FlySparkINAV setup guidesUpdated Energy left for home
The energy card is how INAV decides it still has enough left for the trip home. It is three numbers: a battery reserve, power at cruise, and power at idle. The footer says INAV uses the power figures to estimate remaining flight time and distance.
Battery reserve for return runs from 0 to 100%. The demo starts at 5%. The hint says return when the energy left drops to what the trip home needs, plus this margin. A bigger reserve turns for home while more is still in the pack.
This is INAV return home, not Betaflight GPS Rescue. Speeds, the two-stage climb and safehomes are their own cards. This one is only the energy estimate.
Free. Hardware connections need Chrome or Edge on a computer; phones use the FlySpark app.
- Free
- Nothing to install
- Demo without hardware
In short
The energy card tells INAV when a return should start. Battery reserve is 0 to 100%, and the demo starts at 5%. Cruise and idle power are watts read from a log, and the card is hidden if the board has none of these settings.
Key facts
- The card is Energy for the trip home, on INAV Advanced nav. It is not Betaflight GPS Rescue.
- Battery reserve for return is 0 to 100%. The demo starts at 5%.
- Return starts when energy left drops to what the trip home needs, plus this margin.
- Power at cruise is watts to one decimal, in steps of 1 W. The demo starts at 0.
- Power at idle is watts to one decimal, in steps of 0.5 W, from 0 to 655.35 W.
- Read cruise from a calm cruise in a log, and idle from idle. INAV estimates time and distance from them.
- The card is hidden when the board has none of reserve, cruise power or idle power.
- Chrome or Edge uses USB or Bluetooth. iPhone has no USB host.
Betaflight
INAV
ArduPilot
PX4- BLHeli_S
Bluejay
AM32
ExpressLRS
EdgeTX
DroneCAN
MAVLink
Try it
Turn for home
This picture treats the trip home as 20%. Return when energy falls to that plus the reserve.
Keep flying
Turn at 25%
FlySpark
Features
- 01
A margin on the way home
Reserve is the extra percent kept on top of the energy the trip home needs. 0 to 100%. The demo starts at 5%.
- 02
Power at cruise
Watts, to one decimal, in steps of 1 W. Read it from a log of a calm cruise. The demo starts at 0.
- 03
Power at idle
Watts, to one decimal, in steps of 0.5 W. The field runs from 0 to 655.35 W. Read it from idle in the same log.
- 04
Time and distance
INAV uses those two power figures to estimate remaining flight time and distance. They are not a battery voltage alarm.
- 05
Hidden if the build lacks them
The card appears when the board has at least one of the three settings. With none of them, the card is not shown.
- 06
Not the pack voltage
Cell voltage and capacity are the battery page. This card is the return estimate on Advanced nav.
What the reserve actually does
The label is Battery reserve for return. The hint under it is the whole rule: return when the energy left drops to what the trip home needs, plus this margin. The margin is a percent, from 0 to 100, and a new demo board starts at 5.
Raise it when the route home is uncertain, or when you want to be on the ground with more left in the pack. At 0 the margin is gone, and the decision sits on the trip-home estimate alone. At a high number the turn comes early, while the pack is still well up.
The try-it on this page is a picture of that sentence. It treats the trip home as 20% and adds your reserve. It is not the firmware's own sum, and it does not read a pack. The real threshold is what INAV computes from the power figures and the path home.
Cruise watts and idle watts
Power at cruise and power at idle are what the estimate is built from. The footer says to read them from a log of a calm cruise and from idle. A guess that is far from the craft makes the time and distance estimate far from the flight.
Cruise is shown in watts, to one decimal, and the step is 1 W. Idle is watts to one decimal, and the step is 0.5 W. Idle runs from 0 to 655.35 W. Both demo values start at 0, which is not a cruise. Put the numbers from the log in before you trust the estimate.
These are not the current sensor scale on the battery page, and they are not a blackbox sample rate. A blackbox log is a good place to read a calm cruise and an idle, then type the watts here. The logging CSV on this device is a lighter look at voltage and amperage if you do not have a blackbox file yet.
The card is shown when the board reports any one of the three settings. A build with none of them hides the card. There is nothing to type until the firmware has the settings.
Where this sits among the other return controls
Advanced nav has a separate Return home, advanced card for the two-stage climb, the descent on the way, and path retrace. Basic return altitude and landing are on the failsafe settings. Safehomes are extra landing sites. None of those replace these three energy numbers.
A safehome changes where return goes. The reserve changes when return starts. You can use both. A site that is in range does not change the percent you keep for the trip.
Betaflight GPS Rescue has its own altitude, climb and ground speed. It does not read this INAV reserve. Do not copy a GPS Rescue number into cruise watts.
Where you set it
Open Advanced nav on an INAV board and find Energy for the trip home. Chrome or Edge connects over USB or Bluetooth. Android adds Wi-Fi. iPhone uses Bluetooth or Wi-Fi and has no USB host.
Set the reserve first, then replace the two zero power figures with the log. Fly a short, calm cruise before you trust a long route to the estimate.
FlySpark
Set the return energy
Open the card
On an INAV board, open Advanced nav and find Energy for the trip home. If the card is missing, this build has none of the three settings.
Set the reserve
Battery reserve for return is 0 to 100%. The demo starts at 5%. Higher turns for home sooner.
Read the log
Take power at cruise from a calm cruise, and power at idle from idle. Cruise steps by 1 W. Idle steps by 0.5 W.
Leave the other return cards
Climb, descent and safehomes are separate. This card only feeds the time and distance estimate.
Troubleshooting
Common problems and fixes
Problem
The energy card is missing
Fix
The board reported none of battery reserve, cruise power or idle power. The card stays hidden until a build has at least one of them.
Problem
The estimate looks wrong
Fix
Cruise and idle start at 0 in the demo. Read watts from a calm cruise and from idle in a log, then enter them.
Problem
Return starts too late
Fix
Raise the battery reserve. It is the margin added to the energy the trip home needs, from 0 to 100%.
Problem
Idle will not go as high as cruise
Fix
Idle tops out at 655.35 W, in steps of 0.5 W. Cruise is a separate field, in steps of 1 W.
FAQ
Frequently asked questions
What is the INAV energy card?
Energy for the trip home. A battery reserve, power at cruise, and power at idle. INAV uses the power figures to estimate remaining flight time and distance.
What does the battery reserve do?
Return starts when energy left drops to what the trip home needs, plus this margin. It is 0 to 100%. The demo starts at 5%.
Where do cruise and idle watts come from?
A log. Cruise from a calm cruise, idle from idle. The footer says to read them that way. The demo starts both at 0.
What are the idle limits?
0 to 655.35 W, shown to one decimal, in steps of 0.5 W. Cruise steps by 1 W and is also shown to one decimal.
Is this a low-voltage alarm?
No. Cell voltage and capacity are the battery page. This card is the return estimate.
Is this GPS Rescue?
No. GPS Rescue is Betaflight. This reserve is INAV return home, on Advanced nav.
Why is the card missing?
The board has none of the three settings. The card is drawn only when at least one of them is present.
Does a safehome change the reserve?
No. A safehome changes where return goes. The reserve changes when it starts.
Does the picture on this page fly the craft?
No. It treats the trip home as 20% and adds the reserve, so you can see the margin move. INAV does the real estimate from the power figures.
Can I set this in Chrome?
Yes, on INAV. Chrome or Edge uses USB or Bluetooth. Android adds Wi-Fi. iPhone uses Bluetooth or Wi-Fi and has no USB host.
References
Sources
The official documentation behind the background facts on this page.
- INAV WikiINAV on GitHub · github.com
- INAV ConfiguratorINAV on GitHub · github.com
- Betaflight WikiBetaflight · betaflight.com
