Faulty 12 volt battery + possibly nuked electricals

HI Sarge , after reading your post , I am wondering more and more about the utility of the ACCESSORY mode in a PHEV. This mode had it's reason on a ICE only car...but on a prime I don't quite understand it's existence.......i must be missing something

 

This. From everything I've been told ACC mode on the Prime is pretty much useless and shouldn't be used. Whenever I'm parked for any length of time and sitting in the car, it's in Ready state.

Those of you with 12V battery issues, is your key close to the car when not in use? I keep mine in a old ammo can that blocks any signals between the car and fob.

 

I would encourage you to not start with the lawyer bit. You and maybe someone older should go in and talk to the Service Manager first. Take a notebook with an outline of the events. Calmly review those events. He will likely say nothing and let you talk until you are tired. Make the story clear and concise. Don’t fall for the smiling stall tactics.

Write down his comments in a serious but respectful manner. Be firm that you 100% believe the car is damaged beyond the battery and want it diagnosed fully and immediately.

When that fails, tell the Service Manager you need to talk to the General Manager. I assure you the GM knows nothing about this.

When he is not available ask for his phone number and leave a short detailed message. Writing notes the whole way. Names of everyone.

Then call Toyota Corporate and complain that you went through channels without results. They will contact the dealer and things will happen. Corporate will replace every ecu in the car if necessary once they get the picture.

There is a slight possibility the dealer is trying to fix the car behind the scenes but they are more likely trying to blame the tow driver’s company hoping to have that company pay. The dealers mechanic knows the damage. Service advisors are not mechanics and are really just commissioned salesmen. They can’t help.

 

It exists on the hybrid for the same reason as ICE cars; to access features without turning on the engine. The Prime is a variant of the hybrid. Removing ACC mode would have an actual money cost to Toyota, and while the need for ACC mode is less, it isn't completely gone.

Even ICE cars can quickly drain the 12V while in ACC today.

 

I think there was a thread about it and gen 5 was the same H4 battery? It has the vent hole, but not used on the gen 4 since it’s under the hood. Oreilly, etc have the H4 size too. Surely a Toyota dealer can get their brand next day. Mine for gen 4 is an Oreilly and has the vent hole with a plug in it.
This “problem” started with the first Prius decades ago, and other makes. The problem is it is different and the owners think it’s the same as an alternator car which keeps the battery up faster. Plus these batteries are smaller so have less capacity which compounds the problem.
Lastly, ask your dealer if it has a lojack gps tracker running on it. It should be in the original equipment list as a dealer installed accessory.

 

Hummm ....the prime defaults to EV when turned on .As I see it, the only time it will turn the engine on, it is when it is very very cold outside or that the traction battery is very very low , in both cases using the accessory mode is looking for trouble in those conditions . As for removing ACC mode would cost money to Toyota ....you could be right

 

Which is why I said the need is less. I was warned about using ACC mode in an ICE car because of the power drain. Accessories have been bigger power drains over time. Then hybrids and plug ins tend to have lower capacity starter batteries as they don't need them to turn over an engine.

There could also be legacy regulations that mandate ACC mode. Pre-OBD II, the mode may have been needed for diagnostics.

 

Interesting hypothesis
Thanks

 

College Towing ? Are you in San Luis Obispo ?

 

From my research, the Gen 5 Prius battery is NOT a special battery at all. In fact, it's essentially the same battery in the Gen 4. I just checked mine and it's a Yuasa 345LN1-MF. That is a flooded, lead acid 12V car battery. It is not an AGM battery. Other than its form factor, which is somewhat small, it shouldn't be that hard to find an equivalent battery, just make sure its form factor is close enough. But, electrically, it's very similar to the Gen 4 under-the-hood unit.

Here's a bit more: The 345LN1-MF is a calcium base superior MF battery enabled by the patented double lid structure. It employs a central degassing structure and therefore can be used in vehicles in which battery is installed in the cabin or in the engine compartment. It is not a AGM battery.

 

I believe Toyota of Santa Maria is owned by the same owners as Toyota of San Luis Obispo.
There is another Toy Dealership in Lompoc.

 

In the very rare event things go horribly wrong, you want a battery that can be connected to the exterior venting with ones mounted in the cabin space.

 

This may be true for the Yuasa battery; but if you go with a Walmart of O'riley battery - what are they going to out gas into your passenger compartment? Those cheaper batteries may fit, but aren't going to be the safer Yuasa calcium based battery. Just saying, if the battery fits - don't assume it's up to par and as safe as the OEM. Unless it meets and or exceed all their factory specifications.

 

it is sad that the dealer won't install a non standard battery to do the testing. any 12v will work.

 

Yes, your correct - but if a battery off gases H2 and enhances a spark or fire in the passenger compartment of a car - who whats to take the liability for that one.

 

pg one actually hurt reading it yesterday while also reading about a dealers new car transfer deal offered to another priuschat member, that was not quite as painful as reading this thread and your experiences.

I wonder if the dealer has a recording of that advice ? Priceless !
Toyota Emergency Road Service description was Priceless beyond belief.

I'd call. No need to post if you plan to, have already or not, I can't be sure it would do any good, anyways.