I'm having issues with a Greentec replacement battery, and was looking for advice, and what others' experiences with this company have been like. Greentec replacement battery for my 2005 Prius installed October 2021. October 2024 the battery began having problems. Car would go from full charge (all green bars) to empty (one or two red bars). Informed Greentec of this problem December 16, 2024. I had 10 months of warranty left at that time. Told to monitor the behavior and they would honor the warranty. Battery continued to demonstrate this behavior. Battery is acting much worse now--the full to empty happens at least once a week. Reached out to Greentec last week, with battery diagnostic screenshots showing inconsistent voltages across the battery blocks: one at 19v, and one at 24v, with the remainder at an expected 21 or 22 volts (if I'm reading the Dr. Prius output correctly). Taylor Barthel at Greentec blows me off with a boilerplate response. I had a bad feeling about the battery when I bought it, as the open part of the case (not the sealed part, the small hatch to connect the wiring) was littered with extra washers and snipped-off connectors, but the battery had excellent performance up until last year, when it began displaying the full-to-empty problem described above. What should I do? The battery is technically out of warranty, but I told them of the problem in December 2024. Is there a better way to figure out what's going on in the battery without opening it? I'm guessing either a bad cell/cells or some loose connections.
3 years is near max lifespan of a rebuilt battery pack before it needs to be rebuilt again. Wish people knew this before they bought it. But the good news is that your symptom is not a bad module, but corrosion inside the battery ECU. So you could open the pack and clean it and you'll able to have a good pack for a little while longer. But still going to have to address battery pack lifespan soon. I'm south of you in Olympia and I'd be happy to help you out, just private message me and we'll make a plan... Or I could elaborate on your options on this thread if you want?
The battery is all new cells, not 'refurbished'. Four year warranty. Appreciate the tip that it's corrosion. I suspected loose wiring/connections, given the behavior. Is the corrosion something I can reach without breaking the warranty seals?
Oh, thanks for clarifying... GreenTec used to only put warranty seals on the cover over the battery modules, not on the cover that gives you access to the connections. If you can unplug the orange safety switch and get that cover off, you'll have access and can remove the ECU and open it and clean it. If I were you I'd file a complaint against GreenTec online with the Better Business Bureau, also get on the phone and escalate to a supervisor or supervisor's supervisor. Be persistent. You brought up an issue with them that is supposed to be covered under the warranty and they don't address it tell them you'll report it to the Attorney general's office.
Thanks so much for this info. I put the battery in myself, so know about that cover and the orange safety cutoff. Is there a guide I can follow for what I should be removing/cleaning?
Not sure how much you paid originally for that Greentec pack 4 years ago. You got more life out of it than the Project Lithium lipo pack that was in my Prius. If you can afford it and plan to keep your car for many more years/miles, a new OEM nimh pack from Toyota is gonna be the most reliable and durable.
There might be something on youtube... But it's super straighforward, just unplug and unbolt the ecu then remove the 4 screws. Also I suspect because you did the install your warranty is for less time than if they did the install... Or at least that's how it usually works.
Thanks. I think I remember the ECU you mean--a metal box to the right of the big orange HV wires. I'll post some pictures when I get that cover off. Can I get to this without extracting the whole battery from the car?
Here we go again. A self-described expert weighing in on something that he doesn't even understand based on the OP's posting. Jesus Christ................with a little bit of reading, comprehension and understanding, here you go: diagnostic screenshots showing inconsistent voltages across the battery blocks: one at 19v, and one at 24v, with the remainder at an expected 21 or 22 volts This is not correct. You are looking at the internal resistance readings of the battery modules not the voltages. Your actual module block voltages range from 16.48 to 16.57 volts, which at first glance the bars look all over the place and makes you think there's a problem, but that's only because of the way they are scaled. They are actually pretty tight, with only a 0.09 difference top to bottom. What you have to understand about your screen capture is that the battery is being charged at 5+ amps and that can hide voltage variation. It would be easier to see deficiencies if the battery were under a discharge condition. As for the green bars to red bars, that can also happen depending on your driving habits. Under what conditions does this happen? How is the car being driven and under what road conditions? Do you see it after the car has sat unused for a few days or is it while actually driving? while sitting in a parking lot with the AC on? Happening once a week is a bit unusual if the pack were actually bad. When you say the pack was made from 'new' modules, were they new prismatic modules from Toyota, new prismatics from aftermarket (ie not Toyota) or new 'D cell' style modules from an aftermarket supplier? This makes a huge difference in expected trouble free lifespan. Just copied this from their website: New, as in BRAND NEW, High-Performance Cells with greater capacity for exceptional performance Precision cell matching using the very latest technology Based on their wording (avoiding saying new OEM modules), and the blurb about precision matching, I'm going to guess they are third party modules. It would be interesting to see a photo of the internals on this battery.
You've been in this forum for less than a year and act like you have knowledge and experience when in truth you're someone who spends more time attacking people trying to help then actually demonstrating your intelligence and knowledge. It's well documented on Priuschat that a sudden drop from full charge in a gen2 down to one bar that quickly goes back up in a mile or two is caused by signal noise due to corrosion in the first pin of the ecu where it connects to the circuit board. Maybe if you spent less time hating everyone and more time learning you wouldn't be such a jerk and people wouldn't hate you so much?
Thanks very much for this ECU corrosion tip. This is exactly the behavior I'm seeing. I wasn't able to keep my original battery case, so it's one Greentec supplied, not the one original to the car.
You have no idea of how wrong you are..............Please show me the "well documented on Priuschat that a sudden drop from full charge in a gen2 down to one bar that quickly goes back up in a mile or two is caused by signal noise due to corrosion". Yeaaah, pretty sure corrosion of significance will also cause it to code.... And please show me in the OP where the member says anything about "down to one bar that quickly goes back up in a mile or two" Maybe we can chalk that up to not reading and comprehending also? Maybe you just see what you want to see? And if you would actually read a post and put 2 and 2 together before going on one of your rants, maybe you could actually provide some accurate advice.
Because you're the super expert that couldn't even recognize that 20+ volts is pretty much impossible, right?
Again, you are providing zero helpful input to OP. Instead you're having yet another troll temper tantrum... And now due to your lack of experience and knowledge of what's on PriusChat you want me to hold your hand and post the links? Why would I want to be helpful towards you when every single day you're endlessly attacking me? What you put out comes back to you...
Never said I was a 'super expert' just me helping people with what I've experienced in my own vehicle and many others. The more I learn and experience the more helpful I can be... It doesn't' work that way for trolls who try to troll harder. Quite the opposite really...
As stated above, you need to define the timing and conditions to see this behavior. Sitting at a stoplight for 3 minutes with the ac on? Or shutdown overnight? Or... As stated above you need to communicate to Greentec with accuracy. They are very likely to brush you off with clearly inaccurate descriptions. The milliohms could be better but not a change out indication yet Dr Prius is not an acknowledged testing standard, it's simply a tool the Lithium/sodium guys put out to display data. The real question is have you gotten any battery codes? Toyota's original ten year warranty for carb states would have required those, much less Greentec. Finally, as stated above, if they sold you the aftermarket cylindrical nimh new cells, we know 2 years is typical and 3 is pretty good. If they are real Toyota oem you are unlikely to have any concerns for another 5-8 years.
