I have a Prius 2008. It has close to 115K miles. The car is showing red triangle on the dashboard and giving P0A80 code. Is it really the battery failure since it has such low miles? I used Dr. Prius free version and Hybrid Assistant apps and have attached their screenshots here. I am new to Prius so not sure if the whole battery needs to replaced or just some cells or is something else causing the battery to look like it has failed. If the battery needs to be replaced what is the best option and what kind of battery or cells or what seller offers the best quality batteries? I am totally lost. Some batteries are for $900 some are $3400. My vehicle is stalled it is overheating too when it runs so I am not driving it anymore. I have attached the screenshots for someone to help me understand if it is really the battery or something else. Note: I am also getting P0420 code but it has been going on and off for a while but I am not sure if it has anything to do with P0A80.
The number of miles driven is less important than time in service. Have you verified that the odometer is reading the true distance this car has travelled? Looking at your screenshots, I wouldn't be surprised if you found that the battery has been monkeyed with by someone prior to you acquiring it. Yes, your battery requires work or replacement. The best option is to replace it with a new OEM from Toyota. (I would do this if the car is in premium condition and you are 100% sure the mileage is genuine.) Everything else is a crap shoot. If you do not have the money, but have time, you could spend many weeks doing a refurbishment. Be prepared for a lot of study and trial and error. Block 3, which contains modules 5 and 6, is definitely very unhappy. One of the modules, if not both, needs to be replaced. There could be other modules you should replace as well. The P0420 could be because the car is not running well due to the bad battery.
How to verify original miles? Is there a tool to check it? Car is not in a premium condition. I just checked on one of the Toyota dealers website and the OEM battery is for $1700 with $1300 core charge. What is the cheapest option for the battery replacement since the car isn't premium condition. Do you think changing the modules or cells would help resolve the issue? Maybe I can change those modules and if the problem is resolved I can sell the car. I heard replacing modules is cheaper. I don't know how to fix cars so I am not sure how to replace modules so I cannot fix it by myself. P0420 code is probably because the CAT on that car isn't original, I found that out after buying the car but I was just wondering if that could contribute to the current problem. Thanks.
that's a great price for a new oem. I think you can find rebuilt for under a thousand, but don't expect it to last too long. you can try replacing bad modules, but it's hit or miss, and that probably won't last either.
I jump on that 1700 price that's what I paid at the beginning of the pandemic but the same deposit they put a 3000 something hold on my card until the old was in their hands. Has to look original no green bean stickers painted cabinets etc
You should figure out your overheating first. Then price the PO420 repair. PO420 is very likely a cheap aftermarket catalytic converter. New Jersey is a carb state meaning a PO420 will fail inspection and may require an expensive oem catalytic converter. If you get those two taken care of for reasonable cost, then the battery. If its a keeper then go oem for $1700 installed by an independent shop for a lower cost than dealer. You may want to bail if the total repair costs quote too high.
Since my car isn't in a premium condition so I was thinking about some cheaper option. I checked some junkyards and they have batteries for $400-$600 but there is no warranty. Do you know a way to test batteries or get them tested before installation? Is there any place you can take them to get them tested before installation?
Overheating happened only after the battery died down. I did some research online and it says that it is possibly bad hybrid battery causing it to overheat. You are right, car's CAT is also not original. I got scammed when I bought this car so it is definitely not a keeper. I am not sure how much I get it for it if I sell it with a bad hybrid battery and aftermarket CAT.
The battery is not going to cause the engine to overheat if that is the concern. That is the number one problem to resolve as it could ruin the engine. The battery temps in your pics are unrealistic especially the -521f. A junkyard battery is no bueno. Plus there is no way short of an advanced disassembly and charge discharge regime to test other than just putting it in and trying it. The odds a 20 year old junkyard battery is good is maybe 5%. A professionally "reconditioned" battery takes bad modules out and replaces them with better used modules. Maybe $1000. Which is likely what you already have since they usually don't last more than a year or two. The cat is also a big hit in a carb state like NJ. If you just bought this car I would take it back. Get a lawyer if necessary as it sounds like deceptive practices.
Yeah there's a whole bunch of nonsense you can do to test batteries are you willing to go by test equipment a dvom so on? By the good battery when your car conks out you keep your battery put it in the next Prius oh you're trying to move to better car! I'm not have 3 to 5 of at any given they all have new Toyoda batteries . So we can worry about other things besides batteries in car for about 8 to 10.. there really aren't a whole lot of better cars so I better round up what I can and keep. I'm not looking forward and trying to obtain a 40 or $50,000 car personally doesn't interest me at all cost maintenance tires . Noop in the generation too I'm as close to driving for free as ever will be even if I go electric and have solar . The Prius is rt up they're with that setup too on all the solar and the electric car will be quite a few years out . The Prius I enjoy the return immediately
If that isn't a problem with the tool used to read the value, then it indicates a problem with the sense wires and/or CPU inside the battery. Corrosion inside those wires and that CPU are fairly common problems, especially in humid locales. That said, if that is the original pack, even if you were to fix those problems (replace wires, CPU, maybe new nuts for the modules) it is unrealistic to expect it to work forever. It is currently 18 years old, which is really pushing the lifetime limit hard. 1700 is a great price on an OEM battery, and if you are at all handy and have some common tools changing the pack oneself is doable. That would also replace all of those parts mentioned above with brand new ones. Having a helper for moving the pack in and out of the car helps though. Also, the old one must be an OEM battery or they won't give you the core deposit back. If you do decide to change it, inspect it when you pick it up at the dealer. The first one I got had apparently been dropped and the plastic "railing" along the side of the modules was broken, so it had to be returned. (This is not a common problem, I have not seen anybody else post in this forum with the same issue. )
I have been getting strange numbers there for battery temps on Dr. Prius app free version. That's why I was suspicious whether it was really the battery or something else causing those odd readings.
Thanks. That's a good point, I will check my battery now to make sure if it is really OEM. I am not good with fixing cars so I'll have to get all the work done through some mechanic. I had heard Prius lasted forever but this was such a disappointment. Almost all Toyotas burn oil and have some issue after 100k miles.
No car lasts more than 250k without major expenses. The gen2 was a more reliable car than a gen3. Not all Toyotas are oil burners but most from 2006-2015 had low tension piston rings which wear out and cause oil consumption. Which includes Camrys, Rav4s, Siennas, Highlanders and more. Typically starting around 100k. Changing pistons and rings fixes it. Your battery will be oem on the outside and most likely will have mix and match used oem modules inside. There are a couple of clearly different aftermarket battery modules people have sold here which are both bad news. One of the realities of life is car salesmen are not our instant best friends and often outright lie about their products. They make nothing unless the car sells. In addition to dealer and used car salesmen we now have car flippers; all who have a big smile but are only interested in moving their car. Usually by clearing all codes and selling as is. This forum also has salesmen selling questionable products using the discount code ploy. The best thing in your case would be a dealer diagnosis of the overheating, catalytic converter and battery. If all are bad and diy is not realistic, find another car.
I have uploaded detailed report just as a last try to see if anyone can find something which shows it is not battery. It is a detailed Hybrid Assistant app report. It is attached as a PDF report. I have added some pics from the Prius screen. I will put it up for sale if it is the battery. Thanks for everyone for replying to this post.
Anybody here knows how much I should I put it up for sale for? It's a 2008 Base model with120k miles approx. It has P0A80 and P0420 code. Rest of the car is in reasonable condition. Doesn't look like it has any accidents. It was part of the fleet of one of depts. of the state. The title does say it was owned by the one of depts. of the state since it was new. It was auctioned off in a state auction and the guy bought it from there and sold it to me. One of the mechanics I know told me to try to change O2 sensors of the car to see if P0420 code might go away but I don't know. Seems like this car is a bad news. Thanks in advance for any replies.
The attachments are not much help on the battery but these 2 pages might show an imbalance. A better view of the data is available from Techstream or your Dr Prius bluetooth app. However your code is definitive enough for a dealer to replace it. Certainly there are temporary diy component level repairs possible or used mix and match battery options. Same applies to the P0420 code relative to the cat. O2 sensors are unlikely as they have there own codes. A clogged cat usually means the engine is an oil burner and normally gets worse, sometimes to the point engine power is compromised. There are illegal hacks to hide the code but do nothing to solve the problem. Its still not clear what you mean about overheating. Is the engine overheating?
Hi folks you have been a great help. I just need to verify something. Upon checking several different batteries online there are some which are cheaper than the other but they say it's a module. So is module cheaper than the battery? This is way it looks like from several listings. This is what the ad says. So does the module need more work than a full battery, is it different from a fully assembled battery? Seems like most of the prices of just the modules are cheaper than the regular battery. I stil don't know the difference. This is the ad from Ebay I pasted below and it says it is OEM. 2004-2009 Toyota Prius Hybrid Battery Pack 28 Cells Modules - Ready to Install Technical Specifications OEM Toyota Modules – Genuine original equipment cells, not aftermarket replicas. Voltage (Per Module): 7.6V nominal Capacity (Per Module): 4.0–4.2Ah (tested and verified) Internal Resistance: <8.0mΩ average per module (ensures low heat generation and consistent performance). Voltage Difference Across Pack: <0.1V spread (ensures even charge/discharge and pack longevity). Load Test: Each module is cycle-tested under load to confirm voltage stability and capacity retention. Sequenced Assembly: Modules are numbered and organized for proper pack configuration. These metrics meet or exceed OEM performance standards — and they’re fully verified before shipment. Every module must pass capacity, voltage, and load testing benchmarks to qualify. Why Choose The Hybrid Geek Transparent Engineering: We publish our voltage, amp-hour, and resistance data so you know exactly what you’re buying. Most sellers won’t. Bench-Tested Assurance: Every module is capacity-tested and voltage-matched in controlled lab conditions. Free Shipping (No Hidden Fees): Unlike other sellers who charge $150+ for freight, our price includes nationwide delivery. 30 Day Warranty You Can Count On: Most hybrid module issues occur within the first week — if a module fails, we’ll replace it promptly for free, and in the rare instance if it fails again, we will replace the entire pack. Specialized Hybrid Experts: We've been in business since 2016. Our team has years of hands-on experience servicing hybrid systems, with members of our team coming from Green Bean Battery, Dorman, LKQ Corporation and Toyota! No Core Return Required: However, if you need us to properly recycle your old battery, reach out to us, and we can provide a prepaid shipping label. Just reuse the packaging your product came in! What’s Included (28) Reconditioned OEM Toyota Prius Hybrid Battery Modules Numbered & sequenced for proper assembly Packaged securely for shipping This Part Fits: Toyota Prius (2004–2009, Gen 2) Toyota Prius (2010–2015, Gen 3) Toyota Prius V (2012-2015, Gen 3) Lexus CT200h (2011–2015) (Also compatible with other Toyota / Lexus hybrids using the same module type. Buyer responsible for confirming fitment before purchase.) Core Return & Warranty Activation Policy Core Return Requirement: None eBay 30-Day Returns: We honor eBay’s standard 30-day return policy. Warranty Policy: We offer a 30 day warranty on this item. If you experience any issues within the warranty period, please contact us directly through eBay. We cannot provide warranty support outside of eBay, so all communication must be done via eBay messaging. Thank you for your understanding! Serial Number Tracking: Each module we ship has serialized identifiers recorded in our database. Important Note: This listing is for individual modules only (28 total) — not a fully assembled hybrid battery pack. Professional installation is recommended. Buyer is responsible for proper handling of high-voltage components. Please note that these hybrid battery modules are previously used OEM modules that have been professionally reconditioned, tested, and balanced to meet strict performance and reliability standards. As part of normal wear and tear from prior use, minor cosmetic imperfections such as scratches, scuffs, or surface marks on vent tubes and nipples are expected and do not affect performance, safety, or function in any way. Toyota has officially discontinued the original vent nipple and tube design found on earlier hybrid battery modules. Beginning with later production generations (Gen 3 and Gen 4), Toyota no longer includes individual vent tubes, as the updated case design integrates internal venting. For this reason, replacement vent tubes are considered obsolete OEM components, and some modules may show normal signs of age or light wear on the vent fittings. Every module in this pack has been thoroughly inspected for structural integrity, pressure venting capability, and electrical performance. Cosmetic wear on the vent tubes is purely visual and does not impact how the module installs or operates in your battery pack. By purchasing this product, you acknowledge and understand that minor cosmetic blemishes and vent-tube wear are normal characteristics of reconditioned OEM modules. These conditions are not considered defects and are not eligible grounds for return under our standard warranty policy.
