Dr. Prius Results Gen 2 2005 110,000 Miles

Thank you for your helpful responses! About blocks #1 & #14, I'll plan to recondition the pack with the prolong, and leave the modules as is for now.

How can I ensure 48 inch pound nut torque, would a torque wrench with settings be required or is there a way to confirm torque with a regular socket set?

I ordered the Ilsco De-Ox and returned the dielectric grease. I'm glad you suggested this because the bus bars keep re-oxidizing after I clean them.

I tried to restore the 5-0.8 nuts that go on the bus bars with the orange plastic connector, but found in related threads they are not restorable due to the 2 pc construction and the plastic ring that holds them together. I'm considering ordering these on eBay, they are listed as "Zinc" not steel. I confirmed with the seller that these nuts are non-serrated. Through quick google searches, I learned zinc is a better conductor than steel, but I don't know if that is a good thing regarding the function / purpose of these nuts. Would these work as replacements?

M5-0.8 Zinc Hex Flange Nuts Metric Class 8, DIN 6923 RoHS CR+3 | eBay

 

Progress update: The McMaster-Carr nuts for the bus bars, the torque wrench, and the De-Ox (worked amazingly at preventing re-oxidation after cleaning bus bars) have all arrived. Thanks everyone for these suggestions! I have the torque wrench set to 48 inch pounds, and want to confirm I have it set, and am using it correctly. I saw in another post that it is supposed to be "low value" torque on the bus bars, but it seems lighter than expected. After finger tightening, I start at 12 o'clock and turn until the wrench clicks, then stop, which lands me at about 2 o'clock. This is my first time using a torque wrench and want to confirm this is the accurate amount of torque. Thank you for your help!

 

I started the Prolong reconditioning process yesterday, and a concerning burning smell came off the top of the modules during the first discharge cycle (to 134) for my 2005 pack. First charge cycle started at 209v at 12:30pm and ended at 236v at 11:00pm. I started the discharge at 11:30pm and about 10 minutes into the discharge, I noticed the smell. I immediately turned off the discharger, and disconnected it. The pack is in my kitchen, where I have been working on it. I had previously cleaned the bus bars, put new nuts on the module posts (accurate to Toyota specs per this thread), and spoke on the phone with a Hybrid Automotive technician while I confirmed connecting the positive and negative terminals correctly before starting the first charge cycle, reinstalling the orange safety plug, and beginning the process. I have a 20 inch box fan blowing on full blast in the opposite side of the ECU into the vent under the modules, I also set another fan on the ECU side blowing onto the top of the modules for more cooling. There was no smell or issue during the charge cycle. I emailed the technician last night after I noticed the smell, but thought I'd report back here as well because I am worried about damage to the pack after having put a lot of work into it thus far. Has anyone had this experience and / or know of a resolution?

 

Smell update: I believe the smell is a normal omission coming from the Prolong Battery Discharger. Being my first time using the system, I did not expect there to be a smell similar to smoldering / burning, so I was definitely alarmed. Thanks to Hybrid Automotive's George on a service phone call today, and Jeff responding to a conversation here on PC, I was able to better understand the process and recognize what was happening. They referred to the rubber ventilation tubes as a potential concern, and bad module venting. I inspected and confirmed module alignment to be in sync across the modules how they fit together in staggered grooves, and removed the rubber ventilation, in case it may have been prohibiting module venting. Also, I learned there are resistors or coils inside the discharger that are turning on for their first times, and that, I believe, to be the source of the surprise odor. Upon restarting the discharge process, I put my face right up to the Prolong Discharger box vent, and recognized the smell from last night, luckily it seems that is where it is coming from, not the pack. Either way, to be safe, I now have two 20inch box fans blowing on the pack, and one smaller round fan blowing directly into the vent on the opposite end of the ECU. I also have the discharger on a plastic milk / vegetable crate, it was previously on a foot rest that had fabric on top, and may have warmed up on my last discharge attempt, adding to the smell coming from the discharger.

 

I've completed the final discharge cycle using the Prolong Deluxe Reconditioning kit, next step is the final charge! Is it best to charge immediately after discharging, or is it ok to begin the final charge after a day or two? I'm wondering if it is detrimental when time elapses at low voltage (expecting it to bounce back to 180ish currently) before beginning the next charge in the cycle, or if letting the pack bounce back on its own without immediately beginning charging is diminishing the longevity of the cells in the modules.

I'd like to do the final charge over the weekend, as I'll be home and able to monitor, as opposed to starting now, and leaving it charging while I go to work tomorrow and the next day. Maybe my hesitance to leave it unsupervised is unfounded, as I've read that others have left it alone during the charging cycle / intelligent discharge process, so long as charging does not exceed 48 hours. From all the notes I've taken, times I've reread the product guide on Hybridautomotive, and threads I've read here on PC, I don't think I've come across much discussion regarding wait times between cycles. Maybe because it's unusual to want to wait, but I'm kind of a safety nut. I did do the third charge cycle overnight, but I felt ok about it, in case anything went wrong, I was available at home.

I've attached a chart of the cycle start times, end times, start voltages, and end voltages. I recorded end voltages on discharge cycles as soon as I saw them, once I looked over at the discharger once it started beeping. It woke me up one time, so I was a couple minutes slow to get out of bed and into the kitchen to view the voltage and record it. Mentioning this because I did not see or record it hitting the target voltages, 134v, 101v, or 84v. I am guessing that it hit those targets or came close, the intelligent discharger went into idle mode, the voltage started bouncing back, the beeping started, then when I got there to the discharger what I saw was a "bounced back" voltage. On the first discharge cycle, I assumed something was amiss, and clicked 134v again to continue it discharging, but stopped it after about 10 minutes, because I realized, the system probably knows better than I do. So, on the second and third discharge cycles, I didn't discharge more, I just put my faith in the technology.

 

Thanks guys for your replies and help understanding the process.

I monitored 2-4 hours that it was stable at 236v, reflecting now, and considering your experiences, I agree about the charge times being short. The guidance I received from the HA service rep over the phone was to charge "6-8 hours, maybe longer, no more than 48hrs" on the 1st, 2nd, and 3rd charges. He said (and the product guide chart lists) to watch for when peak voltage (235-240v) is reached and when the reading was stable there, to stop. From my conversation with him, my previous understanding was that the final charge was the "most important" to go for longer (24-48 hours). I think I underestimated the ability of my pack to make it further than 236v, as I believe the pack to be 10ish years old. I was off base, I believe, and under the impression, after that phone call, that the final charge was the most important, all parts of why I settled for these charge end voltages. Next time, I will do 24 hours minimum (unless stable north of 240v for 6hrs before 24hrs) each charge cycle because I do want to reach that maximum capacity and am hoping to see full green bars on my MFD. I'll post Dr. Prius readings of my first test drives in the coming week(s), here's hoping to getting back on the road with no issues!

I appreciate that info on the intelligent discharger wait period, that definitely explains why I never saw the target voltage displayed.

Great info about NiMH and SoC when stored! I just plugged in the discharger, leaving it in system idle, and see a stable 180v reading for the last 30 minutes. Definitely a way to stay assured, and also learn if there are bigger fish to fry, hopefully there are not any more fish here haha.

Thanks for describing your charging and discharging process, it's helpful, especially when time is a major factor in the reconditioning process. Thursday is the last day of the school year here, so I'll be able to begin monitored final charging as early as Thursday afternoon, into the weekend.

Thanks again for the reassurance about the process, helping alleviate concerns, and providing your expertise! I may be able to help my sister with her 2006 in the future, thanks to everything I've learned here!

 

I'm looking forward to having that much healthier battery! Thanks for the note about not getting too hung up on getting the charge the highest it can go, and for the heads up about going into neutral and running the AC, I've made my notes and will definitely do this once I reinstall.

Posting progress here;



I've been monitoring since starting the Final Charge yesterday morning. It was making steady progress for the first 12 hours but has been lackluster since. I'm at around the 30 hour mark now. I was planning to go the full 48, but it has steadily dropped from 238v to 236v over the last 6hrs. Is this a sign that it is at its max, could it be potentially problematic to continue, or should I power through to the 48hr mark tomorrow at 9:30am.?

-Side notes between the ----- to the right were just for me to compare gaining 11v in 12 hrs between 12p & 12a vs. the 2v gain between 12a and 2:30p.. which has now turned into a 1v gain over 16hrs.

Update: Currently oscillating between 236v & 237v at 5pm. It looks like it is trying to hold at 237v. Maybe this means the earlier stretch of stable time was a normal lull, and to keep powering through.

 

@jerrymildred and PC team thanks again for the help on this. Ok, yes I agree, the discharger will tell me exactly what the voltage is, even though the AV method is a good way to do it, since I have the intelligent discharger, I could be exact with it. Do you mean run it down to normal operating range like 220v-ish?

I'm going off of the Hybrid Automotive charge voltage table, being that they list normal operating range for Gen 2 to be 202 - 235v. Also, I've believe the fluctuating up and down of the voltage was balancing, which I think I'd read here somewhere on PC, but hadn't remembered today. Per Hybrid Automotive's charging product guide;

"Once the battery becomes ‘full’ the balancing process will begin. During the ‘balancing’ phase you will most likely see a steady voltage reading or a very slow oscillation of voltage – perhaps a 1-3 volt swing over several minutes. This means the battery is in the balancing phase. The initial balancing can take 4-12 hours after the filling phase is complete. Subsequent balancing sessions will likely be much shorter, perhaps 4-6 hours after filling is complete. During balancing, each individual hybrid battery cell is rising to a true 100% state of charge. As an individual cell reaches its peak voltage it warms slightly, then the voltage drops as it converts the excess charge energy to heat, then the cell cools and again charges to 100%. The process is repeated over and over."

It's been at 238v for about 2 hours. I'm thinking let it run through to the morning and stop this final charge around 8am. The reconditioning product guide says to run 4-6 hrs after voltages stops rising;

"5) Charge and balance the battery pack one last time. Let the charger run for at least 4-6 hours after the voltage stops rising to ensure the pack is fully balanced."

 

First and foremost, thank you to everyone here for your continued advice, counsel, and patience. I could not have done this work without you. Not only did I save on costs vs. other avenues of replacement / maintenance, I've learned a lot, and no longer believe working on a Prius is only for astronauts. I'm excited to announce that; Houston, we have liftoff!!! The car started and ran well!

To follow through on the final charge discussion, the pack reached and held at 239v at 47hrs of charging. I discharged with the intelligent discharger down to normal operating range 223v, there was a rebound to 225v. I let it rest for a couple hours while I reinstalled the pack, and set up the prolong charger harness in the vehicle.

Upon initial start up; no error codes on MFD or dash! Before, it was the christmas tree effect with the big red triangle, red car on MFD with a slash through it, and all the check engine lights on the dash.

The MFD showed steady 6 blue bars! Before, when I started the car it showed 1 purple, rapidly grew to full green, and rapidly dropped over quick intervals on short trips.

I took an initial Dr. Prius reading in my garage once I started up, SoC showed 58.50.

I did a 30 - 40 minute test drive around town and on the freeway. I went to the gas station where I put some air in the tires, the Michelin's on the car are rated max psi 44. I filled up and documented, as I'm planning to track MPG on Fuelly. Then I drove on the 101 for a good 20 minutes. It's been over a month since I drove. It felt good to be back on the road, although I seemed to notice more tailgating and crazy drivers than I remember, or maybe I'm out of practice and that's how it's always been lol. Average speeds around 55 - 60 mph. Came back into town and went to the grocery store and the hardware store. After the 22 mile test drive I averaged 55.8 MPG. I was happy to see that, even though this is not an absolute indicator of long term overall MPG, monitoring only one short test drive at conservative speeds, it was assuring to see.

After the test drive Dr. Prius showed SoC 64.00.

I'll continue to monitor and document, in hopes to record stable and continued battery health. Prolong suggests reconditioning at 6 month intervals, so I'll plan on that for January. As always, your insights and experience are much appreciated. Thanks again!

 

I made a slideshow video overview of my reconditioning process;

Hope it helps if anyone is searching for resources or clarifications in troubleshooting similar problems.