second prolong battery charger balancing

2012 prius 2 with 205K miles. Same battery with only a prolong charge done in 9/4/18
Started my second charge and balance today at 4:15pm. Voltage was 221 initially. Last time I charged on 9/4/18 I was only able to to up to 239 volts and it stayed there for 4 hours. I read that if it doesn't move after 4 hours you're pretty much done. I've read from some people to go up to 240. Should I wait as long as possible to get to 240? Or should I just wait the 4 hours of constant reading whether its 239 or 240? Please advise. Any contribution of information would be appreciated. Thanks in advance.

 

220v @ 4:15pm
233@5:15pm
240@7:25
240@8:20pm
241@10:35pm
241@11:30pm
241@1:30 am

I just checked and it's held steady at 241v for at least 3 hours plus. I plan to wait another 45 minutes and check on it. I hope it stays at 241v so I can get to bed. Also I believe the maximum voltage for a 2012 HV battery is 240 and I am a little concerned that it goes past the maximum. I've read of some Gen 2 people charging to 247v which is a little disconcerting to me. But I think they said after the long charge that it worked better for their battery and they got better mileage and for a longer time.
I appreciate your input Raytheeagle. I've seen alot of your contributions on this specific topic.

 

So went to check on charger at 2:30am and it was fluctuating between 241-242v. I think it will go to 242v and I will need to let it charge for another 4 hours to balance. I believe that's what the instructions say. I hope I'm not mistaken.

 

Went to check on charger at 6:20am and it showed 243v @ 6:30am. I was a bit apprehensive about leaving it on for another few hours and letting it get up higher. I read the the max is 240v for the Gen3.
So going way past doesn't excite me. I'll post back to review how the drive goes after this second charge and balance. Chime in if you have any suggestions or comments.

 

Ray,
Actually I only have the charger. My HV battery was strong and didn't show any signs of weakening in any way when I purchased the charger 6 months ago. I read on their website preventative maintenance is a good idea and I would agree. So I'm doing preventative charging and balancing. I've read on some posts that the person let the charger take the battery to 247v. What are your thoughts on this? Was it a good idea? What could be the result of this? I read your comment on it but it didn't say whether you felt it was bad to let it go to 247.

 

Ray,
Thanks for your feedback. Please explain 24 hours and 4 hours of "soak". Am I to charge 24 hours regardless of voltage reading and then "soak" 4 hours? Or 28 hours is max time to charge. Or Voltage at 240 and so proceed to "soak" for 4 hours? Please elaborate.
I plan to eventually buy the intelligent discharger and do a reconditioning. I feel I have another year before that may be needed. The charge and balance that I just did has improved the performance of my Prius. I will update as the weeks and months go but today's drive was better with more power and better mileage. I'm hoping to go to 250K and then recondition.
Please elaborate on 24 hours and then "soak". Thanks again.

 

At 242v I expected it to stop after 4 hours but it jumped to 243 at the last hour. I was worried and shut it off. Would you yourself have left it on for another 4 hours? Sounds like thats what the instructions say to do. But the chart also says that filling stage is up to 235v and balancing happens at 235-240v. So I was confused on should I have left it on for another 4 hours after it jumped to 243. You think I should have left it on for another 4 hours to balance when it went to 243?

 

I thought I was top end balancing when it was at 240 but it went to 241,242. I let it charge for another 4 hours at 242 and came back and found it jumped to 243. Should I have let it stay for another 4 hours to top end balance? I am thinking that when it doesn't fluctuate or move up for 4 hours that this is the balancing phase. But if it continues to move up, regardless of voltage, then it is still filling. When it stays constant at a certain voltage for 4 hours then it is balancing even if the voltage is as high as 247 as I've read other people's balancing experience.

 

Not sure what you mean my inconsequential. Like not needed? I sent an email to hybrid automotive and their response was that basically from 235 up I can let it charge for 8-12 hours more. They did say that to go up to 247 isn't unheard of and did not say that that was bad for the battery.
I think I had the charger on for maybe like 17 hours more or less. Per Hybrid I could have let it stayed on another 4 after it went to 243. I will wait another 4-5 months and perform another balance. The first balance got up to 239 and stayed there for four hours so I turned it off. This balance got me to 243. So maybe with each successive attempts it will push the battery up to a higher voltage and therefore more power? I have noticed better power on my acceleration. Like when it was new.
I've read a post about a guy suggesting one good charge, discharge and recharge is good enough. The logic makes sense. What are your thoughts on that and what have you done yourself? Thanks.

 

Thank you.