How 'smart' is enginer kit?

I can't answer all of your questions, since I'm just learning more about the Enginer system myself. However, here are a few things I know about the Prius:

The Prius battery can charge or discharge at about 20-21 kW sustained (100 amps at nominal 201.6 voltage). During maximum regenerative braking, you typically reach this level.

The useful range of the Prius battery (40-80% SOC) is 600 whr, so with 5 kW converter, you could recharge the entire battery pack in about 7-12 minutes, depending on efficiency. So you could recharge the battery pack down 1-2 bars to 80% peak SOC, in just a few minutes of idling.

I suppose if you wanted to "pre-charge" your HV battery, you could go into ready mode, turn on the enginer pack while idle, which would charge the HV battery pack at the rate of about 5 kW, minus losses. Then turn off the vehicle and the enginer pack. Then top off your enginer pack once again.

From Enginer's website:

5kW is about 20 amps at 240V, not 15 amps.

 

The current output of the Enginer system is adjustable. People with 2G have found that setting the output above 15 amps causes the car to code under certain conditions which requires a SGII or something to reset the car and get it going again. An 8kW system essentially is used to double capacity rather than double the current output.

When you stop for the night, I recommend using whatever power is in the pack to bring your HV SOC above 70%. Under different conditions, having an SOC above 70 will cause the ICE to fire and burn off the extra charge. There are relatively few days where I can push 80% on the HV without the ICE starting and taking down the charge.

The Enginer output can be shut off by dropping the ready signal. Also, it is configured to trim current down as the bus voltage approaches 240. This is not the ideal control scenario. It should control based on SOC of the HV but it doesn't. I'm ready to buy an Arduino controller to bring this functionality to my system.

 

Les, engineers aren't all that bad. They can usually fix a leaky faucet or solder a loose wire in a heartbeat.

I have a 4 kW unit. I've not done an installation on an 8 kW unit so I'm not exactly sure if they are delivered with one or two dc converters. That's a good question. My guess is one converter is delivered and that the cells are wired 4 kW x 2 to maintain the 50 volt output of the overall battery.

Regarding modulating the current. The current is supposed to be DC. But, by the time that switching power supply gets done with it, I'm not quite sure what the composition of the signal is any more. I really don't think it could be modulated one bit more.

Yes, the output voltage, output current and threshold voltage (used to trim current when threshold is approached) are all set by pots.

I'm not exactly sure what you are calling the slop factor, but if it's the variation in the SOC that the HV can accept, then that's probably entirely due to HV battery temperature. As you are probably aware, the Yoda HV is well sensored and I'm sure that the Toyota BMS uses the temperature value to adjust a number of operating parameters of the HV including maximum acceptable charge before ICE burn off.

 

I figured something like that. I was just making light of the fact that the output is so dirty, it makes a spark gap transmitter look like a precision oscillator.

Clearly the most elegant implementation would be to read the calculated HV SOC off the CAN-BUS, bias it against the charge limits and then feed a proportional control signal back to the DC Converter. After consultation with Enginer, they did not want to provide any specifics on the converter so simply recommended running the converter at full 14 amps output and killing the ready signal when SOC hit a threshold value and turning it back on when SOC dropped below that value.

As a side, on my 2G, I've noticed that the code occurs when running a fairly high SOC (>68%) and I'm coasting down off highway speed to take an exit and the Enginer kit is outputting >15 or so amps. I don't know if it's the current, the voltage (that may or many not be stable under different loads).