2011 Prius Battery Reconditioning? - Sitting for 4 years

Gentlemen,
I have a line on a 2011 Prius that has been sitting behind a repair shop for 4 years. It has a rod through the block and the customer declined to get it repaired. I found the owner and am currently working on a deal to purchase the car. I am quite mechanical and do all of my own work as a general rule. I'm not afraid of the engine work/replacement, but don't have a ton of experience/background knowledge on the battery side of things. I have a couple of questions:
1. I've read a bit about battery reconditioning. Is it reasonable to assume that I could recondition the battery in this car? I have to assume it has been fully self-discharged by now. It was reportedly in perfectly good working condition when the car was parked.
2. If this battery can be reconditioned, what equipment should I consider using? Is the Prolong charger/discharger the way to go, or is there something else out there? Is there a DIY method out there that would be worth doing?

I have another parts Prius (same situation) with a hybrid battery that has been sitting for about 2 years that I would want to also recondition if possible, as well the battery in my current daily driver (2013 Prius). As such, it's a little easier for me to justify purchasing a system. I'm just not familiar with the current options and capabilities of these systems.

Thanks in advance for your help.

 

Thanks for the replies so far, guys. I ended up picking the car up this weekend. After giving it a good wash and vacuum, it looks like it's going to be a pretty decent car. That is, once I can get the engine and battery issue sorted out. I haven't had a chance to do any investigation into the battery yet.
I put the question to a Prius facebook group and it was suggested that I just charge each cell individually with a hobby charger before doing anything. Is it really that simple, or is there an advantage to using a charger like Prolong or Maxx Volts? I have the time, as the car will be sitting for a little while until I can get another engine to swap into it.

Carall, I will try to get measurements on the battery before doing any charging and report back.

Any other advice or comments are appreciated.

 

Finally got around to measuring voltages on the battery. I decided to pull all of the connectors and check each cell individually. The voltages ranged from 7.30-7.38. The lowest one was at the center and they rose steadily moving towards the outside.

Carall, based on your comments above, I assume this means this pack is still usable. Would you recommend purchasing a dedicated battery charger, or would it be reasonable to try charging these individually with a hobby charger, as mentioned in another group?

 

@Carall, @bisco,

I began charging the battery this weekend using a combination of advice from various threads on this site as well as a couple of how-to's on Youtube. I bought a CQ3 charger and some leads and am working my way through the pack using the following settings:

discharge current: 1.0
discharge shutoff voltage: 6.30
charge current: 3.0
capacity shutoff: 7500mAh
D>C, 3 cycles


So far, I've done two discharge/charge cycles on each battery before moving on. The first cycle gives fairly low capacity, since the batteries are already partially discharged. So far, I have had to manually restart a cycle since the battery capacity always reaches 7500mAh and ends the cycle. According to a guy on youtube, the battery is good if you can get your discharge mAh to get above 5000 mAh. All of the batteries ended up around 5700mAH on the second cycle.


1. Should I continue cycling each battery until I reach a certain discharge capacity? If so, what should my target be?

2. Should I set my next discharge limits lower than 6.3v, like is suggested by various people on this site? I think it might have been by @PriusCamper. If so, what should those levels be?

3. Will I be able to notably improve my battery life/capacity by doing additional discharge/charge cycles?


I appreciate your input and patience with a newbie.


Thanks in advance,

 

Can anyone suggest a good thread to read that might point me to the exact process? I have an idea based on various things I've read/seen, but feel like I might be missing something here. I've searched the site quite a bit using terms like "battery charging" or "battery reconditioning", but have come up empty.

Thanks