Charging hybrid battery

The smart thing to do is get the Prolong system, or something similar, and charge it SAFELY.
You'll need a fan blowing over it so it doesn't over heat.

 

What should you do? Bring lots of quarters because it’s going to be wack a mole time!

 

You can charge the whole thing at once, but you'll need the correct voltage and amperage charger. You can make one with a readily available power supply, but you'll have to do some research, and it'll cost over $100 these days.

Build Hybrid Battery Maintenance Gear For Under $100 | PriusChat

If you aren't doing a full balance charge you probably don't need to deal with the fan stuff.

I'd suggest watching the weber automotive youtube video on the 3rd gen prius hybrid battery pack.

Also consider a visual inspection of the current battery to make sure it isn't just an issue with corrosion on the buss bar.

 

You can do whatever you want. Use a regular car battery charger. That will work if you
put two together in series(batteries not chargers). But you can do that too id you want.
Don't worry about overheating, it's not important.
Rig it anyway you want.

 

Most likely the hv battery in your car is better than one that had been sitting unused for a long time.

Techstream won’t help much other than seeing voltages in your car’s hv battery.

Being a self starter is good but a lack of knowledge just makes repair attempts sure to fail. You are dealing with a 201vdc battery that normally will have bad modules needing replacement.

Maybe you can get a functioning battery by mix and match from both assemblies. Often bus bars, connectors and sensor harnesses are also bad and require careful cleaning or replacement in most cases.

There are a few good hv battery videos out there and a lot of bad ones.

Here is one about Toyota hv batteries:

 

Each one is 7 volts. Well, 7.2? Put two in SERIES, and that's 14.2.
A standard battery charger will charge at over 13 volts, close enough.
Balancing is very important.
If you ahve time to waste because your time is not valuable go ahead and spend weeks and weeks
playing with the battery.

 

Mobile mechanic? You get what you pay for and I am afraid mobile mechanics are not the solution here. Very few diy or mobile mechanics will have the equipment to do it the best possible way. Just like you, they don’t want to pay for the equipment.

In reality, there is a strong argument that reconditioning is a very short term solution in most cases simply because all the modules are old and worn. Just replacing the really bad few means others will be right behind. Maybe if you are willing to go back several times a year it’s all good.

Buying new oem for $2k or less means ten years or more with no hv battery issues.

 

Buy a new for a couple hundred more.

 

What's the voltage of the new used battery?

 

Perhaps you should read what other have said about green bean batteries.....
How much time do you want to waste waiting for them to come replace the defective battery,
again, and again, and again, and again................?

The SMARTEST way is to buy a NEW battery. Check ebay, you can find them.
There is even a JDM seller that has batteries.... Like the engines, that MIGHT be a good battery
for half the price.

 

Sounds like he doesn’t have basic battery wiring knowledge, you’re putting him up to a task that can literally blow him up, kaboom!