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Optima battery terminal question

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by icewind.rogue, Jul 26, 2021.

  1. icewind.rogue

    icewind.rogue New Member

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    I'm new here and I've been looking around at different threads that have been quite helpful with my prius. TLDR: skip to the italics.

    So on Friday, I drove my prius 2 miles up the road to get a drink from the gas station. When I got back in, the car would not start. It was totally dead. I thought it might have been the key fob. I got a ride home, and hopped in the other car with the spare fob. Oddly, the car started making some noise, but wouldn't start. I thought I had either a dead fob or hit the key button by accident. Then all of a sudden the car started. But, being that I drove the other car, I couldn't drive it home ha.

    Ok, so today I went down to O'Reilly's to pick up the Optima Yellow Top. The battery that was in there....whoever installed that should be hung out to dry...they installed some Napa battery IN A GROCERY BAG!!! It wasn't even vented properly and how this car didn't explode, I will never know. There was battery acid everywhere in the bottom, the posts were caked and the vent plug was just hanging around. I have only had this car since the end of May.

    Of course, O'Reilly's couldn't install the battery there because they're not allowed to install "difficult" batteries. So, when I got home I discovered the terminals are too big for the Optima posts.

    So, that brings me to my question.......the kit that is mentioned from elearnaid, is that to convert the original prius terminals to fit the Optima pencil posts? Can I get the post kit from somewhere else so that I can install the new battery ASAP?? Sorry that I do not know if these terminals are OEM or not (I haven't researched it yet as I figured asking would be faster than sifting through links for the right answer).

    And, yes the OBD2 reader showed the code for "Lost Communication with Battery Energy Control Module A." I had the red triangle with the engine light. But, after I got the car back home on Saturday and started the car again, it went away.

    While at O'Reilly's the car wouldn't start again. After a few minutes it's starts. I'm assuming it was because we messed with the battery to test it. Since we took the battery out we cleaned all the corrosion off the posts and re-inserted it until I can get the right terminals. It started at least.
     
    #1 icewind.rogue, Jul 26, 2021
  2. archae86

    archae86 Member

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    Optima Yellow-top sized to fit 2nd-gen Prius actually comes in two distinct models, these days. One has fat posts of the size common in automobiles sold in the USA for years, while the other has narrower posts that fit the clamps with which Prius 2nd gen cars arrived from the factory.

    Years ago, Optima only had the fat-post size, and elearnaid sold lots of kits of a fat-post battery plus a conversion set of hardware and instructions. A problem with this conversion is that once you have done it you are committed to fat-post batteries unless you undo the conversion.

    My personal experience with Optima has been good. On my wife's 2006 Prius, I bought the elearnaid kit and converted to fat-post with a fresh Yellow-top in 2011, having gotten what I thought were clear signs of initial aging distress from our OEM 12V battery. When I decided to replace the 12V battery in 2019, I opted for the Optima fat-post model in order to avoid trying to find my previous hardware and undoing the conversion.

    Years ago the Optima Yellow-tops were highly regarded by some prominent posters here. More recently some have cited evidence they regard as indicating a decline in quality.

    TLDR: elearnaid does offer a $20 kit to convert a Prius with battery clamps for narrow (as provided OEM) posts to USA standard fat posts. BUT, it seems likely your vehicle was already converted, as apparently it now wants fat posts.
     
    #2 archae86, Jul 26, 2021
    Last edited: Jul 26, 2021
    bisco likes this.
  3. icewind.rogue

    icewind.rogue New Member

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    Yes, the battery that is currently in the car is fat posts. So, I will either need to get the fat post battery exchanged out or find shims. But, honestly, if you saw the positive terminal, you would probably cringe. It looks like crap, rusty and misshapen. I would probably be better off getting new terminals altogether. It's just a matter of making sure I get the right size for this project as I don't know what the originals were. Thanks for the reply!

     
    #3 icewind.rogue, Jul 26, 2021
  4. PriusCamper

    PriusCamper Senior Member

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    You think your last battery was bad... Optima will be even worse. They're a bunch of criminal operators who sell junk batteries and charge up and resell them when they get returned as defective. Take that battery back and get a real one with way more amp-hours for a way lower price here: https://ebay.us/vN4JsP

    YellowTop_Criminals.png
     
    #4 PriusCamper, Jul 26, 2021
  5. RobertK

    RobertK Member

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    Was the NAPA battery the same size as your Optima? If so, it looks like your car got converted from JIS (thinner) to SAE (fatter) posts. You need to get a group 51 battery if you want to use the SAE terminals that appear to be in your car.

    The battery should be AGM and should have a connection for the battery vent tube. You probably bought the Optima S46B24R battery. Take it back and get the Optima group 51 battery and it should fit. If your car has keyless entry, one of these two batteries is a drop-in installation depending on the terminals. If you don't have keyless entry the car came with a slightly smaller battery and the battery hold down will need to be modified or replaced with the hold down for the larger battery. This has probably been done when your NAPA battery was installed.

    I had the Optima S46B24R in my Prius for nine years, driving about 5000 miles per year without any issues. The battery might have lasted longer if we drove the car more. I bought the NAPA S46B24R because it was less money ($166 vs $235) and was in stock locally.
     
    #5 RobertK, Jul 26, 2021
  6. icewind.rogue

    icewind.rogue New Member

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    No, the Napa battery was SAE.

    I ended up using shims on new terminals, since the terminals that were on it (the SAE converted ones) were in really bad shape and went ahead and replaced the lug on the negative cable since it was literally hanging by a thread....or a few anyway.

    I haven't had any issues with the car starting today either.

    @PriusCamper I guess the Optima's are hit or miss around here, as most of the comments I've read suggested it, which is why I went with it. Just wish I had paid more attention to the terminals before I went down this road, ha.
     
    #6 icewind.rogue, Jul 27, 2021
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