Help need with Prolong discharge process

@jerrymildred has the simple discharger. Either he or @jeff652 can advise you on this.

 

Yes. I checked the voltage readings every 15 minutes and recorded the values to compare to the chart on their website. This let me see the performance improvements through the process and was also a good reminder of when it was time to pay closer attention as change over points approached.

You should let the battery rest after the reconditioning for at least an hour before driving. According to prolong, disconnecting the 12v before restarting the car will prompt the battery ECU to perform a recalibration.

 

Be sure to let the battery rest. @jerrymildred got impatient one time and ended up having to replace the battery.

 

I did one cycle/day which roughly broke down into 18 hr charge, 4 hr discharge with a little breather in between each. I did the full 3 cycles over a 3 day holiday weekend.

 

Here's the link to the discharge voltage table.
Prolong Simple Discharger User Guide – Hybrid Automotive
Just use the column for the 04-15 Prius. I copied it and printed it out so it's on paper in the drawer with the charger.
Keep a close eye on the voltages because the lower it gets the faster it drops.

As to killing my battery, I started it up and test drove it too quickly after a final charge and got a failure code on one cell. The device was fine; my patience was inadequate.

 

Not my best day.

 

Because the HA information tries to cover all things for all cars, I find it becomes confusing, so like @jerrymildred, I copied only the relevant info as it pertains to the Gen II Prius.

In addition, I found it much less confusing when I separated (in my head) the discharge termination voltage from the light bulb wattage swap voltages and thought of them as two distinctly different things.

So I came up with with:


Discharge Termination Voltages:

Code:

First Discharge       134 V    (0.8 V per cell)
Second Discharge       84 V    (0.5 V per cell)
Third Discharge        17 V    (0.1 V per cell)

Light Bulb Wattage Change points:

Code:

(Approx. Minimum Voltage)
200 W Light Bulbs      196 V
 75 W Light Bulbs      140 V
 25 W Light Bulbs      Below 140 V

So, first discharge: the aim is to stop at 134 V. Begin discharge with 200 W bulbs until 196 V, then change to 75 W bulbs. At 140 V change to 25 W bulls. Terminate when 134 V.

Second discharge: the aim is to stop at 84 V. Begin discharge with 200 W bulbs until 196 V, then change to 75 W bulbs. At 140 V change to 25 W bulls. Terminate when 84 V.

Third discharge: the aim is to stop at 17 V. Begin discharge with 200 W bulbs until 196 V, then change to 75 W bulbs. At 140 V change to 25 W bulls. Terminate when 17 V.

You may want to do only two discharges this time around (due to your time constraint) and then run the car for a week. If you wish you can do a further round, this time doing the three cycles.

I found I need 3 full days to do the 3 cycles so starting on Friday evening I would finish on Monday evening.


I hope that helps a bit.

 

I've never thought to do this but to possibly speed up the two cycle reconditioning process, you could force charge* the car up to green bars before throwing it on the grid charger. This should shorten the first charge time appreciably.

*Force charge: with A/C off, parking brake on, left foot firmly applied to brake pedal, place Prius in D (not P or N) and floor gas pedal till battery icon reaches green bars.

 

By force charging, you probably would shorten the charge time by 8 hours. I would only do this if you're really short on time

 

Nice job! Thanks for posting, @dolj ! There are many threads addressing the Prolong/BulbDischarger confuserization, including a couple from me (see threads passim). (To the OP): my solution was to give up the gin for a couple of weeks, and investing in a NintelligentDischarger - that was a couple of years ago, and so far I'm pretty happy with the results! (yup, I realize there are nay-sayers in our midst (you all know who you are! …but to them I say "Go and boil your heads!" bloody unbelievers!) (check out my "fuelly" results, best journey recently hit 79MPG (AVG), overall ~44MPG, and SoC ~67% (best seen = 81%) (…but YMMV! )

 

Did this last weekend thinking I would need the vehicle before the next day (afternoon).

Started a simple top balance at 10pm with the hv battery around 60% and forced it up to 80% in about 1 minute (should've tried this at the lowest RPM possible, as I might've heated the pack unnecessarily).

Turned it off and without waiting turned on the charger, battery read 238v which I thought was high at 80% charge, then it went up to 239v nearly right away, it saw 242v while it cooked for about 8 hours, the last couple of hours slowly saw the voltage drop back down to 238v before I called it quits. Wasn't sure about leaving it on longer while the voltage kept dropping.

Total charging time 10 hours, add another 2 hours to cool down before readying -then shifted into neutral and turned on the AC to bleed a little off the top.

Next time I will do the slow and steady process like once before, as now I am worried about any potential damage to the battery by force charging.

Wondering if my 238v at 80% could be related to what @dolj was seeing with blocks going over 17+ volts while force charging various used battery packs.

 

Just make sure you are on top of the 'bulbs' while discharging, as going too low can take a decent battery and turn it into a fixer.

 

@jeff652 is the most knowledgeable since he made the equipment.

 

Were you watching the unit right when it shut off? We added a seven minute cooldown so the buzzer does not go off until seven minutes AFTER the discharge is complete. This is a lot of time for the voltage bounce back to occur. If your above voltage readings are when the buzzer sounded or after, then the readings would make sense as the voltage has already rebounded when the load was removed.

I made a video to show this but haven't had a change to upload it yet as I've been swamped getting the ProlongPro Discharger done. We finally resolved the last remaining issue today (Yay!) so hopefully in a couple weeks I'll get the videos online.