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Optima battery and installation kit for Prius 2001 to 2003

Availability: Usually ships the same business day

Optima-Pr-Cls  US$250.00  

No core charge - turn in your old battery at many auto-parts stores for a store credit.

Has your 12 volt battery failed?

Price includes A write up on how to significantly reduce the engine oil consumption.

  • FAST FREE SHIPPING! Have it the next business day to much of the Southwestern and 2 to 3 days rest all of US (including Hawaii and Alaska) and US territories (including: Guam, Puerto Rico and US Virgin Islands) and APO/FPO military addresses with our free shipping! Click for details! From an APO customer: "I wanted to take time and thank you for your website! I thought I would have to junk the Prius I bought a little over a year ago, but your battery saved her! First off, the item came in much quicker than anticipated, and once the battery was installed and the computer on the Prius was reset, she’s back up and running! I’d much rather pay $200 for a battery than pay another 2,000-3,000 Euros on another used car. Once again, thank you again!

    If you are near Sylmar, CA We will install the battery for free! Call 818 364 9810 for an appointment.

  • Optima D51R battery with 3 year manufacture's replacement warranty! Click here for details. (We expect this battery to outlast your Prius because the Optima Red Top [lots of cranking amps, fewer deep discharges]last 10 years in cars where they have to crank the engine and are exposed to engine heat! The yellow top [deep discharge] should last even longer especially in a Prius! (no engine heat, no engine cranking) We have been selling the Optima batteries for over 3.5 years and they are going strong in the Prius! [We asked!]) Here is the reply from one customer who bought the battery 8 November 2007: "No problems whatsoever. I have one red Optima that is 10 years old and still works fine!" P.G., Cherry Valley, CA
  • Installation kit with 5 pages of instructions and four pictures.
  • Free shipping to all 50 states and US territories via ground to color areas of map below or via Priority Mail all other areas in US not colored on map below.
    You should have your battery in 1 to 3 days!
    Canada customers take advantage of our free shipping we can ship it to a border town an you pay around $5 to have a mail forwarder hold the battery to you. Click here for details. Not in the red and green areas or toward end of week? The map below applies! The dark blue area gets Saturday delivery when you order on Friday. The light blue area gets Saturday delivery when you order on Thursday. Prius 12 volt battery arrives fast!

    "Unbelievably good service!!!! I ordered the battery after 4PM and it was sitting on my back porch by 8:30AM the very next morning----just about 16 hours after ordering. WOW!!!!! Installation with the included instruction was a snap.

    Thanks. Great to know such service still exists in today's world.
    " H. S., Santee, California

    "Just to thank you for extra fast delivery, I got it on Wednesday [He ordered on Monday.] - picked up in local post office and replaced old one." R. M., Franklin Park, Illinois

    Hobbit talks about his Optima battery in his 2004 Prius.

    In stock. Our experience has been so good with the Optima Battery in the Prius 2004 + (less than 1% warranty issues) that we decided to offer it for the 2001 to 2003 Prius.

    Hobbit talks about his Optima battery in his 2004 Prius.

    Note: If you have the Panasonic battery in your Prius the battery hold down tray was also changed. The tray is not wide enough and has to be bent. Because the steel is thick it does require a heavy hammer we used a sledge hammer. Once this is done it works great. Note the differences in the black plastic at the tops of the batteries. If you have the Panasonic you do not need the full kit. Just order the D51R ask for the upgrade instructions in the comments. Click here!

    In stock!

    For Europe, Africa and the Middle East: If you can get an Optima YT R 2,7J you do not need most of our kit. This battery has Japanese electrical posts and should work without the kit if you battery has Japanese electrical post which it probably does except for the Japanese models. Just look at the battery if they are about the same size as a pencil they are Japanese posts.

    "I got the Optima installed this morning. Aside from a little tight fit with the fuse block on the plus terminal and the knife switch on the negative,[We normally do not recommend the knife switch with the optima battery.] all is went very well. Sure was nice to see the voltage going from 12.2 to 12.5 after my 30 minute run.

    Had no error or warning lights - slick.

    Thanks for a great product, and service.

    If somebody 74 can do it, anybody can!

    Regards, and Merry Christmas!


    More Capacity - It is a 38 (10 more) ampere hour battery compared to 28 for the original Prius battery (Toyota Part number 28800-21050 - GS S34B20L). It also has 7 more than the Miata Battery. This is enough capacity to leave the car parked for 48 days! (38 amp hours / .035 amp draw * 24 hour) Two weeks is only an 11.76 amp hours draw or 31% of capacity and the battery is good for over 2000 of these (See graph below.)

    7.5x More Deep discharges compared to other starter batteries. - This battery has thicker lead plates to provide more deep discharges as apposed to lots of cranking amps. (See chart below.) The high voltage battery in the Prius starts the engine not your 12 volt battery so you do not need cranking amps in your 12 volt battery. The Miata battery is designed to start the engine we have no data on the Toyota Prius battery.

    15X Superior vibration resistance! The tightly wrapped spiral design (see cut away image toward bottom of page.) provides superior vibration resistance so you battery is less effected by pot holes, construction projects, drainage ditches speed bumps and rough roads.

    Lower voltage drop and longer life! The lead plates are 99.99% pure lead because the lead does not have to be strengthen with an alloy due to the tight spiral design!

    The three main contributors of premature battery failure are:

    1. Vibration which causes distortions in the plates and eventually shorts.
        This battery is made by sandwiching the acid filled mat and the lead together and then tightly wrapping them in a spiral. This reduces vibration by 15X as a cause of battery failure.

    2. Repeated deep Discharges
        This Yellow Top battery is also chemically configured to handle repeated deep discharges not huge starting currents. Leaving the lights on a few times will not kill this battery! My battery in a 2001 Prius is over 8 years old and still going strong after leaving the lights on countless times! (The car starts but I will notice the light fixture is hot.)

    3. Heat!
        Yes batteries have less output when cold but they also last longer. In a Prius that is partly handled because the battery is in the trunk not the engine compartment!

    Although the height and depth of this battery are the same as the original Toyota battery the Optima is 1.5 inches wider. It fits very nicely but you have to modify the battery bracket. (Very easy to do and takes seconds!) If you are willing to modify the bracket, you will get a battery that last much longer! This battery extends 1.5 inches further toward the back of the car where it is still protected by a plastic vent and still about 4 inches from the back frame of the car. (On a 2004+ with Smart Key the battery is within a inch of the back frame.) However, there is less space for the car to collapse into before the battery is hit and we have not crash tested this installation. (I have to say this for legal reason. The Optima is what I have in my 2001 Prius. Bernie, Onwer eLearnAid)

    Partly installed Optima Battery in 2001 Prius.
    Partly installed Optima Battery in 2001 Prius. Courtesy of The Armchair Survivalist

    Battery ships free to all 50 states and US territories.

    Our free shipping is ground(1 Business day to CA, western NV and western AZ) or Priority Mail (2 to 3 calendar days). If you need the battery as soon as possible let us know in the order comments or call us at 818 364-9810.

    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!

    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 sealed battery is designed to go in a trunk and utilizes absorbed glass mat technology. This advanced battery has little free liquid because it is absorbed into the glass mat. Consequently, there is little acid that can spill into the trunk even if the case breaks. It also has Toyota style vent hole 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.

    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 who installed the Miata battery: "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.)

    If in doubt check the voltage after the car is started. (see procedure below) If it is at 13.8 volts or higher then the high voltage to 12 volt converter is operating and charging the battery and it is probably not the battery that is causing lower MPG. Go to this page for more information on other things to check for.

    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.

    Has your 12 volt battery failed? Prius battery test procedure for 2001 to 2003 Prius Cars

    Prius not starting? Click here!

    The traditional load test for 12 volt batteries tests your battery ability to crank the engine. The 12 volt battery on the Prius never cranks the engine. The high voltage battery does. (So you might be able to get a few more years use out of a battery that fails the load test. However, the less capacity your battery has the shorter the period that you can leave your car parked before you need a jump. It can also affect mileage.) The 12 volt battery only has to maintain the electronics in the car (security system, remote sensors, clock etc.) while the car is parked and then have enough juice to start all the computers and all the 12 volt systems in the car on start up. Once you have started the car a high voltage to 12 volt converter takes over and charges the battery.

    So perform this test after the car has been parked for as long as it would be normally parked to see how the battery holds up under the drain from the security system, clock, memory chips etc. Ideally first fully charge your battery with a charger for sealed lead acid batteries then let the Prius sit parked. (If the Prius is not driven much the charging is very important.)

    • The transmission should be in Park with the ignition off.
    • Engage the parking brake
    • (2001 to 2003)Turn ignition switch to ON. (do not start the engine)
    • Push Display button. (2001 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.

    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. You have to buy a lot of different parts to make this work and to get the truly correct ones are next to impossible. 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. The positive battery connector is also custom made.

    You will need a vise, a large crescent wrench or vise grip,a small crescent wrench or pliers, 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.

    _____ is Optima red top battery _____ is Optima yellow top battery

    soc-% state of charge ocv - open circuit voltage for deep cycle

    soc ocv
    100 13.18
    90 13.01
    80 12.83
    70 12.65 (The 2001 to 2003 Prius has a drain of .035 ampere hours 2 weeks = 11.76 ampere hours [=0.035 amps *24 hours*14 days]or 31%)
    60 12.46
    50 12.28
    40 12.08
    30 11.89
    20 11.68
    10 11.48
    0 11.27 Look at the graph! A battery chemically configured to take deep discharges (yellow top) has 7.5x(300/40) the life compared to the red top!

    From the manufacture:

    optima spiral technology

    The unique design of the SPIRALCELL TECHNOLOGY. provides many features not available in ordinary batteries. The following is a summary

    SPIRALCELL TECHNOLOGY PROVIDES: More plate surface, closer plate spacing, ability to use high purity lead. RESULTING IN: Low internal resistance. This low internal resistance gives you more power in a smaller box, ability to recharge much faster and higher cleaner voltage characteristics during discharge

    Immobilized plates (locked in place). RESULTING IN: Improved vibration resistance, no shedding of active paste material, lower gradual loss of power and capacity as the battery ages. This gives you a battery that lasts longer and performs better throughout its life.

    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.)

    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.)

    Since the 12 volt battery does not start the gasoline engine you can still use the car with a very weak battery. So much so that at least three Classic Prius users have told me that their Prius now gets better mileage with the new battery. I am now starting to get these stories from 2004 + owners also for example:

    "The MPG skyrocketed in my car after the battery replacement. I was getting 37mpg on the freeway and now its over 48mpg. Thank God!"

    So if your 12 volt battery is very weak and your MPG has deteriorated a weak battery could also be affecting your gas mileage. (Both the ignition and the computer engine controls run off the 12 volt system!) On a 2001 to 2003 Prius the engine is initially cranked with the ignition and the engine control computer solely powered by the battery. As a result a very discharged battery can result in P0300 (Random/Multiple Cylinder Misfire Detected) and P3191 (engine did not start), the check engine light and even the red triangle on the central console.

    2001 to 2003 Prius Optima Battery Customer comments:

    " It takes a while in my Prius to get a new tank of fuel consumed, so with just the first tank, my mileage increased from 33.6 to 38.4! That's a 14.45% mileage increase, all because of a new vs. dead auxiliary battery. I also looked back in my mileage records (every re-fuel is logged since I bought it) and the mileage started slipping pretty dramatically 2 years ago.

    The mileage is now back to or above the mileage we were getting at this time of year 2 years ago and earlier. My Prius is running a LOT more in stealth mode. This is something the Prius-driving world needs to know.

    The dealer always said the batteries (including the auxiliary battery) were in 'good condition.' The auxiliary battery I removed had a manufacturing date of February 3, 2001!!! It's December, 2010 when it was replaced - well beyond any expectation. Yet the dealer said 'the auxiliary battery is good.' I questioned the report, but got 'nowhere.'

    Thanks for the great parts and service.

    S. K., Bellevue, WA

    "Got my battery and installation kit yesterday. Put it in today. Worked perfectly. I probably spent about an hour doing it. A lot of that was the double setup and cleanup because I went to the grocery store for my test ride. The installation instructions helped a lot. I consider myself a fair hand with a tool but it would never have occurred to me to put a mat down for my knees. Thanks.

    All in all, extremely happy with the battery and installation kit. Customer service is great too.
    " C. H., Stafford, VA

    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.

    Availability: Usually ships the same business day

    Optima battery and installation kit for Prius 2001 to 2003 Optima-Pr-Cls  US$250.00  

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