Hybrid Battery Reconditioning/Replacement Options?

Get the Prolong system. It has the PROPER charger and discharger and is the safest way to do it.
You may be able to revive it. If you can't, there is no sense in playig wack a mole with trying to swope
out blocks... Unless you have days and days to play with them.
But if you want it "fixed", try the Prolong system, or replace it with the Sodium Pack...

 

it's a big expense to gamble on vs putting the money into a new battery.
what year and how many miles?

 

The grid charger charges with a low current for a long time. It takes advantage of the charging characteristics of nickel-metal hydride batteries to overcharge with a low current, which can help your battery restore balance. However, if the capacity of the cells itself is lost too much, this kind of charging cannot solve the problem. The problem is, you can find a cell with a capacity lower than 2ah and replace it. I don’t know the threshold value for Prius to detect battery capacity. I can only tell you that battery cells higher than 2ah seem to work very well in the car. The larger the capacity, the better. good.

 

I have never owned a power grid charger, and I don’t know if it can automatically discharge. I only have a regulated power supply and a homemade discharger, and it needs to be done manually, which is very time-consuming. If you don't like this, you can also buy a charger for model aircraft, which can charge and discharge. The end of charging and discharging is automatically detected, and you can also get capacity information.

 

check hybrid automotives website. should have all the info you need

 

When the hv battery is in the car, you can turn it on and it will slowly discharge. Turning on the air conditioner will accelerate the discharge, or slow EV driving will consume power. Due to Toyota's charging and discharging strategy, it cannot drain the battery. If your hv When a battery has damaged cells and you must open it, you have the opportunity to drain it through a slow discharge, which may help alleviate the memory effect of NiMH batteries.

 

You'll find out more about the pack once you get it open and start taking voltage readings. 7.4 volts is a modules nominal rating and they charge a few volts higher somewhere around 8.5 to 9 volts.

There are 6 ( 1,2 volt (nominal)) cells per module and 28 modules in the Gen 2 and 3 Prius hybrid battery pack.

You have to be careful when choosing a charger to make sure it will charge NiMH batteries, since many newer chargers will only charge lithium. The charger must also be rated for at least 6 NiMH cell packs, but most that come with NiNH settings already support more than 6 NiHN cell packs, still it's in your best interest to make sure.

Since reading above it looks to me like you might have an interest in working on modules individually.
Here is a link to a charger / discharger that is used fairly widely by priuschat members and has some decent youtubes on how to use it too.

EV-Peak CQ3 100W x4 AC/DC Quad Balance Charger

With this charger you can cycle 4 modules at a time. Some even have several of these chargers.

 

That's called self discharge.
Measuring it is one of the ways to predict how well a pack will work after it's been cycled and balanced and reinstalled in the car.

 

There are many theories about how best to run a cycle on a set of 6 cells in a prius NiMH module.
If slow charging a module at below an Amp, - timed charging - is one recommendation. If charging that way, you want to get a reading of the charges ending voltage and / or the voltage when it stops increasing during the charging session. Many say that 350 mA is fairly safe to let a 7.4 volt nominal NiMH module charge for 24 hours, as long as the module temps are monitored and or fan cooling is used effectively.

Resting time is not nearly as important as some of the other settings, it lets the cells in the module drop their voltage from the the high point to where the voltage starts to settle into the modules normal rate of self discharge. Self discharge is another strong indicator of how healthy a module is. Monitoring a module for 24 hours, every hour or so, after a charge session, will give a general idea about the modules rate of self discharge. A long time monitoring, every day after the first 24 hours, or however long it takes to cycle all the modules in the pack, will give a much stronger idea of how the pack will behave when it's in the car.

If you have a charger/discharger that can connect to a computer and also has a decent app to monitor charge/discharge cycles, you can see those and sometime a few other important variables graphed visually, but it's not somethings that is always obvious the first couple or even the first hundred times looking at the graphs. Learning the ins and pitfalls of cycling modules is a process, until the modules stop responding to the cycling, which will happen eventually. Temps below freezing are no walk in the park for hybrid batteries either.

Temp:
most definitely don't want to charge near freezing or above 100 F. ( 60 F ) is pretty close to optimal for NiNH chemistry cells from my experience. I've seen modules take a few more watts during charging at 50 F but it falls off rather fast when temps drop below that, ( Reducing the charge voltage ) and letting charge cycle run for a longer time at ( lower voltage ) is one way around the low temp barrier, but you want to proceed with caution when you do that, especially with older, less healthy - cells modules packs - which ever way you are charging / discharging them. This is also true of higher temps above 100 F, but because so many have early degradation rates with local high temps, many have named High Temps as the No 1 killer of hybrid packs.

 

Nice set of posts ! Caution using your chargers on ebike and scooter packs that you have not already modified into smaller sub packs. The lithium (cells in series) pack size is limited to 6 cells in series and most ebike and scooter packs are way more than that.