Reconditioning Experience with Hybrid Automotive's Prolong System

60 minutes should be fine for a wait period, but I’m a wait more type.

Better safe than sorry, especially if you’re extending the holiday weekend a day.

 

Agreed, Ray.

Charge#3 data...

Sat 7pm, 115V, current varies
Sat 8pm, 208V, 0.358A
Sat 9pm, 218V, 0.358A
Sat 10pm, 222V, 0.358A
Sat 11pm, 225V, 0.357A
Sun 12am, 226V, 0.357A
Sun 1am, 228V, 0.357A
Sun 2am, 228V, 0.357A
Sun 3am, 229V, 0.357A
Sun 4am, 230V, 0.357A
Sun 5am, 232V, 0.357A
Sun 6am, 233V, 0.357A
Sun 7am, 234V, 0.357A
Sun 8am, 235V, 0.357A
Sun 9am, 236V, 0.357A
Sun 10am, 237V, 0.357A

 

Remainder of Charge#3...

Sun 11am, 237V, 0.357A
Sun 12pm, 238V, 0.357A
Sun 1pm, 238V, 0.357A
Sun 2pm, 238V, 0.357A
Sun 3pm, 238V, 0.357A
Sun 4pm, 238V, 0.357A
Sun 5pm, 238V, 0.357A

Switch to Discharge#3...

Sun 5pm, 236V, 1.538A

 

Rest of Discharge#3...

Sun 6pm, 216V, 1.540A
Sun 7pm, 207V, 1.542A
Sun 8pm, 203V, 0.500A
Sun 9pm, 197V, 0.489A
Sun 10pm, 170V, 0.314A
Sun 11pm, 133V, 0.250A
Sun 11:30pm, 106V, 0.237A - Voltage dropping rapidly, missed 84V termination target

Switch to Charge#4 (final)...

Mon 12am, 147V, variable A - Voltage rebound from 84 to 147 in less than 30 minutes
Mon 1am, 208V, 0.358A
Mon 2am, 218V, 0.358A
Mon 3am, 223V, 0.357A
Mon 4am, 225V, 0.357A
Mon 5am, 227V, 0.357A
Mon 6am, 228V, 0.357A
Mon 7am, 229V, 0.357A
Mon 8am, 230V, 0.357A
Mon 9am, 231V, 0.357A
Mon 10am, 232V, 0.357A

 

Almost there.

 

Continuing final Charge#4...

Mon 11am, 233V, 0.357A
Mon 12pm, 234V, 0.357A
Mon 1pm, 235V, 0.357A
Mon 2pm, 236V, 0.357A
Mon 3pm, 236V, 0.357A
Mon 4pm, 237V, 0.357A
Mon 5pm, 238V, 0.356A
Mon 6pm, 238V, 0.356A
Mon 7pm, 239V, 0.357A
Mon 8pm, 239V, 0.356A

Getting there, Ray.

 

Final data from Charge#4...

Mon 9pm, 239V, 0.356A
Mon 10pm, 239V, 0.357A
Mon 11pm, 239V, 0.357A
Tues 12am, 239V, 0.357A
Tues 1am, 239V, 0.356A

End Charge#4.

Battery voltage at 239V for 6 hours, with no perceived fluctuation. So, I considered it balanced and finished.

HV battery has rested overnight, almost 9 hours now.

While reconditioning, I did some other work on the car (replaced serpentine belt, clean and lube front brakes). I have to put it back together before it's usable. I'll check Torque data and have more to report later.

 

Update + Thanks

I used the Hybrid Assistant App to monitor the battery temperature periodically both during charge / discharge cycles. The highest temp I noticed was 95 F which, per George from HA was under the 100 F maximum they recommend. However, while monitoring the traction battery temps, I noticed that the battery SOC reported by the app was often way off the mark. For eg. when the battery was at 338 V I know that it is almost 100 SOC but the app would show some arbitrary number and if I keep the app running the SOC on the app would slowly creep upwards.

When I finally finished the last and final soak charge/balance the SOC per the Hybrid Assistant app was very low - in the teens or maybe 20% or so. I let the car sit for about 3 hours before starting to drive but noticed upon starting that on the car display it was showing as very low battery. I started driving from home, but after seeing this low battery indication, I got alarmed and turned back home. Reason for my being alarmed is that I remembered reading a warning from either @Raytheeagle or @jerrymildred that if the car tries to charge an already FULLY soak charged battery, that is a recipe for disaster. Remembering this dire warning I immediately turned back home, parked the car and removed the terminals from the 12 V battery for 5+ minutes. Upon reattaching the terminals several ECUs got reinitialized and the battery showed as full.

I realize that I was a hair's breath away from destroying my still healthy and in good condition traction battery. So a BIG THANKS to all the folks here at PriusChat who keep reminding others of this aspect when reconditioning the battery packs.

That's all for now....

Thanks again.

Hare Krsna
Sridhara-syaa dasa

 

If you let it rest for three hours after the final charge, you were probably OK. But better safe than sorry. Lots of people disconnect the 12V during a Prolong session to keep it from running down if any lights get left one. Apparently that has the added advantage of forcing the car to update its SOC information. Makes sense!

 

That works for a Prius but remember this guy is not working on a Prius, he’s working on a Highlander. Any of his results should be disregarded for obvious reasons.

 

Another oprion is to keep a battery tender on the 12v while doing the Prolong sessions. I usually wait at least 5 or 6 hours to start the car when I'm done. One of the more knowledgeable members here also suggested using the air conditioner on max when you start it up to run the SOC down from 100% and slow the charging process that first startup..

 

Thanks for the reminder it's a Highlander. I was typing while you were posting and I had missed that.

 

It didn't say Highlander and this is a Gen 2 forum. Just figured it was a Gen 2.

Either way, the principles should be the same whether the batteries are the same size or not.

 

I don’t think he mentions it’s a Highlander past post #970.
I agree the principles are the same but I don’t know if the capacity is the same.

 

Here is that photo I mentioned...

 

Yeah,

There's no way he's working on a Highlander. Totally different battery and it uses 9.6 volts modules and is just a bit under 300 volts IIRC. . If he's really using a Prius Prolong Charger on a Highlander, the results would be less than satisfactory...

Nevermind....I confused two posters, my mistake....Dan and Sonjay are different posters....old age gets me again...

 

It's been about 5-6 days and 250 miles since reconditioning the battery. I haven't studied the before and after data closely yet. I'll do that in another week or so of driving.

So far, I haven't noticed a difference in behavior or performance.

Using Torque, I measure:

HV Battery State Of Charge
All 14 block voltage measurements
All 14 block internal resistance measurements
NiMH Delta voltage
MPG (average)
HV Battery temperature (3 sensors)
HV Battery intake air temperature
AUX Battery voltage

 

I can say after my last recent second reconditioning the battery was like new no more purple and alot more power. The first recon lasted at least a 14 months. The seat of the pants butt data is very noticeable.

Find a nice flat straight stretch of highway without alot of traffic. Get the car up to 60 miles an hour and zero out the recent mpg on the MFD. Set the cruise control. Drive at least 3 miles in CC. SAfter the 3 you should see at least 55 mpgs. Anything less than that you may have an issue.

How many miles on the car. I have 135K.

 

Thank you for the suggestion, edthefox5. I will check the highway MPG next week.

My '07 currently has 91K on it. It lived in the Texas heat, no garage, for 11 years until I bought it Sep '18. The previous owner only drove it 2000 miles in the year before I bought it. With the age, heat and infrequent use, I thought the battery would benefit from reconditioning, even though it appeared pretty healthy (45MPG average with combo highway/city driving and very little voltage deviation between blocks). I'm in the measurement and observation stage of evaluation. I wonder if my battery was actually healthy and reconditioning, while perhaps benefiting the battery, did not affect the battery in a way that I would notice/measure. Again, I'll give it some more time/miles and report back with before and after reconditioning data. I know very little about the science and what conclusions can be drawn in the end, but I will do my best. Hopefully, more knowledgeable folks here can put their 2 cents in and other members can benefit from the data.

 

Indeed, the Prius normally uses only 40% of the nominal battery capacity. In theory, some cells could be degraded by as much as 50% without major changes in operating behavior.

If some cells are degraded to the point that they are being pushed to and beyond their limits, they are in imminent danger of failing completely. That is why it is often recommended to at least do top balancing on older batteries, even before there are any signs of trouble.