DIY Grid Reconditioning Charger

I use a led driver to recondition my HV battery, so far with no issues.
It has a constant 350 mA current and 257v dc output.
I used 10 (1n4007) diodes in series to lover the voltage from 257v to 250v.
For who's interested It's a Mean Well HLG-80H-C350A available on ebay for less than 90 dollars.
In the black box I have placed the diodes.
It can be used for gen3 and gen2 prius.

 

I use a 12v 5a battery charger to run the battery blower, the pinout is available on prius chat, I can't post links, but you can search for gen 3 battery fan pinout.
To discharge the battery I use bulbs by following the Prolong procedure, basically I start with 400 w bulbs, then decrease the current by loosing some of them as the voltage drops.

 

Thanks for the feedback Fred_H , the charger has an aluminum case, it becomes warm, but never hot. I measure the voltage while charging with a meter and
the current is constant according to the manifacturer, so I haven't monitored that.
It is possible to change the current with a screw and the max output is 350mA. For the discharger I recycled a lot of trash I found in my attic Never throw away anything.
I'm very interested about the max voltage feedback, that's the bit I was mostly uncertain about so I have tried to stay as close as possible to the Prolong charger specs.

 

I performed 3 deep cycles, I've followed the prolong balance procedure and after 14 hours the peak voltage was 238.6, then after 10 hours it slowly dropped to 236v is this expected?
I can confirm the battery capacity improved, before reconditioning it went from 4 to 3 bars in seconds, while now it takes a minute or more.

 

I will try a 30 hours charge thanks for the tip edthefox5. I wanted to recondition the battery after I noticed a sudden capacity drop in August during my holidays.
I came down a very steep and long alpine pass in Austria the Gerloss pass, the battery was at 9 bars ( 8 + the 2 tips on top), I parked the car in full sun on a lake, than after 2 hours I went up a very steep road in reverse and fully loaded with bagage and 5 persons, the ice didn' t kick in to help as it usually does, strange I thought.
I drove a few km and the battery went back to 6 bars, but then after many km downhill I've never managed to get 9 bars anymore and it went from 4 to 2 bars in seconds, I thought I killed it.

Leaving a cold battery fully charged in the sun and then squize it to full load is really bad and I was fearing there was no way back, until 2 days ago the reconditioning reversed the capacity issue.

I still have to test if it goes back to 9 bars, but for that I have to wait until I drive back to an alpine road next month.

 

I did it just for 5 meters to get out of the parking, but it was a really steep off road parking spot.

 

probably not.

 

Probably not a biggie. According to wiki nimh cells need between 1.4 and 1.6v , the higher the current the higher the voltage, and 257v is between those values, but I' going to remove half of them and see how it goes, not all of them, because last time I did a 24 hour charge i have noticed some swelling which scared me a lot . After an hour the swell went away, is it expected?
I did 2 load tests on each module with a 12v 115 w bulb for 1 minute before the reconditioning and found that 2 and 12 were consistently the weakest, because the voltage drop was 0.30v on top of the others, but some modules gave inconsistent results.
Instead I would like to measure internal resistance of each module, deep cycle only the ones with the highest resistance and leave alone the other ones, this should bring more balance.