2010 Prius II HV Battery Reconditioning

First time starting a thread so here goes :

In February of 2017 with our 2010 Prius II at 149 k miles, I had @jeff652 install the discharge ready harness from Hybrid Automotive. I have purchased both the Charger and Intelligent Discharger for use. I bought this setup as the battery was going to be out of warranty and wanted to maintain it as long as I could. I am not an electrician or EE, so I thought this was the easiest and safest way for me to make our Prius last as long as possible.

In March of 2017, I did a top end balancing using the Charger and it took a little shy of 20 hours to ensure the voltage was stable at 240v for 4-6 hours. Since that Top End balancing, the HV battery has lasted longer in stop and go traffic and am averaging 52 mpg.

Over the Memorial Day holiday weekend, decided to take on the Reconditioning process. I did 2 full cycle discharges (down to 134v and 84v): started the full charge Friday night and was done with the last charge cycle Monday morning.

Here's a pic of the mileage so far:


This was with a strong 30-45 mph delta cross breeze, so not too bad.

Next reconditioning should be Thanksgiving and will do the 2 cycles.

Thanks again for the help and equipment to make this process super easy @jeff652 .

 

Just finished up a top end balancing .

Decided to only do a top end balance as the battery is still performing well (no quick cycling of the charge indicating bars, battery lasting in traffic, etc).

Started yesterday at noon:



It was at 239 volts at 9 pm when I went to bed. This morning:



Should be good until Memorial Day when a 2 cycle reconditioning occurs.

 

Don’t forget that you are reconditioning while the HV ECU and Prius is off. It is also the max that the HV ECU recognizes (it never truly gets to 100%.

Just wait about an hour after the charger is disconnected prior to starting the Prius up .

 

What is your plan:

• How long have you been charging?
• 2 cycle discharge ?
• What is your desired endpoint for the last Discharge cycle?
• Any signs on the battery of wear and tear? Or is this preventative maintenance?

I would start the 134 v discharge cycle now.

Then come back in 4-6 hours to begin the charge cycle.

 

I took the plunge and satisfied with our investment .

The best is if you can find someone in your area that you can share with to reduce costs.

 

So:

• 2 discharge cycles?
• 134 v then 84 v?
• Or 2 cycles at 134 v?

The battery behavior sounds similar to what I witnessed in our 2010 with 168 k miles. I did a 2 cycle discharge process: first tip 134 volts then to 84 volts and called it good.

It is normal for the bars to drop quickly from 4-2 as it is designed to spend most of its time in the 5-6 bar range.

I would start the Intelligent Discharger and keep us posted .

 

If you are doing 3 full cycles, prepare for a 4 day commitment .

If you do a 2 Discharge cycle, you’ll be at about 3 days.

The 17 v discharge is very low. I’m not sure what benefits it achieves as 134 and 84 volts are outside what the HV ECU wants.

Keep us posted .

 

When Jeff installed the harness on our Prius, we had a nice 2 hour long chat.

During our conversation, I gleaned that our HV battery was in good shape and probably only needed the top end balancing (wouldn’t need to discharge cycles). I chose to do it after doing a top end balancing to see what effects it would have.

If the battery is performing well (other than the perceived quick bar cycling), 2 Discharge cycles is more than appropriate.

After the Discharger is done and you begin charging, don’t be surprised when the amps jump around. This is normal until 203 volts. Also if you don’t catch the Discharger when it hits the target, the voltage will rise and depending on the time between the Discharger turning off and when you get out there, it could be a lot.

Good luck and keep us posted .

 

Do you have the bulb Discharger or Intelligent Discharger?