Regen KW Curve

[magudaman]

I created these two charts below while doing a quick stop to get an idea how much power the car allows back in the battery at different speeds. Looks like it pegs out around 52Kw regen ~70hp. Wind was still this day with ambient around 49F. My pack was around 60% remaining.

Overview:

Detail:

 

[brogult]

Cool! And interesting that it allows a 2C+ regen charge. How did you obtain the numbers?

 

[davideos]

It seems that if I put the car in 'L' when breaking a bit harder than usual, I can get more regen than if I did not. I'm curious if you tested the car's regen ability while in 'L' as well. I would expect the amount of regen to be the same regardless if in 'L' or 'D', but nonetheless, I'm a bit curious.

 

[hybridbear]

For a point of reference regarding charging & L:
The Energi vehicles have a 7.6 kWh pack and allow 35 kW as the max charge rate & 67 kW as the max discharge rate. Shifting to L gets you about 22-25 kW of regen in the Energi.

A 35 kW charge rate to a 7.6 kWh pack is much faster than what the Focus does according to this chart.

magudaman: how did you capture the data?

 

[magudaman]

So I got the data using Forscan (http://www.forscan.org). It is a ODB (On Board Diagnostic) reader program that is setup specifically for Ford Vehicles. Some one spent a lot of time building that awesome program and figuring out what all the data actually meant. Download the program, pick up a 12 dollar ODB2 Reader off amazon, and start pulling all kinds of amazing stats. There must be over 150 data point you can look at on our car all with something like 5ms refresh rates too.

At the time I was recording
- Bat Pack Voll (Full pack voltage)
- Batcurbecm (Full Battery current)
- avertemp (average battery temp?)
- Bat_cool_inlettemp (battery outlet coolant temp)
- Bat_in_Cooltemp (battery inlet coolant temp)
- Bat_to_empty_estim (watt hours remaining)
- Discharge limit (max KW allowed to be pulled from battery
- Hev_bat_var_v (highest offset voltage between cells)
- H_Batt_temp (additional battery temp monitor)
- Max_ECU_temp (ECU temp max)

This is the ODB2 USB device I purchased: http://www.amazon.com/gp/product/B004O5HXYS/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

 

[WattsUp]

At the time I was recording
- Bat Pack Voll (Full pack voltage)
- Batcurbecm (Full Battery current)
- avertemp (average battery temp?)
- Bat_cool_inlettemp (battery outlet coolant temp)
- Bat_in_Cooltemp (battery inlet coolant temp)
- Bat_to_empty_estim (watt hours remaining)
- Discharge limit (max KW allowed to be pulled from battery
- Hev_bat_var_v (highest offset voltage between cells)
- H_Batt_temp (additional battery temp monitor)
- Max_ECU_temp (ECU temp max)

Sorry if I'm not following, but how to get a measure of "Regen KW" from these?

 

[magudaman]

I forgot to mention I also have the vehicle speed displayed in km/h

The regen is negative kw, negative because it's flowing into the pack no out.

I am recording amps and volts of the battery pack:

amps * Volts = Watts ; watts / 1000 = Kilowatts (kw)

 

[WattsUp]

The regen is negative kw, negative because it's flowing into the pack no out.

I am recording amps and volts of the battery pack:

amps * Volts = Watts ; watts / 1000 = Kilowatts (kw)

Still not quite following. Which parameters give the "volts" and "amps" measurements that you're referring to?

Is it the "Bat Pack Voll (Full pack voltage)" and "Batcurbecm (Full Battery current)" parameters, respectively?

If so, apologies. It isn't clear from their names, which seem to imply static values that apply to a fully charged battery pack (as opposed to instantaneous measurements).

Or, is the term "full" in the parameter name meant to denote "total" (as in, the total voltage of both battery packs together)?

 

[hybridbear]

I have used FORScan with the Fusion but haven't ever gotten it working with the Focus. How do you record data from FORscan? I wasn't aware that it had logging capability.

 

[magudaman]

Still not quite following. Which parameters give the "volts" and "amps" measurements that you're referring to?

Is it the "Bat Pack Voll (Full pack voltage)" and "Batcurbecm (Full Battery current)" parameters, respectively?

If so, apologies. It isn't clear from their names, which seem to imply static values that apply to a fully charged battery pack (as opposed to instantaneous measurements).

Or, is the term "full" in the parameter name meant to denote "total" (as in, the total voltage of both battery packs together)?

The descriptions in parenthesis are quick descriptions I made of the parameters from the software which is at the left hand side. They are not static values. Full pack voltage refers to the complete pack as opposed to upper pack or lower pack. Full current was referring to the same "full" as the voltage.

Bat Pack Voll (Full pack voltage) = Volts
Batcurbecm (Full Battery current) = Current

 

[GladeStorm]

On the ForScan monitoring tab there is a Save-log-data button. It will save whatever you had last monitored (start to stop). Most of the data is recorded at about 20ms, but I have recorded over an hours of data without problem. I save as CSV file and then dump into a spreadsheet for analysis.

 

[fbitz777]

I hope that some of that any excess Regen electricity goes to the heater directly (100% efficient) for us in cold climates with reduced range.