Adjust DC-DC output voltage && Two

Just to add to what's already been thrown out here, the Prius does an SOC "recalibration" (as it's been termed here) when it's internally estimated SOC varies drastically from the calculated SOC (that is to say, if the battery conditions change considerably during the drive it will "drift" to a newly calculated SOC to compensate for the additional / missing energy in order to prevent damage to the batteries). It's not necessarily tied to a specific voltage but generally happens at higher voltages because its easier to estimate SOC as the NiMH batteries start running up the "knee" of the voltage curve.

Introduction of an outside source of energy into the batteries (through a DC/DC converter in this case) will frequently trigger this drift procedure since there are small inaccuracies that slip in (noise, voltage differences, etc). It's not really a problem so long as the recalibration drift occurs before the batteries get damaged (an unlikely prospect given the other safeties in place I'll admit but meh, I've learned not to discount possibilities).

Andrew

 

Re: SOC Measurement

My understanding of the Enginer system is the opposite. The DC-DC converter is connected to the HV bus in-FRONT of the HV ECU sensor so that current flow INTO the OEM battery IS measured. Some other PHEV systems (contactor type) connect on the other side of the sensor and have to spoof the SOC to work correctly. Of course, current flow into the OEM battery is never measured 100% correctly...even for a non-PHEV Prius...thus the need for an occasional recalibrate.

 

with 6kwh of batteries you could probably run two converters in parallel.

 

I run mine at right around 3600W peak for a Gen II, given the constraints of the 14-15 amp current limit to prevent throwing a code.

 

So the max current output is selectable on the unit then?

 

What are you using to measure the 3600? Math formula or "instrument".

 

Current and voltage can be set, but you really have to know what you are doing. I wear high voltage gloves and use insulated tools to make adjustments.

Power = Current * Voltage. 15 amps out at 240V. BMS16C shows current and voltage (updates slowly, though), and I also use a Fluke 88V to measure voltage and AutoEnginuity to measure current at the HV ECU as a consistency checks.

It's not possible to say that you need a certain number of turns. You need to have the converter cover off and everything hooked up and running, so that you can adjust to the desired set points while the system is under load. Adjustments are not to be done without proper knowledge and equipment, this is why the procedure should only be undertaken by installers.

 

I'd be very careful about adjusting this.

Each converter is a bit different and the pots may have variable number of "turns" available to them. Sometimes you simply will run out of available turns. It is set at a specific setting from the factory for a reason.

If anyone accidentally lets the magic smoke out of their system by messing around with it, I hope that they are honest enough to admit their error when they go to order a new part.

If someone toasts their Enginer system because they pushed things a little to far, that should really be their expense to replace and not Jack's. Hopefully people agree with this logic. Jack's been pretty lenient about replacing defective parts, and I hate to see this generous policy abused just to satisfy someones curiosity of how far they can push things.

Seriously. Be careful. If you go to far, you'll know it, but by then it may be too late. And for goodness sake, 'fess up if it was your doing that blew up your system or wore other components out prematurely.