R/C Tech Forums

R/C Tech Forums (https://www.rctech.net/forum/)
-   Radio and Electronics (https://www.rctech.net/forum/radio-electronics-137/)
-   -   Electric problem (https://www.rctech.net/forum/radio-electronics/1095772-electric-problem.html)

Valerio 02-07-2022 01:03 PM

Electric problem
 
Hello everyone,
I have a problem with the electronics of my 1/8 on road, the battery runs out very quickly, less than 1 hour. I currently use Sanwa M17 transmitter, 2 Sanwa PGS-XR2 servos, transponder and 1800mah lipo. I have tried a different transmitter and receiver and the problem is still there so I guess it will be a servo or transponder. Has anyone had a similar problem? Is there any way to detect which servo may be damaged?

Andy Koback 02-07-2022 05:29 PM


Originally Posted by Valerio (Post 15872893)
Hello everyone,
I have a problem with the electronics of my 1/8 on road, the battery runs out very quickly, less than 1 hour. I currently use Sanwa M17 transmitter, 2 Sanwa PGS-XR2 servos, transponder and 1800mah lipo. I have tried a different transmitter and receiver and the problem is still there so I guess it will be a servo or transponder. Has anyone had a similar problem? Is there any way to detect which servo may be damaged?

Are you having a problem with servo not working or running out of battery too soon? 1800mAh is a small battery for 1/8 car. You need something with more mAh.

gigaplex 02-07-2022 08:11 PM


Originally Posted by Andy Koback (Post 15873033)
Are you having a problem with servo not working or running out of battery too soon? 1800mAh is a small battery for 1/8 car. You need something with more mAh.

And even then, don't expect to get an hour's runtime on a single battery.

Valerio 02-07-2022 11:15 PM

Thanks for the answers. The car is 1/8 on road nitro, the battery only powers the servos and transponder. Before having this problem I have done a semi of 20 min and a final of 45 with their respective warm-ups with the same battery. The servos work fine, but there is excessive consumption

Roelof 02-08-2022 02:42 AM

Check the end points. If a servo will lean on them it will draw more current.

1/8 IC Fan 02-08-2022 03:10 AM

Maybe a mod can move this...

billdelong 02-08-2022 10:11 AM

How old is your battery?

If you're not getting the same run time that you used to get, the pack may need to be replaced.


A good way to check the health of your cells is to get IR readings when the pack is new and when the IR fades, then the cells are going to lose capacity and will need to be replaced.

Valerio 02-09-2022 12:30 AM

The endpoints are correct and the batteries are new. Before I used 1400mah batteries and due to this problem I have bought two 1800mah batteries and it fails with both batteries.
I have tried to measure the consumption with an ammeter and the consumption at rest is around 0.15A and exerting force on the car I get to have peaks of 0.6A, so with a 1800mah battery the autonomy should be greater than 1,5 hours

the rc guy 02-09-2022 01:53 AM

could be just cheap batteries.

Roelof 02-09-2022 02:25 AM


Originally Posted by Valerio (Post 15873526)
The endpoints are correct and the batteries are new. Before I used 1400mah batteries and due to this problem I have bought two 1800mah batteries and it fails with both batteries.
I have tried to measure the consumption with an ammeter and the consumption at rest is around 0.15A and exerting force on the car I get to have peaks of 0.6A, so with a 1800mah battery the autonomy should be greater than 1,5 hours

And the brake, not adjusted to full blocking?

Maybe you schould mount a current meter between the battery and the electronics and measure the current in differen situations and configurations. And do a charge/discharge cycle on the battery if it has the noticed capacity.

the rc guy 02-09-2022 03:32 AM

your #;s are wrong .6 amps thats not possible with a steering servo

gigaplex 02-09-2022 03:35 AM


Originally Posted by the rc guy (Post 15873541)
your #;s are wrong .6 amps thats not possible with a steering servo

How is that not possible?

Valerio 02-09-2022 03:54 AM

The batteries are Arrowmax and Sunpadow brand, I donīt consider them to be cheap batteries.
As for the linkage, everything is well adjusted, I don't have much brake, the direction doesn't stop and the carburetor opens just enough.
I suspect a bad servo but it works fine

billdelong 02-09-2022 07:27 AM


Originally Posted by Valerio (Post 15873545)
The batteries are Arrowmax and Sunpadow brand, I donīt consider them to be cheap batteries.
As for the linkage, everything is well adjusted, I don't have much brake, the direction doesn't stop and the carburetor opens just enough.
I suspect a bad servo but it works fine

I agree that it might be the servo, but have you removed the servo horn and verified no binding in any of the steering links? Sometimes the plastic goes out of round and I have to pinch the ball ends with pliers to relieve pressure on the links so they turn butter smooth, you might be losing efficiency there possibly. If the links are good, then it wouldn't hurt to rebuild the gear box on the servo as well, flush all the old grease on the gears while inspecting for any broken teeth that might be binding inside the servo, then apply fresh white lithium grease to rejuvenate your servo efficiency again.


All times are GMT -7. It is currently 01:57 PM.

Powered By: vBulletin v3.9.3.9 Patch Level 3
Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.