RX400H - Pitfalls of buying a used battery?

Discussion in 'Lexus Hybrids and EVs' started by DenverGuy, Jul 18, 2020.

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  1. DenverGuy

    DenverGuy New Member

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    I'm new to the forum and first post.

    No option to enter a Lexus in my profile but I have a 2007 RX400H with 130k miles on it. In the last week the dashboard lit up and fault codes indicate a bad block 12. A new battery cost close to bluebook for the car.

    I'm looking at rebuilding the unit or purchasing a used battery. I've managed to find a couple of late-model Highlander batteries that are attractively priced but out of state. I am aware that the late model Highlander center battery pack would need to be disabled and repacked in the RX400H battery center carrier.

    One used battery is 2014 with 14,000 miles on it. It seems fairly priced until I found that it's been sitting in the yard for 850 days...Should I consider this? What damage has been caused to the battery from non-use? Can it be reconditioned to like-new or should move on?

    Thanks in advance.
     
  2. DenverGuy

    DenverGuy New Member

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    I thought I would post a follow-up as there doesn't appear to be much activity in the Lexus forum here. In my quest for information, I found quite a few threads by searching on "junkyard hybrid battery" and "salvage hybrid battery".

    Ultimately, I decided against the one above that has been sitting for 2+ years but have ordered a '15 with 56k miles from a Highlander that has been sitting for 4 months. I do plan to recondition the modules before installing them.
     
  3. ericbecky

    ericbecky Hybrid Battery Hero

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    Good info.
    Thanks for the update.

    Let us know how it turns out.

    What equipment will you use for reconditioning? A simple power supply? Or something fancier?
     
  4. DenverGuy

    DenverGuy New Member

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    My intention is to use a newer Hitech or Dynamite 4x100 charger if I can get one. Covid-19 seems to have done a number on the supply chain so we'll see.

    I'm totally open to suggestions...

    Thanks
     
  5. Agent00F

    Agent00F New Member

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    Please update with newest developments when possible. I might be in the same boat soon with similar year/mileage 400h.
     
  6. DenverGuy

    DenverGuy New Member

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    I finally got around to reconditioning the cells and it's slow...

    My learnings at this point:
    1. The charger is loud. I initially had it set-up in my home office for convenience. After my first conference call, that was a no-go. I moved the charger to an unconditioned storage area in my basement that had the added benefit of being around 65 degrees.
    2. Charging is fast, discharging is slow. I have a Dynamite Prophet Sport Quad 4x100 charger with a 5 amp discharge. Sounds great except in parenthesis, discharge is limited to 10w so you are looking a ~ 7 hours each discharge, ~ 9 hours total cycle time.
    I started the reconditioning on December 15th and finished on December 24th.

    Here are a couple of pictures of my setup:
    [​IMG] PXL_20201211_060055609.jpg As an aside, I ebay'd my charger and cables. Turns out the buyer was reconditioning a set of Prius modules, already had the same Prophet charger, and discovered the unit I had sold him had a bad fan, hence it being so loud.
     
    #6 DenverGuy, Jan 9, 2021
    Last edited: Jan 9, 2021
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  7. DenverGuy

    DenverGuy New Member

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    For the reconditioning, I cycled each module a minimum of 3 times at the max discharge rate of 10 watts to 7.2 Volts, charged at 3.5 amps to 7500 Mah. I checked temps pretty frequently. In my 65 degree room, I never saw a battery temp above 72 degrees.

    The '15 battery packs are 3 packs of 10 blades, the '07 are 2 packs of 12 blades and 1 pack of 6 blades. The packs are comprised of 2 stainless steel side panels with 8 stainless steel top straps and 8 stainless steel bottom straps blind riveted together. Reconfiguring the packs is straightforward but tedious.

    Tools needed to reconfigure:
    • Drill motor
    • 5/32 high-quality drill bits - I used 2 Viking Black & Gold bits - you have 96 rivets to drill out
    • Blind/Pop rivet gun - don't skimp on the gun if buying one as stainless rivets take a lot of force to install.
    • Center punch
    • Scotch 2242 electrical tape or equivalent - ideally in 1" albeit I used 3/4"
    • Foam tape - I used MD small foam window seal - I wasn't super pleased with this but I ordered some "soft" foam from McMaster-Carr that wasn't soft enough to be a suitable replacement and settled for the MD foam from my local ACE.
    • 48 - 5/32" x .362 18-8 open end, dome stainless steel blind rivets - I was unable to find these locally and ordered from McMaster-Carr.
    • 2 or 3 stout clamps to compress the packs while reassembling - the ones in my pictures were just adequate - bigger would be better.
    Since I wasn't reusing the '15 hardware, I disabled these first. I tried to save tape and foam tape combination. It proved to be futile and I cut and removed the foam from the side panel that I was removing. I then drilled the rivet head. This is pretty straightforward and as the rivets are stainless, don't skimp on your drill bits. All you need to do is remove the head by drilling the dead center of the rivet. If you've never done this or my description doesn't make sense, YouTube has a few videos on the topic.

    Watch for the centering of the drill and angle the bit if needed to re-center. You shouldn't need to drill more than 1/16" or si deep. I had a helper with a shop vac to catch the chips. Once the head is off, you should be able to drive the body of the rivet into the side panel. You can remove the bodies when you remove the side panels. I recommend drilling vertically as you will need to put some heavy pressure on the drill and it's easier to keep the bit centered in the rivet.

    I disassembled all the '15 pack, balanced the blades then rebuilt the '07 packs one at a time from start to finish. I used a single edge razor blade to cut the foam tape on the plastic blade separators rather than replace it. The process is pretty straightforward, after replacing the individual blades in the pack I riveted the bottom straps in place, then used the clamps to compress the pack and attached the top rivets. This takes a fair amount of force. From a timing perspective, my first pack to about 90 minutes, the subsequent two were less than an hour each.

    PXL_20210105_022438576.jpg PXL_20210105_025736962.jpg PXL_20210105_030157746.jpg
    Note the curve on the beam of the upper clamp in the second picture - it takes a lot of force to compress the pack for riveting.

    I'm probably stating the obvious, but gloves are your friend in this process. There are many sharp edges on the pack hardware. I also took many reference pictures prior to disassembling.
     
    #7 DenverGuy, Jan 9, 2021
    Last edited: Jan 9, 2021
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  8. DenverGuy

    DenverGuy New Member

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    As a caveat, I've skipped discussing all the reconditioning and safe handling aspects of this job as they have been covered by others better than I could and are pretty universal. Cardone has a good video on removing the battery from the car. I didn't completely remove the battery from the car but the steps to get to the battery, as well as the trim disassembly tips, are very helpful.

    Here is a picture as I am reassembling the battery: PXL_20210105_214151742.jpg

    If you go this route, looking for a late model wreck, here are some of the things I was concerned about:
    • How long the battery sat on the shelf - The wrecking yard should provide you with the VIN - in most cases, I was able to find wreck information including the car auction date and mileage - this didn't always match what the yard told me. I also found several low mile batteries that sat for years - the yards don't seem concerned about battery shelf-life.
    • By searching on the VIN (you could even buy a carfax), you can often find out where the car was registered and avoid areas such as Arizona - I was concerned about cars from hot climate and/or mountainous areas. Here in Denver, we seem to burn up batteries faster than flat land areas.
    It's just been a few days and a couple hundred miles since the install - so far all is good. Diagnostics are clean with internal resistance at 29 Milliohms on all 15 packs. The blades all tested at 6.9 AH (not that I believe the charger) or better.

    I appreciate all the direct and indirect help on PriusChat and will do my best to respond to any posts. The content on PriusChat has been invaluable.
     
    #8 DenverGuy, Jan 9, 2021
    Last edited: Jan 9, 2021
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  9. wcarr92

    wcarr92 Junior Member

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    Hi. I'm the guy that bought the Dynamite Quad Pro charger from DenverGuy (Not through PRIUSchat though). I wanted to follow up on his comments on charger noise. I had an existing Quad Pro already. DenverGuy is right about the noise. My reconditioning of the Prius pack is being done in my office so I can monitor progress. And he's right, the charger tested at 65dB (my existing one measured 60dB). I bought a couple NoiseBlocker BlackSilentFan XS-2 fans. Installed, they measure an astounding 49dB. Quite a difference. This was not a highly accurate noise test, but I did take several measurements before and after at 18" distance and got repeatable noise measurement results. I also found the spec sheets for the existing and the NoiseBlocker fans. Those spec sheets show similar values for noise and confirm that the new fans move slightly less air in CFM, but not enough for me to worry.

    Now I can have a decent Zoom call without participants complaining about my background noise. The fans cost under $15 each delivered. (thank you Jeff Bezos).

    And thanks to DenverGuy for his detailed write-up of the RX400H battery rebuild/reconditioning. Good luck to him!
     
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  10. Agent00F

    Agent00F New Member

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    Much credit to DenverGuy for uncovering this new method of breathing new life into 400h's and highlanders. Turns out Toyota just repackaged the same battery modules for the model refresh, and it just takes a bit of elbow grease to reconfigure them. The prices for these newer packs are still relatively low since any failure is still warrantied, so there's less salvage value, for now.

    I kind of wonder though if any aftermarket companies have been doing this to any extent, ie putting any of these newer cells in their remanufactured packs to replace bad ones. Because up to now we've assumed they just used old 2007 era packs, but perhaps some were aware the slices are the same (but the info never became public)?
     
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