Problem with batteries

Discussion in 'Walkera Rodeo 150' started by Stathis, May 24, 2018.

  1. Stathis
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    Stathis New Member

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    Hello to all
    I have a main issue with batteries from rodeo 150.I have this drone 1 month now and i use one original battery and 4 others (giant power) from ebay. After 10-15 recharges all the batteries last about one minute of flying,but when i put them to my charger it shows that the batteries are on 60% charged!! I bought one more tattoo battery few days ago and from the first flying i had the same problem! I believe that the problem is on the drone and not from batteries.I m thinking to change the Power Board...
    Do any one have this issue or suggest what to do?

     
  2. PicklePilot
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    PicklePilot New Member

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    Are u balance charging the batteries? What charger are you using? I bought an inexpensive charger($35usd) after i had battery issues and i haven't had an issue since. If u have an adjustable charger plug your batteries into the balance port AND main port, set charger to balance charge, set amps to .5, be sure voltage end point is set to 8.4v. If u dont have charger tge one i bought has served me well I'll attempt to post a pic. Its a Turnigy Accucell 6, 80watt 10amp. [​IMG]
     
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  3. bjr981s
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    bjr981s Moderator Staff Member

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    Most likely your charger is not balance charging. Buy a cheap lipo checker and see if all cells are the same voltage.

    Also do not use larger batteries than the OEM battery. They weigh too much and put additional current through the ESC and Motor due to their weight. This can damage the Power board the ESCs and the Motors due to overheating.
     
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  4. PicklePilot
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    PicklePilot New Member

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    This would be due to current draw, correct? A battery with more mah but same weight will not push more current but has more capacity for longer flights granted the discharge rate is the same.

    On my whoops i can tell a difference in flight time with a 220mah lipo vs 150mah lipo of the same weight and c rating. If i fly a 220mah with 25c rating i have less punch with longer flights than a 220mah rated 45c. I have one 45c atm but prefer the power over 30 seconds of flight. On the same note if i was a good pilot the added power would allow longer flights due to not needing to punch but using proper throttle control. In my limited experience weight is the determining factor with battery choice(other than voltage of course). I will choose a larger larger mah battery every time if the weight and dimensions are compatable with the craft. I could be very wrong on this subject but my experience has yet to persuade me to think otherwise.
     
  5. bjr981s
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    bjr981s Moderator Staff Member

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    No this has many falsehoods.

    Extra Battery capacity means increased weight.
    Extra C rating means increased weight.

    Your theoretical battery does not exist. To get a battery with extra capacity and have the same weight you would have to reduce its C rating by using different battery technology. This would mean it could not provide adequate power to the motors without voltage sags.

    This is why I persist with advising people they do not understand what the "C" rating is. And they they are not getting correct performance out of their drones.

    Have look at the Specs of Turnigy Batteries.

    A standard battery will have a weight and C rating for a Given MAH rating.
    A nanotech battery will have a weight and C rating for a Given MAH rating. It will be heavier.
    A graphene battery will have a weight and C rating for a Given MAH rating. It will be heavier still.

    This is also very incorrect. You are ignoring aerodynamics, atmospherical pressure and air density.

    You cannot in anyway compare flying objects be they insects, birds aeroplanes or drones.

    Their is not a linear relationship between power, weight and size. This is why bees defy normal aerodynamic theories. In Theory they cant fly.

    What you can do with a Micro-drone like a Whoop does not define any real relationship for a Walkera or the Vendor Racing drone. As the Drones get bigger the relationship between power and weight is ex;onential.

    Cheers Brian


    Keep experimenting and asking questions here. Its how you learn.
     
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  6. PicklePilot
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    PicklePilot New Member

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    I have many different mah 3.7v batteries i use for my whoops. I typically buy whats on sale and what i can afford while staying within limits of dimension and weight. I have seen Videos where Bardwell tests batteries only to discover most manufacturers ratings other than voltage are averages and rarely match what the battery actually produces. Another very reputable enthusiasts goes as far as to say C ratings are nothing more than marketing and are made up numbers based on the discharge a manufacturer feels their battery produces based in materials and other factors. I understand that a LiPo battery has a certain elemental makeup but as with most elements some are more pure than others.

    My main point and question is that a higher mah battery is often larger therefore puts more strain on a crafts power system hence pulling more current. The mah rating of the battery itself has no bearing on the current flow and the battery will only attempt to put out what it is being asked to deliver. The ability of the battery to keep up with this draw isn't the issue as I'm aware from experience that lag, heat, puffing and even fire can result from over demand.

    I've read post where ppl will advise against the use of a larger mah battery because it will spin the props too fast or the craft will be overpowered when essentially a larger mah battery will most likely only impede performance instead of increase it. I am correct in my assumption that more mah does not allow more power but capacity.

    I come from an automotive background including RC racing cars prior to my new passion for aviation. My analogy on batteries relates to a gas engines fuel system. I understand it like this:

    A)The voltage of a battery is the carburetor or EFI that introduces the fuel mix to the engine or E motor. The larger the carb, delivery system or voltage the more potential power the engine or motor can produce.

    B)The size of the fuel tank is the mah. The more it will hold the longer before it needed refilling or a recharge.

    C)The diameter of fuel lines is the circuitry, connectors and wiring quage. The lines or circuitry can only flow as much as the diameter, guage or lack of resistance will allow.

    D)The fuel pump, injector size, and carb jets are the C rating that allows a certain amount of fuel or current to be introduced into the engine or motor if the circuitry or lines can transfer it.

    I am hoping i am correct because i truly want to understand the basics so i may learn more on the finer details of electronic components. I also hope im correct so that others who think like me but havent been able to relate can undestand a little better as well.

    I try not to speak on what i am not sure of and prefer to learn tgan teach but if asked i do like to help with proper info
     
  7. bjr981s
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    The C rating is not made up. It's just that there is no explanation readily available for how it is calculated. It is the most important rating on the battery. Because people don't understand it they think its not relevant.

    The C rating is dependant on the construction of the cells and the cell material. And the individual, wafer size.

    Your analogies are not correct as there are more interrelationships between the parts you describe. I will use your descriptions and update them so they have the correct relationships.

    A)The voltage of a battery is the carburetor or EFI that introduces the fuel mix to the engine or E motor. The larger the carb, delivery system or voltage the more potential power the engine or motor can produce. Up until you hit the C rating of the battery. Then the Carburettor and all other parts start getting immediately smaller.

    B)The size of the fuel tank is the mah. The more it will hold the longer before it needed refilling or a recharge. For the first kilo of fuel it adds 2 Kilos to the weight to the car. For the second Kilo it adds 4 Kilos of Weight the third 8 Kilos of Weight. The more fuel you add the more exponentially the weight increases. That means that the motor must put out more power. Which it can as the C rating barrier has now been lifted upward. ( at the cost of damage to the drivetrain)

    C)The diameter of fuel lines is the circuitry, connectors and wiring quage. The lines or circuitry can only flow as much as the diameter, guage or lack of resistance will allow. They will only allow up to the C rating of the battery once the C rating is hit they all reduce in size.

    D)The fuel pump, injector size, and carb jets are the C rating that allows a certain amount of fuel or current to be introduced into the engine or motor if the circuitry or lines can transfer it. At the time of a full battery. These components reduce in size as the battery dischargers and the C limit also reduces.

    As you can see using an Automotive analogy does not work very well.

    Matching and Sizing Lipo batteries to a craft and having the correct tuning for the ESCs motors and Props so you get good performance without damaging the components is why Walkera build RTF and BNF models the way they do.

    Wrong the C rating defines the max current a battery will supply before it voltage sags. the formula is MAH /1000 x C

    So 2200mah with 20C is 44Amps
    So 2800mah with 20C is 56Amps

    The asked to deliver is not constant.

    If you replace the 2200mah with the 2800 mah in your drone the weight is now increased that means more strain on the motors to hold in a hover so more current draw from the battery. And as the C rating will allow extra current to flow it will. This overheats the ESCs and Motors. Heat increases the resistance of the parts. So then more current is required to keep the drone hovering. This is called thermal runaway.

    This means that larger MAH batteries will actually last less time than the normal and also damage the components.

    And as I said earlier for a Whoop this is OK but as the aircraft gets bigger this comes more and more into play.

    Remember that with a car you are on the ground. And momentum plays a part (as in Newtonian physics). It takes energy to accelerate and decelerate.

    You can coast. For a drone you have to accelerate at 9.8 metres per Second Squared. Just to stay in a stable hover. As you have to counteract the 9.8 M/S2 force of gravity. Its the Squared that forces the exponential math on components like weight (battery) and energy for a flying drone.

    It not like an aircraft where you have aerodynamic lift from the wings. A drone flies by Brute force.

    I hope you get all this. Im hoping that you will take this new found knowledge and pass it on.

    I cant spend too much more time on this discussion. Have other members to make warm and fuzzy.:rolleyes:
     
  8. PicklePilot
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    PicklePilot New Member

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    U only elaborated on my analogy. In no way did you find any fault in it. If i was to repeat something you say in different words i feel as if you'd disagree only to reword the same statement. The more we chat the less educated i feel. I'm sorry if I'm being harsh but a little knowledge doesn't make you THE authority and everyone else wrong. I have tolerated your delivery up until this last response but as i said it seems that no matter what i say you will say im wrong. If i say purple youll disagree and say violet. Violet is purple to most people. I understand details are important but most often going into particulars makes a person seem pety and conversations or discussions very unpleasant.

    I think I'll find another source of information because you seem to only know as much as i do and instead of helping me understand you would rather dissect my statements and attempt to outsmart me by reworking my statements and going into parriculars that are basic knowledge therefore not mentioned by me.

    I understand physics. Physics isn't the info im seeking. Im hoping to learn more about the principals of electrical equipment as they relate to batteries, current, amperage, resistance, ohms and the like. On my bench physics of a quadcopter has no bearing.

    I do appreciate your replies but have also discovered i may need to unsubscribe from this forum. The info i seek is more general and aimed towards improving my flying experience instead of using equipment and methods that %90 of people use. I like to improve and better myself and my toys. To keep a quadcopter the same as it rolled out the factory is not what i enjoy. If charging a battery, flying and then packing up til next time was my goal i could save a lot of money and fly my Syma X5SW everday. I never have to repair it. The cons are its slow, it is too easy to fly, the gyro fights me the whole time trying to stabalize the craft when i want agility, the range is poor. All these factors make FPV flying u eventful therefore pushing me towards the joys of hobby grade build, fly, improve, crash, repair, fly and repeat
     
  9. bjr981s
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    You obviously did not read what i wrote or did not understand it. I tried to keep your statement and show that it needed to be changed as per my additional comments. You r analogy was complexity wrong. I know being told you are wrong all the time is frustration .

    You have not been unable to understand and you have found this frustrating. I'm not the greatest teacher. As far as I know no more than you is also wrong my Degree in electronics would disagree.

    You are misinterpreting the basics of a power system that changes as the battery depletes. In your world that would would mean as you use gas the gas in the gas tank that is left over is no longer as effective and wont provide the same amount of energy and will continue to degrade.

    Hopefully one day you will get the basics and come back for further elaboration.

    If you just want to find people that agree with you there are plenty that will do that. But you will remain ignorant of reality.

    You can stay or go. Its your decision.

    You have a fixed opinion that you will not shake. Until you shake that you will not learn.


    This is far far from then truth. I have tried to find a way to get you to understand what you keep failing to see.
     
  10. PicklePilot
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    PicklePilot New Member

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    Lol, now you're just being common. I'm sure I'm not the only one who has told u these things, hense your attempt at degradation. Your electrical degree from 30plus years ago doesn't impress me just as my chemistry degree from 8yrs ago rarely impresses anyone. If we had expertise and demanding and worthy careers using these degrees we wouldn't have time to talk toys on an online forum daily, hahaha. You may have some knowledge but your common sense and social skills do nothing for the hobby as most of us only want to enjoy our toy copters, planes and cars and not use them as a means to demean others. You try to talk a good talk but I've yet to actually see any proof of your abilities in the quadcopter field (custom builds, unique mods, etc). I've actually mostly read repetitive statements and until last couple of replies i thought u could possibly be a rep replying from a script lol.
     

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