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Help! Can't charge my Lipo

RC6-VSR displaying cell voltage error

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Mike Blandford11/07/2020 16:06:00
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646 forum posts
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You haven't mentioned what radio gear you are using. Many modern radios include telemetry back from the model. With suitable sensors you can get the flight pack voltage and the motor current displayed (and even spoken). This may well avoid the need for a wattmeter. I have one, but haven't used it for a long time as I use the telemetry.

Recently I've started using FrSky Neuron speed controllers with FrSky radio gear. The Neuron has built in sensors and sends voltage, current, RPM, capacity used and temperature back.

Mike

David Ramsden11/07/2020 18:40:11
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27 forum posts
13 photos

Thanks Keith and Geoff.
Okay. I'm convinced. Please can you recommend a good value Watt meter for electric models? What make/model do you use?

PS I am using a new Futaba T6K and for this model I bought the upgraded receiver and extra cable for monitoring the Lipo voltage in flight (although I'm not using that bit yet - still need to solder it in to the esc cables).

I just did the maiden flight(!). Noticed that the motor was constantly windmilling during the glide. Looks like esc braking is my next challenge(!) and should probably be the subject of a new conversation thread.

Thanks
David

Edited By David Ramsden on 11/07/2020 18:47:08

Edited By David Ramsden on 11/07/2020 18:48:50

Richard Clark 211/07/2020 18:53:43
424 forum posts
Posted by David Ramsden on 11/07/2020 18:40:11:

Thanks Keith and Geoff.
Okay. I'm convinced. Please can you recommend a good value Watt meter for electric models? What make/model do you use?

PS I am using a new Futaba T6K and for this model I bought the upgraded receiver and extra cable for monitoring the Lipo voltage in flight (although I'm not using that bit yet - still need to solder it in to the esc cables).

I just did the maiden flight(!). Noticed that the motor was constantly windmilling during the glide. Looks like esc braking is my next challenge(!) and should probably be the subject of a new conversation thread.

Thanks
David

Edited By David Ramsden on 11/07/2020 18:47:08

Edited By David Ramsden on 11/07/2020 18:48:50

Yippee!!! Success. (The braking should be in the ESC instructions (maybe in a 'glider' section if it has one) and is not usually the default so you will need to set it to 'on'.

My wattmeter is distributed by J Perkins Distribution (who don't sell direct,  only to model shops, physical  and online)  and is called the EnErG Power Analyser and it's fine. It's got Deans sockets at each end so you would probably  have to make up a short 'plug to plug' lead for  the  battery (power input)  end.  You can also use it as a balancer (if you can find a suitable lead) and a battery checker but I've never tried either.

Edited By Richard Clark 2 on 11/07/2020 19:06:50

Edited By Richard Clark 2 on 11/07/2020 19:12:36

EarlyBird11/07/2020 18:53:54
204 forum posts
163 photos

Well done Dave

I am looking forward to your braking thread as it is on my list of what I need to do.

Steve

EarlyBird11/07/2020 19:06:21
204 forum posts
163 photos

This is how to brake.

How to set brake on.

He does it a 5 min.

Looks easy.

Steve

EarlyBird11/07/2020 19:18:06
204 forum posts
163 photos

How to set the brake

Another one with a better explanation of the beeps.

Steve

Keith Miles 211/07/2020 21:21:42
422 forum posts
6 photos
Posted by Mike Blandford on 11/07/2020 16:06:00:

You haven't mentioned what radio gear you are using. Many modern radios include telemetry back from the model. With suitable sensors you can get the flight pack voltage and the motor current displayed (and even spoken). This may well avoid the need for a wattmeter. I have one, but haven't used it for a long time as I use the telemetry.

Recently I've started using FrSky Neuron speed controllers with FrSky radio gear. The Neuron has built in sensors and sends voltage, current, RPM, capacity used and temperature back.

Mike

Telemetry is all well and good if you are prepared to buy and fit the necessary sensors or the type of ESC you describe to each and every model and it can be fully justified as opposed to it being just a fancy and unnecessary additional gizmo.

Each to their own, but I also prefer not to have too many potential distractions when I’m flying! I prefer to pay attention to what I and the model are doing rather than be tempted to pay undue amounts of attention to the transmitter.

Also, for some, a wattmeter, being a universal device, is simpler, perfectly adequate and probably more cost effective especially if you only fly models that are already set up or fitted with the recommended components which should not need in-flight monitoring.

Beginners are also better off with simplicity than complexity, in my view.

David Ramsden11/07/2020 21:53:02
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27 forum posts
13 photos

Thanks Early Bird for the info on setting the esc brake on. Looks easy. I'll do it in the morning. She already glides well and hopefully without the windmill she should float even better.

Just went out for an evening flight and tried constant power just to see how long the 1600mah would last. Managed 17 mins continuous running mostly at 50% throttle some 100%. Is 17 mins good? After that the lipo was slightly warm and the esc cool.
On this afternoons maiden flight, which was actually three shortish flights, the 1600 battery managed 5 full power climbs to about 250' and about 8 mins of half throttle.
I'm guessing the 2900mah (when I get a good one!) will last nearly twice as long.

Enjoyed my first-ever day of electric flights.
Thanks for the help everyone.
David

Mike Blandford11/07/2020 22:12:22
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646 forum posts
25 photos

Keith: I use audio reports so don't need to look at the Tx while flying. Most are enabled by a switch so I can turn them off. The one item I find most useful is capacity used. That way I know how much battery is left.

Mike

Keith Miles 211/07/2020 22:44:56
422 forum posts
6 photos

David, sounds very good indeed as long as you didn’t over-discharge the Lipo! Unlikely if you have a working voltage cut-off in the ESC, something which is probably best not tested in the air! As far as I am aware, if this cuts in, the motor should stop but leaving just enough power for the receiver and servos to get you back to terra firma!

A point about battery capacity checking, something which has come up in this forum in the past. The capacity check facility is a bit of a misnomer because it is, in fact, measuring voltage and, as such, is not as reliable or accurate as monitoring the amount of charge (mah) that you put back into the battery after a flight. There is no means of measuring capacity directly whatever you might hear to the contrary.

On battery care, and opinions may differ, I would say keep no less than 25% capacity in reserve in order to extend the life of your batteries, more if possible. Discard any Lipo with any cell at 3v or less. Never charge Lipo cells above 4.2v (correct charger setting will prevent this). Use “Balance Charge” for all multi-cell Lipos. Do not store Lipos discharged. Do not store fully charged Lipos for more than a few days but use the “Storage Charge” facility of your charger (it is there for a reason). And Lipos are not dangerous if you treat them with due respect and care!

Oh, and warm, or cool, components are fine. Hot ones aren’t!

Happy landings!

Edited By Keith Miles 2 on 11/07/2020 22:50:08

Keith Miles 211/07/2020 22:57:36
422 forum posts
6 photos
Posted by Mike Blandford on 11/07/2020 22:12:22:

Keith: I use audio reports so don't need to look at the Tx while flying. Most are enabled by a switch so I can turn them off. The one item I find most useful is capacity used. That way I know how much battery is left.

Mike

Again, fine, if you have a suitably capable transmitter, or are willing to buy one!

EarlyBird12/07/2020 08:08:18
204 forum posts
163 photos

David

17 min is excellent on a 1600mah battery. Yes a 2900 will last 1.8125 times as long if you fly exactly the same and conditions are the same that gives 30 min. But as the bigger battery is heavier the flight time will be reduced slightly.

The way I work is to aim for a 3.8v/cell target link my timer to the throttle use, set the timer down at 5 min then fly. Check the voltages after and adjust the timer accordingly. Fly again test adjust timer fly again..... a reiterative process that works for me.

For me the flight time I achieve is not important I focus on the post flight battery cell voltages thereby extending the life of my batteries, I hope. This advice came from an experienced pilot who showed me his four year old batteries with no swelling and no loss of power. He also takes his batteries home and puts them on storage charge never leaves them fully charged. Following this advice my batteries are two years old have had hundreds of flights and are still good. Except for one that was damaged when I destroyed my first Riot.

With regard to the number of batteries needed. I was told three was the minimum, one in the plane one cooling down after flying and one on charge. So I bought four to make sure, but that's me being over cautious again.

If you are slope soaring and some distance from your car and charger then you need as many as the number of flights you intend to do. On that basis I bought eight. I had not allowed for flight times being extended as in the right conditions the motor will not be used all of the time.

How you set the brake could be different mine is that model in the link. I searched for 'Volantex Phoenix 2000 esc brake'.

Hope this all helps.

Steve

Piers Bowlan12/07/2020 10:30:40
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2167 forum posts
53 photos

I would say a Watt meter is pretty essential for anyone even dabbling in electric flight. How do you know what current your setup (prop/motor/ESC/battery) is drawing without one? This knowledge will pay for itself by avoiding burning out motors and ESC's. as well as finding a combination that will be reliable and efficient. They can be very cheap like this one or you can pay a lot more but essentially they do the same job. This one is much nicer! wink 2 Alternatively, here but you might have to wait a while for it to arrive!

I switched to XT60 (and XT90 for higher Amps) connectors for all my LiPos after using Deans for years. Tip:- always plug male to female connectors together when soldering and use a big soldering iron as the heat will wick away very quickly along the wires otherwise. You need to be quick to avoid melting the plugs. I also prefer leaded solder, not led free.

Just my 2p worth.

 

Edited By Piers Bowlan on 12/07/2020 10:48:33

EarlyBird12/07/2020 11:12:19
204 forum posts
163 photos
Posted by Piers Bowlan on 12/07/2020 10:30:40:

I would say a Watt meter is pretty essential for anyone even dabbling in electric flight. How do you know what current your setup (prop/motor/ESC/battery) is drawing without one? This knowledge will pay for itself by avoiding burning out motors and ESC's. as well as finding a combination that will be reliable and efficient. They can be very cheap like this one or you can pay a lot more but essentially they do the same job. This one is much nicer! wink 2 Alternatively, here but you might have to wait a while for it to arrive!

Edited By Piers Bowlan on 12/07/2020 10:39:03

Although this is good advice and I do understand your reasoning.

I don't have a watt meter and never had a problem but then all of my setups are either RTF or follow the recommendations for ARTF. I have witnessed what happens when a setup is over propped, smoke!. Yes if one wants to indulge in this experimental way of working or maximum efficiency is important then again yes a watt meter is essential.

The problem I have with this technology is that my old brain does not understand so for me it is simple if I want to fly longer I fit a higher capacity battery. But considering my maximum concentration span is six min long flight times are not an issue for me.

It is time for me to go flying.

Steve

David Ramsden12/07/2020 23:55:26
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27 forum posts
13 photos

Well I guess this thread is drawing to a close now. It's been an education. I've learned a lot about lipos, charger use, and performance monitoring gadgets. And as a small bonus, I got my esc to apply its brake without any trouble at all. Once I had her (my new Kloudrider) trimmed to glide at minimum sink rate I even discovered that it's possible to slope soar without a slope(!). But that's another story...

Thank you everyone!

David

20.jpg

Edited By David Ramsden on 12/07/2020 23:59:09

Edited By David Ramsden on 13/07/2020 00:06:36

Richard Clark 213/07/2020 00:50:12
424 forum posts
Posted by Keith Miles 2 on 11/07/2020 21:21:42:
Posted by Mike Blandford on 11/07/2020 16:06:00:

You haven't mentioned what radio gear you are using. Many modern radios include telemetry back from the model. With suitable sensors you can get the flight pack voltage and the motor current displayed (and even spoken). This may well avoid the need for a wattmeter. I have one, but haven't used it for a long time as I use the telemetry.

Recently I've started using FrSky Neuron speed controllers with FrSky radio gear. The Neuron has built in sensors and sends voltage, current, RPM, capacity used and temperature back.

Mike

Telemetry is all well and good if you are prepared to buy and fit the necessary sensors or the type of ESC you describe to each and every model and it can be fully justified as opposed to it being just a fancy and unnecessary additional gizmo.

Each to their own, but I also prefer not to have too many potential distractions when I’m flying! I prefer to pay attention to what I and the model are doing rather than be tempted to pay undue amounts of attention to the transmitter.

Also, for some, a wattmeter, being a universal device, is simpler, perfectly adequate and probably more cost effective especially if you only fly models that are already set up or fitted with the recommended components which should not need in-flight monitoring.

Beginners are also better off with simplicity than complexity, in my view.

I'm far from a beginner but I don't bother with telemetry at all and don't intend to, even though my chosen make of radio (Multiplex) was the first 2.4 radio to have it and it was inbuilt from day one..

It's just gizmology.

I've been flying RC since the 1960s and have never had a radio caused crash. Or "You are using 60 amps and the RPM is 9 thousand." So what?

PS: Why do they have rev counters on automatic cars?

Richard Clark 213/07/2020 01:01:00
424 forum posts
Posted by David Ramsden on 12/07/2020 23:55:26:

Well I guess this thread is drawing to a close now. It's been an education. I've learned a lot about lipos, charger use, and performance monitoring gadgets. And as a small bonus, I got my esc to apply its brake without any trouble at all. Once I had her (my new Kloudrider) trimmed to glide at minimum sink rate I even discovered that it's possible to slope soar without a slope(!). But that's another story...

Thank you everyone!

David

20.jpg

That's real nice

EarlyBird13/07/2020 07:29:50
204 forum posts
163 photos

David

What a beauty!

Another one on my to do list, I think.

I also went flying yesterday and two members were having a discussion regarding a new Radian that was wind milling.

'You need an esc programming card, I have one at home which I will bring next time'

So having just read up on how to do this I was able to explain how to do it using the sticks. Amazingly it worked first time and he was dead chuffed. I was also pleased but this made me think are all esc programmed the same and indeed are they all made in the same factory and badged for different suppliers? But then as you say that is another story.

You are welcome!

Steve

Dickw13/07/2020 10:10:19
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737 forum posts
99 photos
Posted by EarlyBird on 13/07/2020 07:29:50:..........

I also went flying yesterday and two members were having a discussion regarding a new Radian that was wind milling.

'You need an esc programming card, I have one at home which I will bring next time'

So having just read up on how to do this I was able to explain how to do it using the sticks. Amazingly it worked first time and he was dead chuffed. I was also pleased but this made me think are all esc programmed the same and indeed are they all made in the same factory and badged for different suppliers? But then as you say that is another story.............

Steve

Steve

To answer your questions -

No, all ESCs are not made by the same manufacturer, but some factorys do make the same ESCs with different badges for different "brand names".

Most ESCs follow the same "throttle high at connection" to enter the programming mode, but the tones and programming sequence that follow may vary with products from different manufacturers, and possibly even between different models from the same manufacturer.

It is important to read the manual for whatever product you have if using "stick programming".

Dick

Edited By Dickw on 13/07/2020 10:11:01

EarlyBird13/07/2020 10:16:00
204 forum posts
163 photos

Dickw

Thanks that's good information.

Steve

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