prius hv battery

how many miles on her? are you going to load test, replace bad cells and rebalance?

 

You can load test individual modules ( a module has 6 internal cells) using an automotive halogen headlight (use both filaments) and measure the voltage without load and after the load has been applied for 30 seconds. A weak module will exhibit a larger voltage drop than the others. Your other alternative is to put a load on the whole string of 28 modules using the newly designed load box that can be purchase with (or without) a Prius battery charger/maintainer that is available on the Prius Chat store and then look for weak modules.

JeffD

 

You don't think just using the high or low filament would provide enough load?

 

A higher load just works better. Our HV batteries can see loads of up to 130 amps (100 amps in older Gen2 Prii) in use.

JeffD

 

Is this even enough of a load to identify problematic modules? I see people use this light bulb as a load but as you said, while in the car, the loads are much higher

 

Both filaments in parallel will draw a load current that is a large fraction of 6.5 amps - the rating of our 7.2 volt modules (called a 1C load). This has successfully identified weak modules for several Prius owners dealing with HV battery problems.

JeffD

 

Good information, thanks professor

 

Any additional info on this new load box; looked around the store and only found the charger.

 

PM jeff652 to get current information on his products. His old discharger was just a simple unit with two light bulbs. He has a new automatic discharger which should be available shortly (I thought that it was already available for sale - see Prolong Battery Discharger testing | PriusChat ).

JeffD

 

I think your better off getting a mini vci and driving the Prius looking at real-time live data.

 

It's the box I had at the meet up.

But @jeff652 can handle the details.

 

What made you pull the HV battery out of the car? Was it the lights? What made you think the lights meant it was the HV Battery that was at fault?

The new box is a discharger, I don't think it can monitor the voltage drop on each module. Better way is to monitor the HV Battery with Techstream while driving the car observing and/or recording charge and discharge loads.

 

Yes, but it is an automatic "smart" discharger which means that it is unlikely to discharge the HV battery too far (as long as the battery is reasonably balanced). You are correct that to use it for a load test, you need to monitor the 28 module voltages during discharge and Techstream (MiniVCI for low cost) is a good option. Monitoring while the HV Charger/Conditioned is charging is not very useful as the charging current is relatively low to avoid overheating the battery.

JeffD

 

I wasn't meaning to use Techstream to monitor the charging/discharging using the Prolong charger/discharger. You wouldn't be able to do that as the car would be OFF. What I meant was to monitor the battery while driving observing current flows in realtime. I have edited my post to say that.