Hybrid battery topping out after repair?

[snakeman]

OK, not the best subject line....

Long time lurker back to post with a question. My 2007 Prius was hit from behind by a Ford Explorer about two months ago. The damage was mostly cosmetic and I was able to drive it just fine for the three weeks it took to get everything worked out with the insurance company.

After that, I took it to the repair shop who had done work for me before on a previous Prius. They had the car for just over 6 weeks. You can see pictures here until they take them down by clicking on number 291:

Check Vehicle

As you can see, the work was mostly body work on the rear bumper, rear hatch, rear body panel, and associated structural things. They said they didn't have to touch the electronics in any significant way other than lights and such.

Anyway, they took it to the dealership yesterday because it was giving some error codes that they had to have cleared. The dealership is where I get service and I trust their techs.

Now, my blue baby is back in my possession but it is doing something strange. It seems like the battery doesn't hold a charger. The display on the touch screen goes from full green bars to two purple bars in the ~30 seconds it takes me to back out of the driveway and recharges from that state to full green again in the length of stopping at an intersection. While stopped for a light cycle, with nothing running other than the radio, I can visibly see 3-4 bars drop off the display in ~45 seconds. It then charges up again just fine with driving.

In short, it seems to cycle between empty and full very quickly. As an experiment, I sat it in the driveway with nothing no but the radio (it was in ignition on mode so I could have driven it) and watched as the battery display drained two two bars, the engine kicked in for less than 30 seconds, it charged up to full on the display, the engine shut off, and the cycle repeated about three or four times.

I've already requested information about the error codes from yesterday and waiting to hear back. I'll be calling the body shop and the associated dealership tomorrow to ask them to resolve the problem. However, I wanted to see if any of the technical experts here have any thoughts on possibilities that I should explore or things I should ask the techs when I bring it in.

Thanks in advance guys.

[TonyPSchaefer]

Wow. I've never heard of a Prius battery discharging and recharging that quickly. I wish mine would recharge that quickly but the discharge is a bit disturbing.

I don't know much about the battery so I'm going to let one of the many experts answer this one though I'm anxious to hear what's causing it.

[snakeman]

I should also note that the battery does hold a charge. I parked it showing full green bars on the touch screen display, was inside for about an hour and a half, and it was still all green when I came back out and turned the car on. Unfortunately it discharged completely over the length of my driveway.

Because of this, I don't think anything's shorting or draining the battery. However, I'm concerned that there's a sensor of some type that's messed up or else the battery has been topped out through some sort of improper charging so that it won't charge properly.

[Patrick Wong]

It appears that the traction battery was left in the vehicle while the body repairs were being performed. I am wondering whether the battery may have been damaged by the high temperature produced as heat lamps dry the freshly applied paint.

[richard schumacher]

Is that body shop in some way associated with a Toyota dealer?

[bwilson4web]

I would ask the dealer to survey the battery module voltages. It sounds as if one or more has gone weak. The heat lamp is a credible hypothesis. But you are under the warranty period so get it checked and documented.

GOOD LUCK!
Bob Wilson

[snakeman]

Originally Posted by richard schumacher

Is that body shop in some way associated with a Toyota dealer?

Actually, yes. The body shop is Woburn Foreign Auto Body and they're associated with Woburn Foreign Motors. The body shop had done great work repairing a previous injury to my Prius from Boston traffic and the dealership is where I've gotten my Prius serviced (the current one and the previous one) since I've been driving them so I feel confident that they can track down and fix the problem with little shenanigans.

However, I ask here in order to go in prepared just in case. Also, it may help others later.


The heat hypothesis has some merit in my mind. Especially since part of the repair was to replace the rear body panel which involved welding a new piece of metal to the frame in the rear of the car and I can clearly see the battery pack in the photos.

Keep the ideas coming and I'll be sure to update here with any developments.

[qbee42]

Did they do any welding? Did they disconnect the HV battery pack?

Since the repairs were in the back of the vehicle, the first place I would look would be around the HV battery pack. You have to wonder if any of the connectors are loose or damaged, or damaged wires.

Tom

[richard schumacher]

[damn the lack of a delete function in this package!]

[snakeman]

Originally Posted by richard schumacher

"Foreign Motors" doesn't sound like a Toyota dealer. If they don't have a certified Prius technician or the Toyota manuals then there are several things they might have done which could damage the battery.

Actually, they are a Toyota dealer and have several Prius technicians on staff. The dealership sells only Toyota, Scion, and Jaguar and those are the cars the body shop specializes in.

Originally Posted by qbee42

Did they do any welding? Did they disconnect the HV battery pack?

Since the repairs were in the back of the vehicle, the first place I would look would be around the HV battery pack. You have to wonder if any of the connectors are loose or damaged, or damaged wires.
Tom

I'm most concerned about the possibility of a loose connection somewhere or a dead cell in the pack. After a quick call this morning, the theory I'm getting from the body shop guy (who claims to have talked with a tech after talking to me) is that the battery did a deep discharge due to sitting in the shop disconnected for 6 weeks. He thinks normal driving will 'charge it up again' and everything will be fine. I think he's thinking it's a lead-acid battery like a standard car and will be getting a second opinion. Planning to bring it to Acton Toyota to see if I can have one of their techs take a look and give me an opinion.


One other thing that he mentioned is that there was a part that they replaced associated with the electrical system. I'll get the name from the paperwork when I'm home tonight, but he described it as sitting near and to the left of the small aux. battery in the back. Any thoughts that this brings up?