Introducing the Engine Stage Assistant

The new release of Hybrid Assistant, for selected car models (Yaris, Auris, Prius3), will advise you about the engine stages. 
At car power-on, a "Play" icon will appear on the engine icon if the engine needs to be warmed up and will start in a few moments. 
You can prevent it by switching to N or selecting EV mode. 

When the right conditions for an idle check are met, a "Pause" icon will show up. 
If you begin to coast, the engine will perform the idle check and will switch to stage S4.


"HA Tips" - a video serie for HA users

With the help of an appassionate user, Robikinkela, from Hybrid Synergy Forum, the team is developing a serie of short videos with the goal to help the new user of HA to learn the application features.
The videos will be periodically published on the YouTube channel of Hybrid Assistant. A new video shall be broadcasted once per week.

The first video, an introduction to Hybrid Assistant, is ready for You on YouTube: "Using the App"

Subscribe to the Hybrid Assistant YouTube channel and stay tuned for new "HA Tips"


A new member joins our Team

The Hybrid Assistant team is growing: Davide Vitali is joining our team.
Davide is an experienced Android developer, with a long list of released apps.
Check his page at @Appsbydavidev.dev or at http://dev.appsbydavidev.it/
The new version of Hybrid Assistant already features his contributions:
- crash dump reporting: if an error occours, HA will ask for permission to send a dump to the developers
- new settings menu
- new settings page
- multilanguage translation (English, Italian, French, German, Spanish)
Other minor enhancements include:
- accelerator position is now displayed
- accelerator color is based on CHG/ECO/POWER meter
- fix for false readings on Prius Prime
- support for Toyota Highlander
- better detection of ICE spinning


LGP tweaking

A creative user from Hybrid Synergy Forum has found a way to use Hybrid Assistant for checking an LGP modified engine that was behaving erratically.
Using the fuel trim chart he helped the tech support to correct settings of the engine LGP control unit.

Full story is available here:

By his suggestion, the new version of Hybrid Reporter now charts fuel trim corrections for each RPM range of the engine.

Here is the map of the misbehaving engine, with very high trims at high RPMs

After tweaking, the trims are back to lower values


LGP fuel quality evaluation

Joshue Martín de Blas, a long time friend of Hybrid Assistant, has put to good use the Fuel Trim charts of Hybrid Reporter.
In his own words:

These 2 Fuel trims graphics are of the same trip, but with different LPG brand. It's clear that in one case the effective Fuel Trim is bigger (and the fuel consumption higher also), because the ECU needs to make much more corrections tho the injection time.

some more information on fuel trims may be found here:
and here:


HV Battery Capacity Estimate

During an HV Check, an estimate of the battery capacity is also shown on screen.
All models (except Prius Plus and Prius Plugin) have a nominal 6.5 Ah battery capacity.
To evaluate capacity follow these guidelines:
1) be sure to have at least 60% SOC, engine and battery at operating temperatures (i.e. not too low or too high)
2) park the car
3) start A/C at the lowest temperature, to put some load on the battery
4) be sure the petrol engine is not running and have completed S1 phase
4) start HV Check
5) keep the check running until actual SOC is at least 10% less than the starting SOC

The Estimated Capacity will change color when enough data will be collected.

The same information is present on the report from Hybrid Reporter

New Release

  • Capacity estimate in HV Check
  • Fix for trip data missing during HV Check
  • Changed SOC red color at 42% 

  • Fuel chart with km breakdown
  • Battery capacity estimate
  • Fix for empty fuel chart 

Fuel usage over distance

The Fuel usage over distance chart plots consumption on a distance scale.
The green line shows overall fuel usage starting from the beginning of the trip, while the red histogram depicts local fuel consumptionin every single kilometer of the trip


New Release

  • HV battery temperatore now shows when fuel chart is displayed
  • Fix for inverter and MG temperatures for Prius 2 and RX400h 

  • Increased line thickness in several charts
  • Fixed filled polyline baseline
  • Lowered sample count for plotting average kw/speed 


New Release

New release for Hybrid Assistant and Hybrid Reporter

  • The HV Check screen now shows more info about the ongoing test
  • The EV stats panel now shows EV % while moving or total
  • Brake evaluation for Lexus IS300h is now more accurate
  • Fix for inverter temperature lower bound
  • SOC chart
  • HV Temperature chart
  • HV Delta chart
  • Fix for empty fuel charts
  • EV in motion
  • Option for full VIN display
  • Average speed over total trip
  • Average EV speed
  • BSFC color scale


Voltage Delta Chart

The Voltage Delta chart plots voltage differences between blocks.
The bottom area plots delta value between maximum and minimum values.
Min, Max and average values are also plotted.
If the average value is not roughly halfway between min and max, we may have a block balancing issue.

HV Battery Temperature Chart

The HV Battery Temperature chart plots temperature sensors values during an HV Check.
Common thresholds (fan and EV disable) are also shown, along with current.

Block Values Chart

The Block values chart plots individual battery block voltage values.
SOC % level is also shown


New Release

New versions for Hybrid Assistant and Hybrid Reporter


  • HA can now use miles, gallons and farheneit temperature
  • Accelerator pedal readings for Prius 4 and C-HR
  • Display of time while moving or total trip time
  • Added option for complete reset in settings screen
  • Status bar is now black
  • Fix for size of AVG/INST labels


  • HR can now display miles, gallons and farheneit temperature
  • Odometer
  • Time in motion
  • CCL and DCL chart
  • Fix for HV fitness min/max error


Time in motion

The EV summary panel can now display trip time as total time or just time spent while the car is actually moving.
You can tap the panel to switch between the two information.


You can reset all options back to default with the "Reset All" button.
Note that this will also delete all trips data from the database used by Hybrid Reporter.
Settings will be reset as soon as you restart Hybrid Assistant.

Overseas rejoice

Overseas rejoice! Hybrid Assistant now can display miles and gallons: you can set them in the settings screen