Got in my 2022 450h last evening and it was completely dead. Nothing worked. All I got was the yellow triangle with an exclamation point in the driver display. No messages. I could not open the rear hatch to access the 12 volt battery so I opened the hood and connected a CTEK charger to the posts in the fuse box. After several hours, the alarm light on the dash was flashing red but the charger was showing little progress. I left the charger on for about 10 hours and it still did not show a charged battery. I took a chance and disconnected and tried to start the vehicle. It started right up, so I moved it outside and let it run for 20 minutes. After moving back inside I then connected the charger directly to the battery. After several more hours it finally indicated level 4 on the CTEK (useable but not complete). I'll leave it on the charger until it gets to maintain/trickle charge.

With the lights off in the garage, and in total darkness, I verified that no lights were on and that no doors were open. I have no idea what could have run this battery down to the point where it would not permit the vehicle to start from the hybrid batteries.

This is a little concerning for a vehicle with just over 5000 miles on it. We purchased it in November 2021. I will be in touch with the dealer first thing tomorrow (Monday) morning. This is our 4th 450h and the first with a problem that I can recall. So, overall I am still happy.

 

What battery did it come with? Is it still the high quality Panasonic OEM or random brands now?

 

I took the cover off of the battery and could not tell. There were no markings of any kind visible. I would have to remove the battery to see all of it.

It finally went to float charge after about 17 hours on a charger! For a 64 aH battery, that is way too long to charge!!!

 

If it’s not the OEM Panasonic AGM battery that they used to provide in the Rx hybrid, and just a normal flood lead acid. Any complete discharge would have shortened the life span of it already.

 

The manual says that it is an AGM battery. Does any modern vehicle manufactures use flood lead acid batteries anymore?

 

Yes. Plenty do, if they can get away with it. Even Toyota uses flooded batteries with their hybrids these days. Cost cutting.

 

One way or another get another battery, if it is not the charging system

 

**UPDATE**

The dealer had the vehicle for two days and ran "every test imaginable" on the battery and the charging system. They looked for phantom loads overnight and then ran many of the tests a 2nd time. Everything came back looking good. I guess that is good news, but something caused this to happen, so we will surely be nervous going forward. One good positive, the dealer did not charge us for any of the work, and we had a new RX350 loaner for two days.

 

I have had AGM batteries for years in golf carts, and when the cart starts acting up it is always a battery issue. Batteries Plus always says that they find nothing wrong with the battery, however, when I put a new battery in all the issues go away. Something about AGMs that must give back incorrect information. If the charging system is good, then get a new battery---they are cheap enough to replace and not have to worry any more..

 

@wa3cuj I had a similar issue with my 2010 HS250 AGM battery. The dealer found nothing wrong. A couple of weeks later, dead again. They came to my office and changed the battery at no charge. Never had an issue after that. If it happens again, have them replace the battery if still under warranty.