Gen II Prius Individual Battery Module Replacement

I have a question at this point. I have codes 526 and 612 which requires looking into parts closely connected to hv battery. Therefore, to find out what is the exact problem I have to disconnect the hv battery. Afterwards, do I have to do balancing since the battery was disconnected as a whole from the system. In what context the balancing is required to do?

 

The traction battery is disconnected from the system via a relay every time you turn off the car. If you work on it and pull the orange safety disconnect, you're simply disconnecting it at a second point a little closer to the battery pack so you don't get shocked at the exposed terminals.

 

So, I guess after I figure out the problem if it is not from the hybrid battery then I reconnect it after repair should be fine. Right? I was thinking about whether equalizing of voltages across the modules are needed in this case.

 

If your traction battery is original, it would be a good idea to balance it periodically with a Prolong grid charger from Prolong Battery Systems. Extending the life of your hybrid. – Hybrid Automotive . They do help prolong its service life. And, if you're replacing modules, it's pretty much required if you want your repair to last very long.

But for your specific question, there is nothing needed other than to make sure you properly re-install the safety disconnect. Many people forget the last step. Insert the plug, fold the handle flat, and THEN slide the handle toward the hinge. If you miss that last step, the car will not go to ready mode.

I haven't looked up the codes you mentioned, but I seem to remember that the 612 is a leak to ground somewhere in the battery. That means you probably will be doing some replacement work in there. Or else getting a new battery, which is my recommendation if you want something reliable. Then again, it might just need a good cleaning.

 

That is a good idea. But it also looks very expensive. Not that what I might need for now.

 

There is not usually an inexpensive reliable repair for a Prius HV battery issue. Some inexpensive repairs last a month or less before stranding the driver somewhere inconvenient.

If the issue is the battery and you are DIY, the best inexpensive solution is @2k1Toaster 's kit of new cells. I linked to his site in my signature but I do not know if he has any unsold kits in his October shipment. That kit gives you basically a new battery for $1600 shipped and you can sometimes resell some of your old modules to recoup some of the cost.

 

+1! You will get what you pay for unless it's a rebuilt battery. In that case, you'll pay a lot more in the long run.

Also, you can replace all the modules as a set using modules from a battery out of a totaled newer Gen 3 (or even a Gen 4 if it's the right battery and you can get your hands on one. My wife's '07 has all the cells out of a 2015. They all match, so you're not playing whack-a-mole that way.

 

You could build your own charger from inexpensive premade led power supplies, or simply put a few generic power supplies in series with some wire nuts. Add them together until you have enough voltage. Or repurpose an old electropheresis Powers supply of the correct voltage. Plenty of those around or online.

 

Having some issues charging cells with the Prophet Sport Quad chargers.

Discharging at 1-1.5A down to 6.0V. Capacity cutoff set at 7300mAh.

Charge rates anywhere from 1-3.5A. Cycling 5 times. Capacity starts at around 1800mAh, goes up to 3500-4500mah by the 2/3 cycle, and back down around 2000mAh by cycle 5. Any ideas?

 

Sounds like either your charge profile isn't taking the temp curve midway into account. Or your discharge measurement is wildly noisy.

 

How can I fix this? I have 3 of the chargers sitting near each other, and the wires are close to each other.

 

Without knowing the charger no idea. Poor equipment leads poor results.

You need to figure out if (1) you are not charging them enough and the discharge reading are accurate, (2) you are charging them fully and the discharge readings are wrong, (3) both 1 and 2 in some combination.

I'd do a full charge on a battery. Measure the voltage. Let it sit overnight. Measure the voltage. Charge it again. Measure the voltage. The two final voltages should be the same and the overnight rest voltage should be very close. If there is variation, something's messed up with the charge cycle.

Then if you have an option to do a constant current discharge, set it stupidly low like 100mA and check it over the course of a couple days. Easy numbers over a long time get rid of some of the noise if the equipment is just crap to begin with.

 

Using these:

 

Hi. I got some cq3 chargers from Amazon. I noticed you got same thing too.
How do you put up with the setup:
Here's my setup on the charger:
1. Cut off capacity 7000mAh
2. Charge current 1.2A
3. Discharge current to voltage cutoff 5A/6.0V
4. Battery setting NiMH chemistry
Is this settings, correct pls?
My modules tends to just get to 1360-2000mAh, then stops.
Is there any problem with my settings?

Thanks

 

Not me. I use the Keithley's. I suggested you to do the same when you were shopping around. Again, poor equipment yields poor results. :/

 

Wao! Well, I did buy some venom quad pro chargers also.
Mehn, I mistake buying that stuff then.

 

What chargers are suggested then?

 

I use pro equipment so not really one to recommend other solutions. But keep in mind that these are usually meant to charge RC vehicle batteries. If your charger only gives you 18minutes of runtime versus 22 minutes, nobody cares. These aren't the most well built things on the planet in the first place and then we are using them with gigantic batteries they weren't designed for and where the accuracy required is low.

Usually once you figure out the chargers weird quirks it will work fine. It just needs to be calibrated. I still suggest doing a charge multiple times to get to full charge and then a nice slow discharge. It doesn't really matter how it is charged as long as you get past the voltage hump where it droops but is actually charging more. If you keep charging it, it will just get really really really hot. But that's why you're there to babysit it!

But my battery equipment of choice is the 2281S-20-6. Can do 20V and/or 6A max. The price is in the $3k USD range. But 6 digits of precision.

 

A helpful post. Here I have two questions:
1. So balancing is done for each individual module. How do you make sure, that they will all have same volts when you put them together?
2. How to monitor capacity or measure capacity?

 

The advantage of a grid charger such as that in the Prolong reconditioning system is that is charges quicker and seeks to intelligently balance the modules in the pack.