Drone outputs power to about 60-70% after raining damage.

Ekaterina · Oct 13, 2020

Hi, my drone stuck on a 9m tall’s tree and got rained for 8hours. Next day amazingly my friend took it back from the tree. Then I kept my drone drying for one night.

As a result, the drone is recovered, and took flights 10 times, and it was fine, very smooth flights. Only problem is I feel drone can only output 50-60% powers than before. I wonder if I should buy new parts or still have room to investigate and fix power issues.

Situations are:
- Drone was 100% wet, and battery was completely dead, 0v. Camera was no damage.
- I dried my drone up for one night.
- I repaired props, prop-guards, and DJI’s Antenna. The antenna’s connector is ripped off from an electric circuit board. Then, I needed to reveal a copper surface on the board scraping by a cutter because the connector is ripped with soldering copper surface together!! Thus I guess this surgery might not work perfectly.
- When plugging to betaFlight configulator, it did not detected. Then, after pushing a reset button on FC, betaFlight configured the drone.
- Then I copied and saved previous BetaFlight setting.

During flight:
- RSSI value used to show 99, but now shows only 45.
- I feel I use higher throttle position than before to fly the drone.(but PID > Rate profile are different.) Also, the drone does not accelerate so much even though punching in throttle harder than before.
- Right now I feel a high risk to fly far away to exam RX strength, so have not tried long distance flight yet .
- battery lasts almost same time, and there is no crazy heat from motors and FC.

Thus, what would you suggest to recover output power? Check something else, or buy some parts? Thanks in advance!

My drone: iFlight - titan DC2, FrSky, DJI-air unit

TITAN DC2 HD Whoop - BNF

Less than 250grams included 4S 450mAh battery No Props or frame in view! Low Resonance frame construction (Less Jello, more Cinematic) DJI FPV Air Unit 720p 120fps FPV feed (record in 1080p/60fps) Butter smooth XING1404 4S Duct prop guards to protect

shop.iflight-rc.com

tevek · Oct 13, 2020

I’m surprised that after one night of drying that you were happy to plug a battery back into it.
Obviously you put a fresh battery on the quad, put exactly the same props on as before (throw the prop guards in the bin, they’re crap and effect the flight characteristics badly).
As for the the receiver antenna base repairs , I would be replacing the receiver as it may fail at any time. The RSSI numbers would worry me.
I didn’t know that there was a reset button on the F4/F7 FC on the DC2 (boot button?). Glad you were able to open up betaflight, if you saved your original CLI file and you put that back into the quad, then at least you have a starting point. I would go to the motor tab in Betaflight (remove your props) and spool up each motor to make sure they are each responding to the slider a and reaching max and min speeds to prove its not the motors or an esc fault.

Ekaterina · Oct 13, 2020

tevek, thanks for your comment.

Yeah, I thought my drone was died 99%, so just tried plugging battery, then worked after one night, lol. But I placed drone and lot of dry rices together into double plastic bags over night.

Can't we trust RSSI value 100%? This is because RSSI might need to normalize values between 0 to 99 for some drones?

I think boot button is right instead of reset button. Anyway, that button make drone recovered to detect betaFlight configurator.

About motor test. I saw R value hit max 70,000 when spool up. However, how do I know Max spin speed from that?

Xing 1404 4600kv

XING X1404 Toothpick Ultralight Build (unibell)

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tevek · Oct 13, 2020

I'm surprised that the battery once discharged to 0% was able to be charged up again. The battery may be faulty in not allowing the motors/escs to draw full current/voltage from the battery and possibly giving you throttle issues.

I am assuming that you fitted the same props to your DC2 ( I have one and the spares I had made the quad extremely sluggish -i'm using 2.5" Avan tri blade props, much better)?

In betaflight, in the motor tab, select the slider to confirm Props Off, and use the individual sliders to confirm each motor spools up between 0 - 2000. That will at least prove your motors and esc's are probably ok.

As for the RSSI, if you are seeing a reading, that means that your AUX channel is set correct and as mentioned before, you may need to replace your receiver as you may have a poor connection after repairs and you risk losing control of the quad and crashing it.

By hitting the boot mode, you have basically forced your quad into DFU mode to update firmware etc. The FC should just connect normally via the USB-C connection and the USB connection on your computer.

Finally, rice is not always the best way to dry out your drone. If you have isopropyl alcohol, use that for dabbing on FC and ESC and other exposed parts.

Ekaterina · Oct 13, 2020

oh, sorry to make you misunderstand. The battery is dead and threw to trash.

Yes, props are same.

motor test, 14.8v (4s) x 4600kv = 68,060 is almost R 70,000 for all 4 motors in motor test, betaFlight. Can I say motors and FC are fine??

yes, I've never touched boot mode and just used ucb-C connection. However, it did not work at that time until hitting the button.

I saw youtube that he was using rice to dry up. Ideally I would use desiccant, or drying agent. That's good to know isopropyl alcohol is also helpful to dry out.

tevek · Oct 14, 2020

Ekaterina said:
oh, sorry to make you misunderstand. The battery is dead and threw to trash.

Yes, props are same.

motor test, 14.8v (4s) x 4600kv = 68,060 is almost R 70,000 for all 4 motors in motor test, betaFlight. Can I say motors and FC are fine??

yes, I've never touched boot mode and just used ucb-C connection. However, it did not work at that time until hitting the button.

I saw youtube that he was using rice to dry up. Ideally I would use desiccant, or drying agent. That's good to know isopropyl alcohol is also helpful to dry out.

It sounds like your motors and escs are fine. I would still look at replacing your receiver if you are not confident in your repairs, or take it out in an open field where you test to see if it failsafes on you and you can retrieve it. As for using rice, there are sometimes issues with grains of rice getting into motors and the like and is generally not used by anyone these days. Probably better with a nice curry instead of near your quad

.
As for the power output, maybe plug the quad back into betaflight and see if you are getting full throttle, yaw etc in the receiver tab. You should be running from 1000 - 2000. A lot of people including myself always trim the mid and end points on every drone to make sure there are no surprises.
Here is a video to help:

Ekaterina · Oct 14, 2020

this morning, I flew my drone. 1st and 2nd flights were great to reach 200m away, 50m height. 3rd flight got RX LOSS at only 20m. Yeah probably I will order a new transmitter. Thanks for your help!!