Looking for others with 12V battery problems for class action lawsuit

This has been posted here many times.

The problem occurs when the car sits at the dealer lot for too long before it is sold, or when it is not driven frequently. Once the 12-V battery SOC drops too low, the 12-V BMS (battery management system) will no longer fully charge the battery.

The solution is simple. Get a Noco Genius battery maintainer and hook it up when you first buy the car, then again every few months. This will ensure the battery stays fully charged.

 

I was fooling around with the car yesterday. Removing the negative lead off the battery only causes loss of tank mpg, far as I can tell, on my LE. No big deal to open the rear door with the interior handle, fold down seat and reach in and put lead back on. I guess you could do this on a locked car, opening the door with the mechanical key.

 

I am curious to how well a Gen 5 Prius would do with an AGM battery vs. the stock flooded 12v battery. Maybe it solves the problem? Otherwise it could be a Toyota software problem in the car. They can fix how the car interacts with the 12v battery while not being driven regularly.

 

I believe that the 12V battery is classified as a wear-out item; like the tires and brakes - but I wish you Luck in this endeavor..........

The easiest way to manage this issue is to connect the car to a RV battery tender, whenever your gone for more than a week. That should resolve your issue. There's also a TSB for the PHEV version that places their systems in "sleep mode" faster to prevent 12V battery discharge.

Hope this helps.....

 

let me know if you go ahead with the class action, are you an attorney?

 

This is not a Prius problem. All new cars have the same problem. If there is going to be a class action, it should be against the entire auto industry.

That said, I addressed the cause and solution of the problem in Post #2.

You don’t need an AGM battery, but if you need a replacement battery, AGM is definitely better because it is a better battery. It won’t solve the problem if the car is being driven infrequently, though.

AGM battery for Gen 4/Gen 5 Prius/Prius Prime and observations on the 12-V charging system | PriusChat

 

Now, don’t do that. LOL.

 

This all sounds like lots of bother!

Just unplug the sensor on the negative terminal. This disables the stingy 12 volt charging logic and charges at a constant 14.3 volts, whenever the car is in “Ready” mode, similar to old school alternators. No warning lights, no issues will arise.

I agree with disconnecting the 12 volt negative terminal but only if you’re storing the car for more than a week or two.

 

Class action? Lol... There's a well established history of hybrid and EV cars not providing enough amps to keep the 12v charged and because Toyota sucks at software the problem is likely way worse with Gen5 Prius and their clumsy app as relates to vehicle software.

This isn't product liability, this is a normal reality you need to know about and prepare for as a hybrid vehicle owner. Regular fuel based vehicles have big alternators producing huge amounts of amps, that's not how hybrids and EVs are designed because they produce way more amps that are used for more meaningful things than a lowely 12v.

The solution is that you wire in a switch to the negative wire to ground next to your 12v battery so you can turn off the power when you aren't driving for a while.

If you'd like to learn more about this problem that's pervasive across all EVs and Hybrids, even Tesla you can learn more here:

How Hybrid Cars Power the 12V Battery Without an Alternator?

https://www.fleetnews.co.uk/news/warning-over-12-volt-battery-on-electric-vans-suddenly-draining

 

That will reduce the battery life, though, because you are constantly charging the battery, which will be overcharged frequently. That’s why the old-school cars needed a battery replacement every three years or so. The Gen 4/Gen 5 Prius battery will last for ten years if the car is driven frequently or if a Noco Genius is used occasionally.

 

They have been having this exact same debate with Honda Insight Hybrids for 25 years... And its hilarious to say constantly charging the 12v with a low amp weak sauce charge when vehicles for over a hundred years have been pumping a huge amounts of amps into healthy 12v every time the car is running with no issue of shortening the lifespan of the 12v.

The problem here is 12volts are not getting charged enough and pulling that sensor will increase charge to the 12v and that will NOT damage the 12v. And granted if the 12v is fully charged all the time that can shorten lifespan, but the problem with DC to DC converters charging 12v is they will never give the 12v enough amps to keep it fully charged unless you drive 12 hours a day everyday because from the car designers perspective, they don't take a drained battery problem as design flaw even though the cars inability to easily recover from a drained 12v is a design flaw.

Probably the best solution is to buy a 12v with bluetooth controller so you can use an app to assure you're both monitoring and optimizing how much charge your 12v gets. This 12v for instance even has a power button so you can ensure no parasitic drain when not driving your car for a while: The ultimate 12v auxiliary battery with JK Active-Balance Bluetooth - NexPower Energy

 

If you don’t drive much, it won’t overcharge the battery, but if you drive regularly, applying 14.3 V to the battery for hours a day, every day, will definitely overcharge it, cause gassing, and significantly reduce the battery life. It can kill your battery on a many-hour-long trip.

 

It charged at 14.3 V all the time during the winter. As soon as it got warmer, it went to 12.7.

 

This is not much different then you showing up to a conversation about people not having not enough food to feed their families and you won't shut up about how bad it is to have too much food to eat. Maybe you need to do a personal context check and correlate it with the actual reality of the conversation you're participating in? PS: it's not the voltage of the charge its the amps... And weak sauce amps doesn't damage this type of 12v even if you left your car in ready mode for weeks and weeks.

 

The main DC–DC converter is not a weak current source. It provides over 5 amperes at voltages above 14 V, perhaps even over 10 amperes.

By the way, I’m an electrical engineer.

 

Was the 12V battery already 'wounded' when you received it, from sitting around and draining on the dealer lot? This is not uncommon.

That sounds like ordinary boilerplate for many modern vehicles, including non-hybrids, that are never truly "Off". The "2 weeks" is really just CYA if the battery is reasonably healthy, it doesn't really need charging that often until the battery is unhealthy, which can happen even on newly purchased vehicles. Especially if it sat on a dealer lot for a long time before purchase, or if some else mistakenly left something on that drained the battery.

At this point, you have no basis for an individual lawsuit, let alone a class action suit. Just a single battery failure that was covered under warranty, plus some CYA words from the dealership. If the new battery is healthy, it is unlikely you will have this problem again over just 2 weeks trips, absent any electrical problems that should also be handled under warranty.

I started topping up batteries before and after long trips (much more than 2 weeks) with my 2010 Prius, and found a similar issue in the household's modern non-hybrid too.

 

It was only max 3 to 3.5 amps for a gen2 Prius and all the poorly designed garbage they added to Gen5 required them to boost it to 5amps and people are still ending up with dead batteries while you're warning them about dangers of over charging?

Meanwhile a non-hybrid (2007 Corrolla for example) has an alternator that can provide up to 100amps to the 12v.

Strange you aren't warning people with cars that can charge 12v up to 100amps, but instead lecture people with dead 12v in their Gen5 about the risks of too much charge. This is absurd and not helping OP at all.

 

There is no overcharging if you don’t tamper with the BMS sensor. There could be overcharging if you disconnect the BMS sensor, which you probably shouldn’t do.

Up to 99% of Gen 4 and Gen 5 owners don’t experience problems. It is only a problem (1) if the car sits for too long at the dealer’s lot before it is sold, and (2) if the car is driven infrequently. I explained the simple remedy in Post #2. I keep repeating myself because people who don’t even own a Gen 4 or Gen 5 keep wildly speculating.