Traction battery rebuild question

Do not try to charge the Li-ion battery. You cannot recover those if they fail.
The ZVW30 battery is made up of 28 modules (smaller batteries). Good modules have a capacity of 6.5 amp hours. To charge them from full discharge you need to put in 9 amp hours of electricity because they are not 100% efficient. If you charge them at 2 amps for 4.5 hours you will have put in them 2 X 4.5 = 9 amp hours of electricity.

Do not try to charge them in parallel partly because cooling will be difficult with them all being charged together,and you would need to supply about 56 amps for 4.5 hours. It is not a good idea to charge NiMh batteries this way. The voltage would be between 8.5 to 9 volts current limited to 2 amps.

John (Britprius)

 

Discharge the module down to 6 volts, and set the charger to charge 6 NiMh cells at 2 amps it will set the voltage. Make sure the modules are clamped if they are not still in the battery.

John (Britprius)

 

your advises are very helpful

Thanks

 

A Supermate DC6 charger (or any of the equivalent available units) can be set to safely charge Lithium modules, PbA batteries as well as NiMh and NiCad but one at a time.

JeffD

 

Thanks Jeff. The OP has a 2014 Prius with Li-ion battery, and there is no way he should be trying to charge that.

John (Britprius)

 

I see in PC one person "ryousideways" Put 28 modules in parallel and charge. He said it took 6 hours for modules voltage to equalize.
What you think about it?

Thanks
Thusitha

 

Parallel charging is not a good idea as you don't get any information on the health of individual modules. If one module has a bad cell, it will scavenge a large percentage of the charging current and is likely to overheat and fail dramatically.

Again, the purpose of putting modules in parallel is to equalize them after rebalancing each of the modules individually.

JeffD

 

He was not charging the modules he was equalizing the voltage on them so that they were all the same. You do this by connecting them all in parallel and then leave them to equalize the voltages.

John (Britprius)

 

I got the point
Thanks Jeff

 

Oh Now I understand.

This is for Example:
I have a battery pack....it has 28 modules
Discharge and Charge 3 times note down all 28 cells charge and discharge data.(set the charger to 0.7Ahr and 6Vfor Discharge and put charge rate to 2Ahr for Charge))
one module was bad.
Replace the module and assemble the battery pack
Discharge and charge 3 time only replaced module
at last connecting all modules are parallel and equalize the voltage-(Is there a any function for equalize the voltage in the charger? What is Ahr and voltage?)

Thanks
Thusitha

 

No there is no function in the charger to equalize the voltages in the charger. Just connect them in parallel and leave for a few hours. Otherwise I think you have the the correct way of doing this.

John (Britprius)

 

At last step I should not use the charger.
Thanks
Thusitha

 

Do not use the charger at the last step.

John (Britprius)

 

Dear John,
you are very helpfully person is in this form and PC. I got lean many things for you.And you spend your valuable time for me. If I need more information I will be contact you.

Thank you so-much
Thusitha

 

What is discharge(mAhr) and charger(mAhr) result range?

Thanks
Thusitha

 

The figures that matter for battery condition is the discharge figure. A good or new module will give a reading of around 6500 mah (6.5 ah) when discharged. To achieve this output because of the inefficiency of the charge cycle of the modules we need to charge them with around 9000 mah (9 ah). We get less out than we put in.

John (Britprius)

 

Dear John,
I think I ask my question this way......
After 3 times discharge and charge I have to note down all results. If u see result sheet u can say which model is bad and which model is good.those result will show the Charger. my question is what is charging mAhr range and Discharge mAhr range.

Thanks,
Thusitha

 

Anything above 4000 mah discharge capacity will still give good results when used in the Prius although the higher the better. The charge input should remain at what you set on the charger for input (9000 mah). How much of this is captured by the module is what we are interested in. This is the module capacity.
Because the modules are connected in series in use the output of the complete battery in mah can only be that of the weakest module.

John (Britprius)

 

Hi John,
One PC member is says(ryousideways | PriusChat) he used bellow settings for Charge and Discharge.

Settings:
Charge at 5 amps up to 7250mAhr
Discharge at .7 aMhr down to 6 volts
DSCH<CHG for 3 cycles.
Other settings: I set the timer limit to 720 minute cut off. I also set the cool down period to 5 minutes.

why he Charge at 5 amps up to 7250mAhr.

You told me charge it 2000mAhr. I am bit confused. Can you please bit explane.

other one is if I measured modules voltage some of them are 7.7v. Why it show 7.7v ? The moduel voltage is 7.2v. what is the reason for it?
Thanks
Thusitha

 

Dear John can you please bit explane about question if you have free time..

Thanks
Thusitha