be somewhat different but my bet is that if they make them in a physical configuration that matches the original they will do just fine too.

Note: You really could do a more efficient job of saying "I am just going to be obstinate and not provide any useful information."