Receiver Low Voltage Detection - what is the solution?

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gandalfnz

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Hello Guys

I have just had my Kyosho S3 crash into the curb, luckily the wheel took the hit, and just broke off, everything else is ok.
I thought it was a write off when I head something crack.

Anyway, this is the second time this happened to me, and I use FS GT5 TX with FS-BS6 receivers. They are not even that cheap, and to be honest are very well made.

Whats pissing me off, is that the batts are not even that flat, and receiver just stops responding.
I am using 4AA NiMh batts, voltage was 5.2 at the time of crash.
Is there any sort of low voltage fail safe I should be using, surely this should have been built in, in the receiver itself?

Thanks
 
Just get a modern battery. Or use 5 NiMHs.
 
What kind of batteries are you using? Just because your batteries are delivering 5.2v at rest, that doesn't mean they are delivering that under load. Maybe get a small 2s LiPo and run a BEC to ensure you are delivering a constant voltage to your receiver.
 
Depending on your servo(s), maybe you don't even need a BEC. Or you can use a lower voltage chemistry such as LiFePo.
The receiver can take up to 2s lipo (8.4V). If your servos can take it, get some 2s packs and that's it.

Failsafes are meant to react to loss of signal. Nothing you can do if the Rx goes haywire itself due to low supply voltage...
 
I think there used to be some name brand ones many years ago. I used to use the ofna micro ones, not sure if they monitor voltage or not.

Here's one that might:
https://www.amazon.com/BQLZR-Black-4-8V-6V-Nitro-Accelerator/dp/B00LVHGSIY

Your best option is to get a 2/3A NiMH 5 cell 6V pack/charger. They don't cost much and a 1600mah hump/flat pack will last all day usually unless you have some unforgiving servos.

According to the "extensive" manual, this one will kick in at 3.8V:
https://www.horizonhobby.com/product/micro-fail-safe-unit/DTXM4000.html

Manual:
2022-0715-DTXM4000-manual-duratraxFailSafe.jpg



This one does it too:
http://www.spektrumrc.com/Products/Default.aspx?ProdId=DYN2553

But it was replaced with this one:
https://www.horizonhobby.com/product/micro-fail-safe/DYNR0101.html

That ones manual doesn't say anything about low voltage. Only signal loss.

There are probably others still out there. Just what I found with a quick search.
 
Last edited:
Thank you for taking the time to post all this info.

I will def look into getting one of these.

Thing is, the standard 4 pack gives me 2.5 Ah capacity, while all the lipo packs small enough to fit into battery compartment are all around .8 Ah. Big difference, which is why I preferred to stay with NiMH.
 
Well, you could at least upgrad to a 2/3A 6V NiMH pack. A 2/3A 5 cell hump pack usually fits in whatever area a 4xAA pack fits. Then at least your starting out with more volts. A decent 1500-1600mah 2/3A pack will give you enough run time for 1000cc's of fuel at least usually and be able to supply more current for your servo than an AA cell can.

You can get one pretty cheap with a wall charger if you don't have a NiMH charger that goes down to 1amp:
https://www.amazon.com/Powerhobby-1600mAh-Receiver-Battery-Charger/dp/B07GH882PW

I still run those in my 2 nitro revo's, they use 2/3A flat packs. I haven't bothered to try getting bec's and a lipo for them due to the fact that I rarely drive them. When I do, they usually break something well before the pack runs out. lol!
 
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