Battery Module/Block Identification

A block is two modules. The car has 28 modules and 14 blocks. The way the modules are lined up in series means every other cell is the start of a new block (and where the battery control module sensing circuit is hooked up). #1 is closest to the battery module, 14 the farthest. All of the modules are in series. Count every other module until you reach the failed unit you saw on the data list.

A load test will bring out the failed cell for sure. Sometimes even the DLC snapshop data for a P0A8o won't show enough variance to condemn the cells unless you load it down and watch the voltages manually.

I commend you for rebuilding your pack, and attempting it again. Have you considered the long term savings of getting all-new factory new cells and self-installing instead of doing this every so often? I'm a fan of the longterm repair, although I really respect the DIY type. I'm of the opinion that module replacement is a great short term fix but I don't recommend it as a long term solution.

 

This is something of a follow up question to the above.

I'm using EngineLink on my phone, and am just becoming familiar with it. I had assumed that the voltage coming off of a block would be in the 14v range, but am getting logs that return an average of around 44v.

What am I not understanding?

Thanks much,

Ray~

 

This is the first Prius specific use of that particular software I have seen, so perhaps it is a new one for the community to know about. There are plenty of cases of various Brand X readers giving false data, so I might question the software maker about it. You should see the ~14V range that Techstream reports for block (module pair) voltage.

 

Using the ieGeek WIFI Wireless OBD2 module, and after much fiddling, retrying, etc., I have sent an email to K Solutions, with a log file, so will wait to see, and report back.

Thanks much

Ray~

 

I am using Engine Link on my Gen III and have the correct voltage for battery modules. I have seen several Gen II users with no problem.

K Solutions is very responsive so should be able to tell quickly with the log file.

 

Load testing should show you which modules are not performing up to par but block 14 should be the module pair on the far end of the pack furthest from the ECU (see pic).

 

I know this is an old post, but when I linked it in another thread as to how to know which block is which, at least two people said that it is the opposite. They said that block 14 is closest to the ECU. See post #37 & #40 here. Red Triangle of Death | Page 2 | PriusChat

 

If you have any question on which is the bad module you can just check the voltage and run a load test to identify which aren't performing properly.

 

Seems strange, that something so crucial should be so poorly identified.

 

The problem it is not consistent across generations of Prius–in some it is one way and in others it is the other way. As I have a Gen II, I just remember which way it is for a Gen II. I couldn't tell you what is is for other generations, I just know it is not all the same.

 

Yeah couldn't they have some sort of strap that runs over top, with clear labels. It puts me in mind of a Honda valve clearance instruction, with a totally messed up diagram indicating which end was cylinder #1 vs #4.

 

On the 1st gen, block 1 is next to the ecu (driver side). However, in the 2nd gen block 1 is away from the ecu (passenger side). Again, just measure voltage at rest and under a load and you'll see which ones are weak or faulty.

 

just want to make everything super clear at a glance

 

What gen?

 

Thanks, @johnjohnchu. That is super clear. I know this is a Gen 2 forum, but it would be nice to specify that so people can be sure it's the right one for their car.

 

Another quick identifier....gen 1 has 38 modules and rubber vent tubes, gen 2 has 28 modules and the rubber vent tubes...gen 3 does not have the vent tubes(at least on the batteries I've disassembled)

 

My 2010, gen 3 has the vent tubes, think they stopped a couple years later

 

Vent tubes were being removed sometime in 2011 and all gone by 2012.

Battery blocks are counted from the module which you attach the negative lead, voltage grows with each block. Voltage at block 1 will be ~16 volts, voltage at block 14 will be ~224 volts.

Gen 2 and gen 3 are the opposite. Gen 2 uses a long negative lead and a short positive lead, gen 3 uses a short negative lead and a long positive lead.

If you're working on a Camry or Lexus battery and are confused which block is which just follow the negative lead to block 1.

 

this should be "stickier" to the top