Would it be worthwhile, with a battery exhibiting no problems, to disassemble, reorder the cells, ie move the outer to the middle and vice-versa? Clean up the bus bars. Any suggestions for procedure, details, and an interval for doing this? Are there other checks worth doing at the same time? Or let sleeping dogs lie?
If you're out of warranty, you should open it up and clean off the corrosion from the bus bars, clean the cooling fan. I don't think you'll need to shuffle the modules, that would just require a lot more work. These packs are not light, if you have problems lifting, you might not want to do this. Although cleaning the bus bars might be possible without removing the pack
You could do some live monitoring/recording of hv battery block data to get a baseline of how things look now. Then do some preventive maintenance with a few cycles of charging/discharging a couple times of year. You could once a year take the cover off the pack just to peek in and do a quick inspection of things. (buss bars, torque specs, voltage sensing wiring, etc) If the data provided insight that would make you think there are bigger issues, then you might dig into the pack. But I wouldn't start tearing things down just for the heck of it. Could be extra work for little if no improvement return.
ML, This is something I've been wondering about also. There is such selection of apps (especially for android phones) that we can now watch and graph the HV battery blocks in real time. When I built the HV battery for my car and my son's, I saved all the cycle testing data for each module on an excel spreadsheet. I also documented which modules were placed in each block. I've started load testing my battery and my son's battery each month using my Galaxy S3 phone and the Hybrid Assistant app. I can then screen capture the graphs I'm interested in, transfer them to the laptop, and then add them to the spreadsheet with any comments. Hopefully, over the course of time, I'll be able to see any trends developing that could indicate it's time for a refresh, a rearrangement, etc. I'm sure there's easier ways to do it, but I'm still a novice on the phone app thing. The app I use has a section for exporting data but I just haven't gotten it to work for me yet. Unfortunately, warranty considerations have to be included. I think for anyone not under warranty, once a battery pack gets to the 5-6 year old range, it would be prime time to start a pm program (but only for DIYers). It wouldn't be hard or expensive to get a spare sensor harness and bus bar harnesses, have them cleaned, prepped and inspected ahead of time. Pull the battery and fan once a year for cleaning, inspecting and swap out the harness and bus bars and even new nuts if needed. Once the old bus bars are removed, it would be easy to inspect the terminals/modules for any evidence of leakage/corrosion/etc. Any leakage tends to show up as green liquid on the plastic directly below the terminal. If live monitoring/graphing shows the middles are getting weaker, swap blocks 1-7 with blocks 8-14. (swap 1 with 8, 2 with 9, etc) so all the outer blocks will now be on the inside. Almost like rotating tires.
Regular charging/discharging is the least invasive and require the least amount of labor. Especially if you install a harness the first time you do it. Plus it would likely take care of blocks that seem to be slightly drifting out of balance compared to the rest. The more you mess with the blocks the higher likelihood you may make a mistake. (cross thread, break a terminal, strip a bolt, etc) "No good deed shall go unpunished."
I wouldn't bother to do more than fan cleaning and putting few drops of oil to its axle under the sticker at its back. Mine became quieter after the cleaning and the oiling. I don't think cleaning the bus-bars has any effect if they're not super corroded. Usually the copper under the nuts is still shiny. I would hook up the Techstream/Hybrid assistant and check the voltage differences between the blocks, if they're not minimal, I would give the bus bars a good bath in some acid (vinegar, 12v battery, etc) and rub them with steel wool or soft bronze brush (like I did in post 17).
Yeah I've done fan cleaning, a couple of times now. Looked pretty good, just a little fine dust on the fins.
+1. Our 2010 now with almost 168 k miles exhibited very little signs of degradation, but I had @jeff652 install a Prolong Harness and now I perform preventative maintenance . I have noticed improvement in the length the battery lasts, more charges to 7 bars and less cycling. While there is some investment, IMO it was worth it. I share the charger / Discharger with another member here, so the costs are reduced . I would take this route if you want to preventative maintenance your battery .
Cargo culting again I think: preparing for things that might never come. Though, time is maybe more critical than miles with the battery?
You got an 8/100 warranty up north? I waited until I was 1 k miles before the end of our battery warranty (149 k miles) before the harness install . When the wife’s RX450h approaches either limit (8/100 for the RX) I will look @jeff652 up for another install. But that’s another 7.5 years or 96k miles from now.
Allow me to remind you of the following: 1) If it ain't broke, don't fix it! 2) If it ain't broke, fix it until it is broke! …and let us not forget the Software Engineering Rider: 2a) If it ain't broke, it doesn't have enough features! …learn these well, young Mendel!
Isn't fan cleaning quite a process? (At least when I watched NutzAboutBolts' video). I definitely would like to clean the fan as I suspect mine probably has some accumulations.
It's not too hard. The one variation I would do from the video is to not remove the rear seat. There's a single bolt you need to get to, in vicinity of the inlet grill. By pushing a gap between the seat and back, with a light and about 9" of ratchet wrench extension, you can get a socket on the bolt (12 mm head). Just don't drop it, lol. Everything else is pretty much follow-your-nose. The frontmost portion of the hatch floor clips to the top of the battery with strong fasteners, just needs careful prying. I left most of it's fasteners off, and next time was much easier. Yeah, follow the video, take your time. It's not necessary to pull the fan right out either, it can be cleaned in place.
Guess I'll wait til summer. Hmm... not sure how long my extension is but dropping the bolt will be my biggest worry.
I used a 6" plus 3" extension, and it's just possible to sneak a hand in too, to grab the bolt as it comes loose, and vice versa when installing. It'd help to have another person hold the light and maybe kneeing the upholstery out of the way, but it's manageable.
