Peter Christy Posted January 7, 2021 Share Posted January 7, 2021 Posted by Andy48 on 07/01/2021 11:25:04: There are three points here. Firstly there is no threshold as such to determine a minimum safe level of battery discharge. Its a sliding scale. Personally I prefer to land well before the batteries get down to their minimum, and that seems to pay in terms of battery life. Secondly, the ESC measures the whole battery voltage, not the individual cells. It may well be that one cell that is beginning to show its age will drop voltage under load more than the rest. This would mean that this cell could well be stressed even further. Finally, flying from a normal flying field I always like to have a usable reserve of battery power. I find it not uncommon to plan my landing and find another flyer is having difficulty and needing the field clear for their landing. I'm not sure I agree with you about there being a specific safe level of discharge. All manufacturers provide a figure for this in their specifications, and every ESC I have bought has always had its safe threshold voltage set slightly above the manufacturer's recommended safe minimum. Given a choice, I too prefer to land when I have some reserve for a go-around. However, those of us who learned to fly in an era when dead-stick was the norm do not find the procedure particularly alarming or difficult. Full size pilots regularly train for events like engine failure on take-off. Loss of power at any point in the flight is something for which any competent pilot should be prepared. None of my electric models have cell-level voltage monitoring - not even the helicopters. Only two have telemetry voltage monitoring (built in to the ESC), and I do NOT rely on it! I rely on knowing the average consumption and set a timer accordingly. I usually start my landing approaches with 1 min left on the timer, and the timer set to allow me to land with around 35% remaining, according to a battery checker. I usually check remaining capacity with a cell checker when I remove the battery. This, and doing a subsequent balance charge, will quickly reveal any ageing or weak cells long before they become an issue. Continuing flying with a pack with a known weak cell is comparable to continuing to fly with leaky fuel / pressure lines in an IC model. You will get what you deserve! IMHO we have become far too reliant on telemetry systems in recent years. We now rely on technology to save us instead of basic checks and common sense. -- Pete Quote Link to comment Share on other sites More sharing options...
Mike Blandford Posted January 7, 2021 Share Posted January 7, 2021 Hmmm, lots of suggestions, but very few addressing the original problem, which is the ACCESS RX6R is not "talking" to the (known working) MLVSS. As such, I doubt it will "talk" to a current sensor either. Following the report from Dave S., I suggest going into the receiver options and changing the FPort option to on, wait a few seconds to allow the change to be sent to the Rx, then change it back to off (again wait a few seconds), then see if the SPort then works with the MLVSS (possibly power cycle the Rx). GG, are you saying you don't have a receiver options menu? I believe a link to it should appear if you select the receiver name in the protocol menu, along with things like "Bind", "Reset" and Delete". I don't use openTx (I use erskyTx), but I copied the functionality from openTx, and I thought the popup list was there from the start of ACCESS support. Mike Quote Link to comment Share on other sites More sharing options...
Peter Christy Posted January 7, 2021 Share Posted January 7, 2021 Mike, you are quite right about the receiver options menu. I haven't seen it documented anywhere, and only came across it recently when setting up a stabilised receiver for a fellow club member. (I had to use it to re-map some channels in the receiver) You highlight the receiver name and press enter. That should bring up an additional menu. I think the receiver has to be powered and bound for it to work (working from memory - I don't have it in front of me). I'm not sure when it was introduced into OpenTx, but its certainly there in the current release. If GG is running an older release, he may not have it. -- Pete Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted January 7, 2021 Share Posted January 7, 2021 I removed some posts gents can we now keep it civil please, the thread is informative and helping people, lets keep it that way. Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted January 7, 2021 Share Posted January 7, 2021 John, you read my mind! I've just checked and Peter is spot on, click on the name of a bound receiver, eg the name opposite Receiver 1, and select 'Options'. The reciever does need to be powered on to access the current options. Quote Link to comment Share on other sites More sharing options...
Mike Blandford Posted January 7, 2021 Share Posted January 7, 2021 I think the receiver options have always been present from when ACCESS protocol was first implemented in openTx. Receiver options were already present in the ACCESS protocol between the radio and the module when I first received a specification of the protocol. I believe this was before ACCESS was actually released, as I received several updates to the specification later. Mike Quote Link to comment Share on other sites More sharing options...
Andy48 Posted January 7, 2021 Share Posted January 7, 2021 Posted by Peter Christy on 07/01/2021 11:54:22: I'm not sure I agree with you about there being a specific safe level of discharge. All manufacturers provide a figure for this in their specifications, and every ESC I have bought has always had its safe threshold voltage set slightly above the manufacturer's recommended safe minimum. Given a choice, I too prefer to land when I have some reserve for a go-around. However, those of us who learned to fly in an era when dead-stick was the norm do not find the procedure particularly alarming or difficult. Full size pilots regularly train for events like engine failure on take-off. Loss of power at any point in the flight is something for which any competent pilot should be prepared. None of my electric models have cell-level voltage monitoring - not even the helicopters. Only two have telemetry voltage monitoring (built in to the ESC), and I do NOT rely on it! I rely on knowing the average consumption and set a timer accordingly. I usually start my landing approaches with 1 min left on the timer, and the timer set to allow me to land with around 35% remaining, according to a battery checker. I usually check remaining capacity with a cell checker when I remove the battery. This, and doing a subsequent balance charge, will quickly reveal any ageing or weak cells long before they become an issue. Continuing flying with a pack with a known weak cell is comparable to continuing to fly with leaky fuel / pressure lines in an IC model. You will get what you deserve! IMHO we have become far too reliant on telemetry systems in recent years. We now rely on technology to save us instead of basic checks and common sense. -- Pete Firstly, that "specific safe level of discharge" simply does not exist. Its all about battery life. You can discharge down to zero, but your battery will be very short lived. Battery life depends on 5 main factors, charge level, discharge level, storage conditions, number of charges/discharges, and temperature. Most are interlinked. However, it is a fact with most, if not all, rechargeable batteries, that the higher the residual battery capacity before recharging the longer the battery life. Also, we all know to take any battery specification with a very large pinch of salt. I find it quite insulting that you suggest those of us use telemetry have left common sense and basic checks behind, especially considering you have never seen how I prepare and fly my models. Indeed the opposite is certainly true in my case, and I suspect all of us that use telemetry to a greater or lesser extent. Telemetry greatly enhances those basic checks. Lets take range checks. Yes I always do a ground check with a new model and from time to time thereafter. However, nothing beats looking at the range telemetry after a couple of proving flights. Here one can see every dip in the signal strength throughout the flight to ensure that in normal flight, the plane is safe to fly. Ongoing range telemetry warnings also ensure that every flight remains safe, as a sudden warning when flying in a known place and orientation gives cause for investigation. I have had a receiver lose sensitivity over time, telemetry picks it up easily but ground range testing shows a serviceable receiver. You may notice I was talking about using current sensing and not voltage sensing for monitoring battery usage, exactly as Bob suggests. I'm sorry, but a gestimation of capacity used and a simple flight timer is nowhere near as accurate as a current sensor. Yes I still have a flight timer for info, but the capacity telemetry is far more reliable and accurate. The current consumption can change dramatically between flights. Full throttle uses significantly more power than say 2/3 power, and definitely out of proportion to the throttle position. Thus a gentle flight when, say, light conditions are not at their best will give a very different consumption to a flight where the plane is thrown about the sky. Contrary to your point, again the individual cell monitoring is brilliant for picking up a battery starting to fail long before a simple cell voltage check on the ground will show or battery charging will highlight. Frankly most of the simple cell checkers are so inaccurate as to be useless. I've had two of the same make and both gave significantly different readings. Again I find it incredible that you think those of us that have cell monitoring don't also do the things you suggest. Of course, most if not all of us learn to use dead stick landings, BMFA "A" test for instance. Some planes always are landed without power, powered gliders for instance, but that's not the point. Why have a dead stick landing when, through choice, one could have a normal powered landing, other than to keep one's skills sharp? Lets go further and look at other telemetry aspects, monitoring current during a flight of a recently built model to ensure that the motor and ESC parameters are well within limits. Again superior to ground testing with a wattmeter, and before you say it, yes I do use one initially. One can also look at propeller efficiency by monitoring motor speed, current and airspeed. I also can have altimeter telemetry. How do you explain how high 400ft is to a learner, or even an experienced club member? Quote Link to comment Share on other sites More sharing options...
Peter Christy Posted January 7, 2021 Share Posted January 7, 2021 Andy: I'm sorry if you found my comments offensive or insulting. They certainly were not intended to be. But quite honestly, I have observed a recent trend - and I'm sure I'm not alone - for pilots to spend more time worrying about telemetry alarms than actually flying the model! I cannot remember the last time I suffered a loss of signal, but it must have been back in the days of 27 MHz, and probably before the advent of readily available proportional radio! My current fleet of models is split roughly 50/50 between IC power and electric. I have recently taken to converting very old, and usually large, helicopters to electric. Many of these are museum pieces, yet I have never found the need for either cell voltage monitoring, or even current monitoring EXCEPT when doing the initial setup. Unlike an aeroplane, on a helicopter you can't easily change gear ratios or prop size, so the KV rating of the motor becomes very important, and this can only be checked by monitoring the current draw. Once sorted, the correct current draw is established, it becomes a known quantity, and timer programming is more than adequate to avoid over discharging the battery. I have an audible warning set for total battery voltage, set to a conservative level, and it has NEVER gone off! Most of my models don't even have that, and yet my batteries seem to survive for several years without issue. I agree that many battery checkers can be erratic, but the one I carry with me agrees very closely with my (quite expensive) charger - to a degree where I am quite happy to trust it as a reliable indicator of remaining charge. And I did say that I use it at the END of the flight, not the beginning, as a check for weak cells - not as "fuel gauge". With all this in mind, I stand by my assertion that for our purposes, anything further is overkill, and really not worth bothering with. -- Pete Edited By Peter Christy on 07/01/2021 16:07:21 Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted January 7, 2021 Author Share Posted January 7, 2021 Funny how threads meander...... Yes, the original problem is that my XR6R does not recognise the MLVSS. The reason I wanted to use the MLVSS was to enable me to make a planned landing when the battery was starting to run down. I currently rely on a timer but this has a few issues: I can use an absolute timer, i.e. x mins irrespective of throttle - often landing with loads of capacity I can use a timer that relies on some relationship between throttle position and time, but it is very basic I use batteries of varying capacity so 'safe flight time is not consistent. I can, but do not want to wait for lvc as: it adds avoidable risk it means I may be inconveniencing club mates who are in a planned landing situation. Final reason is that it is something new to learn! Haven't had chance to do anything with it today - decorating and gardening. GG Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted January 7, 2021 Share Posted January 7, 2021 Yes GG, we've had a few observations that this thread has wandered off topic with some postings having to be removed and we know (all too well!) how easy it is to get a little diverted but while we appreciate that dead stick landings can be the result of allowing a battery to over discharge and telemetry may aid in avoiding them, the discussion of these subjects isn't really relative to this thread. Everyone, please try to keep to the subject of the OP's telemetry problems. Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted January 7, 2021 Author Share Posted January 7, 2021 This is what I see in 'Options' for the bound RX6....think I need to update my tranny.... GG (I thought i had rotated it successfully but i guess not!) Quote Link to comment Share on other sites More sharing options...
Mike Blandford Posted January 7, 2021 Share Posted January 7, 2021 Yes, you are missing the SPort/FPort setting. For the blue LED, setting the 9mS PWM option, waiting a few seconds, then clearing it may get the blue LED to go off. Mike Quote Link to comment Share on other sites More sharing options...
Andy48 Posted January 7, 2021 Share Posted January 7, 2021 Posted by GrumpyGnome on 07/01/2021 17:18:48: Funny how threads meander...... Yes, the original problem is that my XR6R does not recognise the MLVSS. The reason I wanted to use the MLVSS was to enable me to make a planned landing when the battery was starting to run down. I currently rely on a timer but this has a few issues: I can use an absolute timer, i.e. x mins irrespective of throttle - often landing with loads of capacity I can use a timer that relies on some relationship between throttle position and time, but it is very basic I use batteries of varying capacity so 'safe flight time is not consistent. I can, but do not want to wait for lvc as: it adds avoidable risk it means I may be inconveniencing club mates who are in a planned landing situation. Final reason is that it is something new to learn! Haven't had chance to do anything with it today - decorating and gardening. GG Best bet is to use a current sensor and get it to read out the consumption at particular markers, eg 2000mah, 2500mah, 3000mah, or use the momentary switch to give you the consumption on request. - I find the momentary switch really useful and now have 2 by replacing one 2 way switch. This idea probably won't work either though if the SPort is not functional. Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted January 7, 2021 Share Posted January 7, 2021 Is it my eyesight or is there a line 'Telemetry Disabled' with the checkbox ticked? Sounds like a good box to untick as a start! Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted January 8, 2021 Author Share Posted January 8, 2021 Hi Mike, I will give that a go..... Hi Bob, that is just where the cursor happened to be GG Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted January 9, 2021 Author Share Posted January 9, 2021 Morning all I tried Mike's suggestion - no change. Currently trying to update the Tx to OpenTx 2.3.11 but keep getting an error message re unable to write to F://FIRMWARE which I will need to fix....... After working for 35 years in IT, I am disappointed I am encountering so many 'user error' issues......, although to be fair, I don't spend all day, 5 days a week with it GG Quote Link to comment Share on other sites More sharing options...
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