12 Volt (12v) Toyota Prius Auxiliary Battery for 2000, 2001, 2002, 2003 with installation kit and free shipping to 48 states

Click here to for a 12 volt battery for a 2004, 2005, 2006, 2007 and 2008 Prius.

If you want to purchase the battery separately Click here.
Join hundreds of other Prius owners how have installed this battery with our kit! It is easy! (This is a battery and installation kit for a Prius 2000 to 2003.)

Prius owners: Why pay an outrageous price at dealer for a 12 volt battery? I did not and you do not have to also! Just say no and replace it yourself! This battery is almost the same size but a little shorter, has American electrical posts instead of Japanese, and has two vent tubes instead of one. Our kit with instructions handles these differences so it is an easy replacement and everything fits! When you are done you have a battery with 10% more capacity than the original!

Our free shipping is UPS ground or Priority Mail (2 to 4 days) whichever will be faster! Toward the end of the week most of the orders go via Priority Mail because UPS does not move packages on weekends.

In a hurry? You can call us at 818 364 9810 up to 6:30pm. If we are in and can get your products out for you we will!

Now available in Canada go to bottom of the page.

• Voltage 12 (12v or 12 volts)
• Amp Hour 31
• CCA* 320 (Cold Cranking Amps)
• Shipped fully charged ready to install
• Maintenance-Free
• Valve-regulated absorbed glass mat (AGM) eliminates acid spills and terminal corrosion.
• Vent hose attachments for emergencies in case the battery is heavily overcharged.
• Resists vibration and heat for longer service life
• Length 7 1/2"
• Width 5"
• Height 7"
• Weight 25lbs
• Warranty: 4 year: first year exchange, balance pro-rated - excludes damage due to misuse or neglect, improper charging or improper application of battery

  We ordered one other Prius battery and had it replaced under warranty. Wanted to let you know we found the cause of the drain - we had an aftermarket car stereo causing steady drain even with the ignition off. That's finally fixed, and we're replacing the weak battery for what we expect will be the final time, and we don't expect warranty coverage. Thanks for your excellent support in the past! R.T., Fort Collins CO
  
  

• Made in USA
• Free shipping to 48 contiguous states. Battery ships from Los Angeles via UPS ground or Priority Mail whichever is faster so you should get your battery in one to three days!
  
  The Federal Magnuson-Moss Warranty Act of 1975 prohibits a manufacture from curtailing warranty coverage due to after market parts unless it can be demonstrated that they caused the problem. (For more information click here and scroll down go to paragraphs under "Tie-In Sales" Provisions.)
  
  

  This battery is designed for the Mazda Miata and fits any Miata from 1990 and later. This battery is has more electric storage capacity (takes longer to discharge) than the original Miata or Prius Battery. This is because the battery is made with machines that insure the chemicals are evenly mixed and that the battery is completely packed so there are less air pockets that robe the battery of it's performance.
  
  This Mazda Miata battery also fits in the original Prius battery holder of the Prius 2000 - 2003, when installed with our kit with instructions. This battery also exceeds the storage capacity of the original Prius Battery (Toyota Part number 28800-21050 - GS S34B20L) which has 28 Amp Hour rating compared to 31 Amp Hour for this battery. (A 10% improvement.) Since the battery is a sealed battery, it has the same electrical characteristics as the original Prius battery but it has more capacity. It has been put into over 200 of classic Prius (2000 to 2003) cars with no problems. When I took mine to the dealer for service their only comment was favorable regarding the bigger grounding cable we supply with our kit.
  
  This sealed battery is designed to go in a trunk and utilizes absorbed glass mat technology. This advanced battery has no free liquid because it is absorbed into the glass mat. Consequently, there is no acid that can spill into the trunk. It also has attachments for a vent hose so any gases are vented outside of the car. The battery does not normally emit gases but can do so with heavy over charging with pressure building up and the valves in the batteries releasing. This should not normally never occur because the Prius high voltage to low voltage converter puts out around 13.75 volts. 13.75 volts is the voltage the battery puts out at no load and at that voltage the battery can not be overcharged and it is the maintenance voltage for the battery. However if one cell shorts out or the voltage unexpected goes high gassing can occur. If gassing does occur the gas passes through the vent tube. Our Prius kit extends the original vent tube because the connector is on a different side of the battery.
  
  The 12 volt battery is not used to crank the gasoline engine in the Prius but it does supply all the 12 volts circuitry which includes all of the computers in your car. If this battery fails, the computers will not start and the Prius will not start. A weak battery can also pull the 12 volts power down to a lower voltage. This can cause problems with all of the computers that control your car. (When I had a problem with my car the first thing the dealer insisted I do was replace the battery. The problem was caused by something else but the battery was weak.)
  
  

  Because this battery does not start the engine in the Prius it can be used after it's output has seriously declined and at least three users have told me that their Prius now gets better mileage with the new battery. One told me that getting a new battery restored his mileage back to the original mileage he was getting when the car was brand new and another told me that he is now getting better mileage then he did originally. Here is the third owner's comments: "All installed and working GREAT! My mileage has jumped amazingly (>10 mpg). Would have saved considerable amount of money by replacing earlier. Thanks again for being there." (for another similar story go to the bottom of this page.)
  
  So if you 12 volt battery is weak it could also be affecting your gas mileage because your Prius is wasting energy trying to recharge a battery that will not take a charge.
  
  

  Another user had let the 12 volt battery degrade to a point that he had to turn the ignition on and off four or more times to start the car. He told me his gas engine would never shut down when he was driving.
  
  In short, if your 12 volt battery is four or five years old we recommend you replace the battery. The normal battery life is four to five years.
  
  

  Prius battery test procedure for all Prius Cars 2000 to 20008

  Here is a battery test you can perform on a Prius battery that is easy to do.
  
  However, this test requires no tools, is easy to do and will give you some idea of the state of your battery. You can also perform this test after the car has been parked for a while to see how well the battery holds up under the drain from the security system, clock, memory chips etc.
  
  

  • Do this test after you have driven the car for at least 30 minutes. This will give the battery a chance to be fully charged.
  • Put the transmission in Park.
  • Turn ignition switch to off.
  • Engage the parking break
  • (2000 to 2003)Turn ignition switch to Accesory. (do not start the engine)
  • Push Display button. (2000 to 2003)Top rocker to the right of the radio 2004+ top button to left of screen - "DISPLAY" will now appear in the upper left corner of your screen.)
    
    
  • Push on the upper left(1) of the display just inside the box, withdraw, push on the lower left of the display(2) and withdraw. (see picture) Do this three times. Keep trying till the screen changes. If the word "Display" in the upper left hand corner of the screen goes away hit the display switch again.
    
  • Push on Menu in upper right of display screen.
  • Push on Display Check
  • Push on Vehicle Signal Check
  • You will see the 12 volt voltage displayed.
  • With no electrical accessories on including lights the voltage should be fluctuate between 12.2 and 11.9. The lower the voltage, the less of a charge your battery currently has. If the voltage is low do not proceed as the load test might totally discharge your battery. (If you see a voltage around 13.5-13.8 you are seeing voltage from the high voltage battery being converted to around 13.5-13.8 in an attempt to recharge your battery. This normally does not occur till after you start the engine but might occur earlier if the battery is very drained.)
  • You can also test the battery by turning on the headlights, rear window heater and the heater fan. For a new battery the voltage would be around 11.3. If the voltage drops below 10.2 it should definitely be replaced. For voltages in between the lower the voltage, the lower current charge of your battery.
  • Note: If in doubt disconnect the 12 volt battery completely (start with the negative post to avoid shorting the battery) and hook it up to a battery tester.
  
  
  The original Prius Battery GS S34B20L (Toyota part number 28800-21050) has Japanese electrical posts, which are smaller than the American posts, which come with this battery. This new battery is also shorter and has two vent hoses instead of one. For the Prius you can not buy off the shelf parts to make this battery work. So we recommend you save the time and trouble and also get our installation kit which includes all the parts you need and installation instructions. Our kit has has everything preassembled as much as possible to save you time.
  
  We bought a number of things that did not work quite right in developing this kit. Save yourself the trouble and purchase our kit. You will not save much buying and making the parts yourself. We make the battery riser because we could not find one on the market after a lot of research and the positive battery connector is also custom made.
  
  You will need a vise, a large crescent wrench or vise grip, a 10MM wrench, some tape, two flat edge screw drivers and a 1/2 inch wrench. You have to follow the normal precautions of disconnecting the negative battery connector first and connecting it last or your can short the positive connector to any exposed metal in the car. If you follow the instructions, that come with the installation kit, you will not short out the battery but you may want to buy the kit and have your battery professionally installed.
  
  You will save money and get a stronger battery!
  
  Note: If you dealer replaced the original GS Battery with a Panasonic 12 volt Battery he also replaced the battery hold down brackets and this battery may not fit securely in the new tray. Compare the top of your battery with the picture below to be sure. (The battery is located behind a cloth coated plastic panel in the left side of the trunk. There are three plastic snap down holders. Depending on the connector you push in the center button to let it snap out or if no center button you pry them loose with two flat edge screw drivers on each side.)
  
  Original Nippon Denchi GS S34B20L battery - Toyota part # 28800-21050
  
  Customer comments:
  
  "Thank you very much for the Prius battery and conversion kit. I had no problem installing it, and the car is now running great. I really didn't expect to get better mileage, but it appears that your claim is true. Prior to changing the battery, I was getting 45.5 mpg. Since changing it, I have put 500 miles on the car, and so far, I am getting 48. Very impressive!!
  
  I was very pleased with the fast shipping, as I ordered the package late Tuesday and received the battery on Friday and the conversion kit on Saturday. Thanks very much for providing this service, as it is a real cost saver!!"
  
  H. F., Basye, Virginia
  
  "Thank you! I received and installed the Miata battery in my 2001 Prius in the first week of December, using your kit. For the past three winters I've faced a constant struggle to start my Prius in temperatures below 20F, which are quite common in Chicago. My Toyota dealer recharged the original battery, replaced it and recharged the replacement twice over those three winters. Those solutions never lasted more than a few weeks, and after one recharge my problem was back within a couple of days. I was resorting to one of those Black & Decker portable, cigarette lighter based jump starters and I typically had to recharge it every other day and wait 3-5 minutes for it to work in the car, each and every time.
  
  Anyway, to make a long story short, after nearly two months with the Miata battery my car starts as quickly at 0F as it does at 60F. If not for this product I would have traded my Prius in by now (I came extremely close to doing so just a day before I found your website). The very reasonable cost of your battery and kit will probably save me thousands of dollars over time, as I'm hopeful now that I can keep my Prius (which is in excellent condition otherwise) for years to come."
  
  Cheers, J. M. Evanston, IL
  
  "Well I received the battery today and it took me about 30 minutes to install it. The wood block [battery riser] worked fine. I would like to suggest that if possible, make a kit with a switch to disconnect the battery when the Prius is not going to be used for three or four weeks (like when I am on vacation). If you make a kit for the on - off switch, let me know."
  
  "Thanks for the battery and the part kit. Most of all, thanks for coming up with the idea to market it, it saved me a lot of time and effort.
  
  Best regards,
  
  Dan"
  
  We have added a disconnect switch! See below.
  
  "I had been seeing a slow, consistent drop in my mileage (mid 30s during cold weather) over the past few months. I was suspect that the 12v battery was going bad (I have a 2002 Prius) and found your site on the net. I ordered one of your replacement batteries and install kit, which arrived in just a few days. Installation was straight forward, except getting the nut loose from the positive side terminal, that thing is on there! I saw an immediate jump in my mileage, back to the low 40s. It amazes me that the 12v battery was taking so much energy from the system. Anyway, I just wanted to thank you for the great service and a great product." J. B., Eugene, OR
  
  Please Note: California Proposition 65 Warning Battery posts, terminal, and related accessories contain lead and lead compounds, chemicals known to the State of California to cause cancer and reproductive harm. Wash hands after handling.
  
  
  

  12 Volt (12v) Toyota Prius Auxiliary Battery for 2000, 2001, 2002, 2003 with installation kit and free shipping to 48 states miata+kit  US$133.95