Dr. Prius Results Gen 2 2005 110,000 Miles

Posting to update and keep a journal / timeline of the journey of the Prius! About a year and 20,000 miles later we are still on the road!

January 12th, 2021 I charged the battery with the Prolong Charger (6 months after replacing modules / blades and reconditioning). With the charging assembly still attached to the battery, this follow up process of charging each 6 months is so much easier than before!

On that first go, after confirming with a tech from Hybrid Automotive, I left the charger plugged in and running for 23 hours, as I noticed the charge stabilize for 2-3 hours at the end of this initial charge cycle.

6 months later for the second charge, I did on June 14th. Just getting around to posting about it now. I charged for 24 hours. For anyone who hasn’t done this process and for next time when I read this in 6 months to remind myself, the 12V battery does not need to be disconnected during this process. It would only be important to disconnect it if the door was open and / or a light was on that was draining it.

The tech at Hybrid Automotive advised me that the 12V is not affected by the Prolong charging process. Since I am, admittedly, not an electrician and don’t have the professional experience with how the HV and 12V processes overlap, this is an important distinction for me to make for myself in the process to be sure I am doing this correctly and safely.

Here’s the Dr. Prius readings for the first drive after the charge. At the end of the charge the Prolong Charger read; 239V 343A.

Cheers Prius Fam, we’re still on the road!

 

Hi Prius family! Back at it again -- Red Triangle came back a week ago so this time I'm load testing and would like to check in for your feedback before I reinstall the battery.

I replaced 4 blades this time, 7, 8, 13, and 22 are the new ones. They're already in the pack and I made those replacements based off of Dr. Prius readings. I actually replaced those 4, then reconditioned with Prolong charger and discharger, ran the full cycle and 40 hour final charge. Let it sit for two days. Thought long and hard about confirming my work with load testing as I wanted to make sure that I replaced the right blades and double check my work with load testing this time so I don't end up missing a weak blade and having to do this again sooner than necessary.

How do the numbers on the attached spreadsheet look good to you guys? To my surprise, one of the new blades, #8 showed the greatest voltage variance of the whole pack, is this something I should be concerned about?

I load tested each blade for 60 seconds. First recording the static state, then where it registered on my multimeter after 60 seconds. I used a 50/100W sealed beam headlight gator clipped to multimeter leads. It's my first time load testing so I appreciate your advice on any other data I should be going for to determine if these blades are good to go / your suggested methods on how to best perform the tests for best results.

Thank you,
Sean

 

Thank you for your responses!

Albert, I will have to try that method once I reinstall. Thank you for the suggestion. I like the idea of testing under reversing and full acceleration to monitor performance in order to identify weak links.

Mendel, yes, I've called these things so many different names - to be clear, yes blades = modules. I'm trying to confirm if I replaced the right ones or if there are any issues with the voltage differences that display after load testing. I've heard of people "shuffling the deck" to match strength of modules / blades and pair them together in their respective blocks. Would anyone be able to share experience on that or suggest that I do that given my data?

Nancytheprius, thanks for joining the thread and helping out, any advice would be much appreciated!

Best,
Sean

 

WOW! @nancytheprius thank you so much for taking the time to match the modules up and share that with me! Modules 8 and 28 are both fairly new, 8 from when I replaced 1 or 4 last week, and 28 is a new one I put in 3 months ago when I swapped a couple out. I'm going to give the reshuffle a shot! I did not reshuffle or pair the blocks like this the last two times I've replaced modules so I'd say it's definitely worth a shot in hopes that it will help the fix last longer this time. Thank you and any other eyes on the prize here that have suggestions are always appreciated!

For measuring milli amp hours, I believe the prolong charger has a reading for sure that displays that, but it's for the entire pack. Is there a way to measure modules mah individually? I will probably just go with the info I have currently but it'd be good to know for the future.

 

@jerrymildred @fotomoto @dolj @Mendel Leisk

Just completed the reshuffle last night to match the data @nancytheprius provided. I emailed Hybrid Automotive asking if I ought to recondition the modules in their new order, and the tech said that I should not shuffle the pack.

I mentioned a few folks who had been on this thread before to see what your thoughts are. I know I've heard it mentioned here many times about reshuffling and reordering modules to match. So I went for it as @nancytheprius awesomely put a matching list together based on my data for me.

I reshuffled them last night and could install the pack back into the car tomorrow, but the Hybrid Automotive tech made me kind of nervous about it. I could put them back to their original order, as I had them numbered, not sure what to do at this point. Here's what the tech said;

"Oh no, shuffling the modules is a really BAD idea, modules work in pairs you will have a lot of problems and if you dint a identify the modules you will have a never-ending stream of problems with the pack, doing a reconditioning after replacing modules its good and will not harm the battery, most likely it will not gain more from the process but at least they will balance, the thing is that modules have Amp-hour capacity and the capacity has to be almost the same from the two modules in the same pack, shuffling the individual modules around will really mess up the battery."

 

Thanks @Albert Barbuto and @nancytheprius for your responses. I agree the tech's response is confusing and that discharging and charging is a best bet to promote longevity of the modules. Indeed new modules introduced the the pack changes the order. @Albert Barbuto thanks for sharing that data. When you say cycling, could you explain a little more what your process is? I see 12 discharges listed, are you charging the whole pack again after each discharge? Is this 12 discharges and charges of the entire pack? In my experience, this could take a week or two all together, as my usual reconditioning cycles of 3 discharges and 4 charges usually take around 4 or 5 days.

In the end of this recent reconditioning cycle, I opted to go back to the original order of modules, with the four new modules added into the pack. Reordering them I broke a couple temperature thermistors off the bottom of the modules (DOH*) but luckily a helpful Prius Chat member was able to send me a couple of replacements to splice in. Pack is back in the car and running fairly smoothly for the last couple weeks. I say fairly because there have been a couple of curious displays of blue bars running up and down on the MFD. Watching the activity on the Dr. Prius App it shows a higher discrepancy in voltage variance (picture attached) and then a more mild discrepancy as I keep driving it seems to even itself out. Any feedback on the reading would be appreciated.

Hoping for the best and expecting I'll probably need to pop another 4-8 modules in sometime in the hopefully not too soon future. At that point, I'll be close to having replaced the entire pack with new modules.

 

Hello again! 3 questions

1. How can I identify why my temperatures are running higher?

2. How can I better understand what everything means in the Hybrid Assistant report? Also, can this be transferred to my computer? I haven't seen an export option in the app.

3. Block 5, is it bad enough to warrant replacing right now? (hybrid assistant picture attached) It didn't appear as bad as the previous 4 modules I swapped out during this repair, meaning, hybrid assistant did not implicate it as requiring attention until now.

Just replaced 4 modules and reconditioned the pack this week. Had a red triangle moment last weekend. Just put everything back together, started up no triangle, which is always a good feeling, but seeing temperatures higher than normal;

Typically they read in the 70 degree range, currently all three are in the 100 degree range. Not sure if this is due to the reconditioning process I completed over the week or if it's the warm weather, or something else. Temperatures stayed consistently around 100 degrees for the three temperature sensors on my first 15 minute test drive. It was around 90 degrees today ambient temperature but during the test drive it's around 60 degrees outside. (side note I cleaned the HV cooling fan thoroughly about 2 years ago... I don't have animals so I don't expect that it got too dirty or clogged at all)

I had been using Dr. Prius, but recently resurrected an old android phone to use Hybrid Assistant. Getting a wealth of information from the reports there but I'm also looking for a walkthrough for better understanding all of the report information. Does anyone have a tutorial for reading the reports / downloading them? I'd love to share the full report here for feedback as well

Thank you,
Sean