The Starter Battery in my 2017 Prius Prime failed about 6 weeks ago (21,000 miles). I'm guessing it probably due to inactivity due to this COVID mess. The battery gave no indication it was on its way out, it went from starting normally, to nothing, overnight. My first thought was I may have left an interior light on, but nope. So I call my local Toyota dealer about a replacement battery only to learn not only don't they have one in stock, but they won't be able to get one for unknown period. Evidently the Prius Prime has a special starter battery? My dealer said they'd put one on order for me and let me know when it comes in. Given that unknown situation I decided to order a replacement battery from Batteries Plus, and it was also out of stock here too. Fast forward 6 weeks later, I haven't heard a peep from my dealer, but Batteries Plus came though with a replacement (model LSI140R). I pick it up tomorrow. Hopefully it's a match. I'm going to keep a trickle charger on this one! I'm curious if anyone has experienced a failing starter battery on their Prime yet?
Numerous threads on this issue already exist. You're not alone. The trickle charger is the correct solution.
The 12v battery does not have to crank the engine. All it does is to boot-up the computer inside of the car so that hybrid battery can take over the rest. I am not sure what is the low voltage threshold but it is likely to be below 12.0v. IMHO, any 12v batteries older than 2-3 years are susceptible to sudden death. You should carry Li jump pack just in case. And, you probably saved a lot by buying a 140R battery from a third party.
NO it is NOT. And yes I am YELLING. A small automatic smart battery tender is the correct solution. That is NOT the same as a trickle charger.
It depends on what it needs to be "rescued" from. If it is flat DEAD or has significant sulfation, a much larger charger is needed.......and sometimes even that won't work. Most cheap trickle chargers have an open circuit voltage of at least 15 volts, sometimes as high as 20. They are current limited because of the tiny transformer. BUT when the battery approaches fully charged, the voltage goes up to something near it's open circuit capacity. It is NOT good to apply that kind of voltage continuously to a battery. A "smart" automatic charger ramps back the charging voltage to a "float" level of about 13.4 volts at reduced current when the battery is full. That type can safely be left connected all the time. Note: Some smart chargers will cut the charging off completely when full and then turn it back on if the battery charge falls off by a preset amount. Those types generally don't do quite as good a job of keeping it at peak performance.
I have used a Deltran "Battery Tender Junior" for a few years. It states it is an Automatic Battery Charger, Model 021-0213, output 12VDC@750MA, Input 120VAC@60HZ 12W with a red light for charging and a green light for storage. I suspect it uses the word Automatic instead of Smart because it was made before we started calling our appliances "Smart". I have used it when gone for 69 and 71 day cruises and it seems to work just fine for me.
Please gently tell us the difference. I may be able to lend some non-Caps information about chargers/maintainer. A simple inexpensive trickle charger (or some battery chargers that have a "trickle" mode) may not have the smart circuitry to monitor the battery condition and could over charge and damage the battery. Products like the Battery Tender Plus series, Battery Saver products, and others have smart circuitry built in to monitor the battery so when the battery reaches its peak charge, the unit only provides a charge to maintain the batteries charge and not over charge it. I've used Battery Tenders for years and found them to work fine, but just recently started experimenting with products from Battery Saver. Some of these Battery Saver products have built in voltmeter monitoring, rather than just a Red and Green LED like the Battery Tender products. In any case, I picked up my replacement battery for my Prius Prime yesterday from Batteries Plus and have a smart charger connected to it. Hopefully with a maintainer connected I'll be able to squeeze more than 3 years out of these battery.
Being the 12v battery is used for minuscule things why hasn’t it been replaced with a newer technology type of battery? Lithium Ion, Nickle Metal Hydride etc. They would reduce the weight significantly. What’s the downside? Seems that worked for the traction battery why not the 12v too?
Nope. O'Reilly Auto Parts, NAPA Auto Parts, and any shop that sells DEKA-East Penn batteries can get them easily. They're the same battery as the one used in the Chev Spark. Group 140R. About $140. https://www.napaonline.com/en/p/NBP75140R?partTypeName=Battery+-+Automotive&impressionRank=1&keywordInput=battery
Hyundai/Kia has done so in the Ioniq and Niro hybrids. A portion of the traction battery is used for the starter, and if it 'dies', you push a button, and the main battery chargers it up. The Ev version of the cars still use a 12v battery for starting though. There are after market Li-ion batteries for replacing the lead acid starter, but cost much more. Then lead acid is well proven technology that works in a wide range of climates. I don't think NiMH ones exist because of the higher self-discharge rate. Li-ion may replace lead acid at some time, but lead acid has that low cost advantage through massive production scale. While Li-ion has demand to meet for traction batteries and electronic goods. Thinking about it, the spread of 48v mild hybrids might do more to end the lead acid 12v in cars. The 12v in a hybrid or EV does more than boot up the computer. It also switches the relays to connect the traction pack to the rest of the car. It is disconnected for safety reasons on shut down. 48v is safer than high voltage hybrid batteries; it can be left connected full time, and thus doesn't need to have a separate starter battery. Because of weight, those 48v packs aren't likely to be lead acid.
Good timing! I purchased the replacement battery for my Prime from Batteries Plus for a bit over $100. Two days later my local dealer called saying they have the Prius Prime battery back in stock. For grins I asked the price, $217.
Doesn't the Prime use an AGM auxiliary battery like the other Prius models? This NAPA battery is a wet cell.
BUT.....when it comes time for a replacement, an AGM still is a better choice......although a bit more expensive.