Intermittent Throttle Mystery on Spektrum 1S Indoor Receiver

[Cliff 1959]

Has anyone else had this problem (see video), it's frustrating to say the least?

[David Hall 9]

That looks as if it is having a brown-out. This is where the battery doesn't have enough output to run the motor without a significant drop in it's output voltage, causing the control to reset. It might improve as the battery is warmed up. Fairly typical of an ageing or poor battery.

[Denis Watkins]

David beat me to it

My throttle does the same on failing cell

A fresh cell normalised the control

Where a normal cell is normally 3.7v

Spektrum Rx shut off at 3.3v

Edited By Denis Watkins on 07/12/2019 20:26:47

[Don Fry]

"'Tis the season of cell failures". That is not receiver brown out, but the motor controller detecting low volts, and cutting/refusing to start the motor. I had two last week, first outing of autumn.

[Cliff 1959]

Thanks for the replies guy but it's not just one battery but all 12, they're all a couple of years old and they all run well in my other six models so I'm thinking it has to be the receiver? It's the AR6400 Spektrum receiver brick by the way. If I try some brand new batteries it works but they're too big for the model, this would suggest that the older batteries, although fully charged and showing 4.2, just aren't cutting it anymore for this particular model!

[Denis Watkins]

Posted by Cliff 1959 on 07/12/2019

this would suggest that the older batteries, although fully charged and showing 4.2, just aren't cutting it anymore for this particular model!

You have it Cliff

All my 1S are not all suitable in all my micro models

You can hear some " brick" types filling up and whirring before flight, just zeroing in

Suggesting more power is required in a particular model

On the multimeter most 1S will show 4.2v even when down on capacity

Some fully inflated almost useless 1S can show 4.0v

[David Tayler]

I check my 1S cells under load. To make a simmple battery checker all you need is a digital volt meter module( less than £2 from China, a push to make switch and a 4.7 ohm resistor. I described this in a letter to RCM&E a few years ago. Failling cells will show 4.2 volts when fully charged, but the voltage collapses under load.

[Cliff 1959]

Well you never stop learning, looks like the plane is ok after all, thanks for the information.

[Don Fry]

Posted by David Tayler on 08/12/2019 09:02:47:

I check my 1S cells under load. To make a simmple battery checker all you need is a digital volt meter module( less than £2 from China, a push to make switch and a 4.7 ohm resistor. I described this in a letter to RCM&E a few years ago. Failling cells will show 4.2 volts when fully charged, but the voltage collapses under load.

I have a crude alternative, I open the throttle, and if the whirry bit don't whirr, or fails to keep whirring, out goes the battery.

[Colin Carpenter]

I agree with that Don !😎We fly a lot of Blade Is helis and quads on Fridays and these cells can be quite annoying ! One week they're ok and next week - clapped out. I buy them from HK when on offer and hope I get 6-12 months from them ! Mark them up so they can be identified ! Colin

[Don Fry]

There is no sense as to their longevity. The cells in this year's failure session were all about three years old. Of a batch of 5, the other three are perfect, giving full flights with a margin left when the timer goes. I just do light fixed wing, so I don't hammer them. I even try to leave them half charged between sessions. But as you say, they decide to go on a wildcat strike, and that's it.

Happy days though, I've just ordered 3 replacements, a bit bigger than the last, proper branded E Flight, less than £20 delivered, with me Tuesday via the postie. 🇫🇷 Lot of fun for that money.