Gen II hybrid battery replaced

Seanant24 · Jun 19, 2014

The hybrid battery in my 2007 Prius had two bad cells after replacing the bad cells with a new cells and balancing the battery as a whole and replacing the battery back into the car the car ran for approximately 20 miles and then all of our error lights came back on and the hybrid battery was no longer giving power. The following is a list of all of the Error codes that we are dealing with.

Hv system regeneration malfunction
Malf engine control unit
Malf in HV system
Batt block 13 weak

Has anyone had similar problems or have any advice please help we're desperate to get this car back on the road.

JC91006 · Jun 19, 2014

What block did you replace? 13?

SM-N900P ?

Seanant24 · Jun 19, 2014

We replaced cells 3 & 16 the voltage read the same 7.89 for all cells after replacing & balancing the pack. We also replaced the 12 volt battery & removed & cleaned out the fan

Seanant24 · Jun 19, 2014

after reconnecting the 12 V battery, all of the warning lights go out. Then after driving normally for about four miles, the hv fan goes on, about a mile later I hear a solenoid click and the car gets sluggish with no power from the traction battery. If I pull over turn off the car turn it back on the warning lights still on and car drive normally for one-mile with fan running.

ericbecky · Jun 19, 2014

Do you have a way to scan the car while it is running? That way you can see the battery module info under real conditions.

Is there a reason you are not replacing both modules in block 13?

Also did you thoroughly check the condition of the bussbars and sensing wires?
If there is corrosion it can lead to breaks in these components.
These breaks may cause erroneous readings which then lead to error codes.
Either remove, clean, and resolder the broken components, or buy a new set of bussbars for $275.

Feel free to call me if you need help.

MTL_hihy · Jun 19, 2014

Seanant24 said: ↑

after reconnecting the 12 V battery, all of the warning lights go out. Then after driving normally for about four miles, the hv fan goes on, about a mile later I hear a solenoid click and the car gets sluggish with no power from the traction battery. If I pull over turn off the car turn it back on the warning lights still on and car drive normally for one-mile with fan running.
Click to expand...

You don't just check the voltage on the modules when you pull it apart and use that to decide if the modules are good or bad (they should be cycled for capacity if you wanted to do it properly). Even if you skipped that step you absolutely must load test your modules to make sure they were all good.......this is the most important step IMHO. Load test them all (including the ones you pulled out as "bad") and post up your voltage drops and I'll bet you'll find another bad one in there still (possibly even the replacement modules).

Here's how to do the testing:

Gen II Prius Individual Battery Module Replacement | Page 13 | PriusChat

Seanant24 · Jun 20, 2014

MTL_hihy said: ↑

Seanant24 said: ↑

after reconnecting the 12 V battery, all of the warning lights go out. Then after driving normally for about four miles, the hv fan goes on, about a mile later I hear a solenoid click and the car gets sluggish with no power from the traction battery. If I pull over turn off the car turn it back on the warning lights still on and car drive normally for one-mile with fan running.
Click to expand...

You don't just check the voltage on the modules when you pull it apart and use that to decide if the modules are good or bad (they should be cycled for capacity if you wanted to do it properly). Even if you skipped that step you absolutely must load test your modules to make sure they were all good.......this is the most important step IMHO. Load test them all (including the ones you pulled out as "bad") and post up your voltage drops and I'll bet you'll find another bad one in there still

MTL_hihy said: ↑

Seanant24 said: ↑

after reconnecting the 12 V battery, all of the warning lights go out. Then after driving normally for about four miles, the hv fan goes on, about a mile later I hear a solenoid click and the car gets sluggish with no power from the traction battery. If I pull over turn off the car turn it back on the warning lights still on and car drive normally for one-mile with fan running.
Click to expand...

You don't just check the voltage on the modules when you pull it apart and use that to decide if the modules are good or bad (they should be cycled for capacity if you wanted to do it properly). Even if you skipped that step you absolutely must load test your modules to make sure they were all good.......this is the most important step IMHO. Load test them all (including the ones you pulled out as "bad") and post up your voltage drops and I'll bet you'll find another bad one in there still (possibly even the replacement modules).

Here's how to do the testing:

Gen II Prius Individual Battery Module Replacement | Page 13 | PriusChat
Click to expand...

(possibly even the replacement modules).

Here's how to do the testing:

Gen II Prius Individual Battery Module Replacement | Page 13 | PriusChat
Click to expand...

Thank you for the advice about the load test. It seems like all the cells

Seanant24 · Jun 20, 2014

MTL_hihy said: ↑

Seanant24 said: ↑

after reconnecting the 12 V battery, all of the warning lights go out. Then after driving normally for about four miles, the hv fan goes on, about a mile later I hear a solenoid click and the car gets sluggish with no power from the traction battery. If I pull over turn off the car turn it back on the warning lights still on and car drive normally for one-mile with fan running.
Click to expand...

You don't just check the voltage on the modules when you pull it apart and use that to decide if the modules are good or bad (they should be cycled for capacity if you wanted to do it properly). Even if you skipped that step you absolutely must load test your modules to make sure they were all good.......this is the most important step IMHO. Load test them all (including the ones you pulled out as "bad") and post up your voltage drops and I'll bet you'll find another bad one in there still (possibly even the replacement modules).

Here's how to do the testing:

Gen II Prius Individual Battery Module Replacement | Page 13 | PriusChat
Click to expand...

Thank you for the advice. We did a load test and it appears all the cells are good. Below are the results. We also cleaned the connector for the busbar. Any other advice before we reinstall the battery in the car? Are we missing something?

7.84 7.78. -.06
7.87. 7.80. -.07
7.90. 7.83. -.07
7.86. 7.78. -.08
7.86. 7.78. -.08
7.86. 7.78. -.08
7.87. 7.79. -.08
7.85. 7.78. -.07
7.85. 7.77. -.08
7.86. 7.77. -.09
7.85. 7.78. -.07
7.85. 7.77. -.08
7.85. 7.77 -.08
7.85. 7.76. -.09
7.85. 7.77. -.08
7.85. 7.78. -.07
7.85. 7.77. -.08
7.85. 7.76. -.09
7.85. 7.77. -.08
7.85. 7.77. -.08
7.84. 7.77. -.07
7.85. 7.77. -.08
7.85. 7.76. -.09
7.85. 7.77. -.08
7.85. 7.77. -.08
7.85. 7.77. -.08
7.84. 7.7. -.07
7.87. 7.8. -.07

Replaced bad cells
6.34. 6.10. -.24
6.33. 6.06 -.27

ericbecky · Jun 20, 2014

Can you please regularly report back on this thread? Would be good to know how many more times you have to come back and readdress any pack issues. Or hear any more lessons learned.
Too often it doesn't work out and people don't come back and explain why. Perhaps we could have helped them more.

Seanant24 · Jun 20, 2014

MTL_hihy said: ↑

Seanant24 said: ↑

after reconnecting the 12 V battery, all of the warning lights go out. Then after driving normally for about four miles, the hv fan goes on, about a mile later I hear a solenoid click and the car gets sluggish with no power from the traction battery. If I pull over turn off the car turn it back on the warning lights still on and car drive normally for one-mile with fan running.
Click to expand...

You don't just check the voltage on the modules when you pull it apart and use that to decide if the modules are good or bad (they should be cycled for capacity if you wanted to do it properly). Even if you skipped that step you absolutely must load test your modules to make sure they were all good.......this is the most important step IMHO. Load test them all (including the ones you pulled out as "bad") and post up your voltage drops and I'll bet you'll find another bad one in there still (possibly even the replacement modules).

Here's how to do the testing:

Gen II Prius Individual Battery Module Replacement | Page 13 | PriusChat
Click to expand...

Thank you for the advice. We did a load test and it appears all the cells are good. Below are the results. We also cleaned the connector for the busbar. Any other advice before we reinstall the battery in the car? Are we missing something?

7.84 7.78. -.06
7.87. 7.80. -.07
7.90. 7.83. -.07
7.86. 7.78. -.08
7.86. 7.78. -.08
7.86. 7.78. -.08
7.87. 7.79. -.08
7.85. 7.78. -.07
7.85. 7.77. -.08
7.86. 7.77. -.09
7.85. 7.78. -.07
7.85. 7.77. -.08
7.85. 7.77 -.08
7.85. 7.76. -.09
7.85. 7.77. -.08
7.85. 7.78. -.07
7.85. 7.77. -.08
7.85. 7.76. -.09
7.85. 7.77. -.08
7.85. 7.77. -.08
7.84. 7.77. -.07
7.85. 7.77. -.08
7.85. 7.76. -.09
7.85. 7.77. -.08
7.85. 7.77. -.08
7.85. 7.77. -.08
7.84. 7.7. -.07
7.87. 7.8. -.07

Replaced bad cells
6.34. 6.10. -.24
6.33. 6.06 -.27

ericbecky said: ↑

Can you please regularly report back on this thread? Would be good to know how many more times you have to come back and readdress any pack issues. Or hear any more lessons learned.
Too often it doesn't work out and people don't come back and explain why. Perhaps we could have helped them more.
Click to expand...

Hi Eric,
As you can see we have replaced the 2 bad cells in the pack, balanced the pack, done a load test & cleaned the busbar. We have not reinstalled the pack back into the car yet. Are we missing any other steps? Please advise.

MTL_hihy · Jun 20, 2014

Seanant24 said: ↑

Hi Eric,
As you can see we have replaced the 2 bad cells in the pack, balanced the pack, done a load test & cleaned the busbar. We have not reinstalled the pack back into the car yet. Are we missing any other steps? Please advise.
Click to expand...

After load testing them all you should be balancing the modules for 24 hours before installing again.

Seanant24 · Jun 21, 2014

I want to thank everyone for the advise, everything was useful information. It seems after cleaning the connectors on the busbar the car is running properly!! It made through a 40 mile test drive & today we're planning about a 200 mile trip.

daniellesprius · Jul 1, 2014

Hi I have a 2005 Prius & my Hybrid Battery Pack is bad :.( obviously the car is not worth putting $4000 into it so I'm looking into buying a refurbished one.
Does anyone know of a reputable place in Kentucky or Tennessee?
Thanks!!

ericbecky · Jul 2, 2014

Can you install the battery yourself or do you have an independent mechanic? I can send one to you directly.

Gen II hybrid battery replaced

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