S800, total weight 7kg, should I still use maxamps?

[saidquad]

After adding some extra equipment to my S800, The total weight is 7kg now which is the specified limit for S800. Until now the total weight was about 6kg and I had no issue using maxamps 11000mah 6s lipo. Now that the weight is 7 kg I don't know if I should fly it. I know that the real rating of maxamps is 5. Would this lipo still handle the weight of the 7kg S800? Does the C rating have anything to do with the weight of the bird?
My setup: S800 frame+ retractable landing gear +WKM+ IOSD+ DJI Video link for the nex7 camera + immersionrc 600mw VTX for fpv camera. Flycamone as fpv camera + Nex7 (incl. pancake Lens ) as the main camera + all wirenings and a one maxamps 6s 11000mah powering everything =>Total weight: 7kg

 

[DennyR]

I have been using the 1100 maxamps on my helis but I changed to the nano tech 6,000 mah and found that the endurance was only marginally longer due to the lighter weight of the batteries. But I'm using two of them to make 12s. They are a lot cheaper for a start.

When I was running S800 I found the maxamps to be good but I never tried the nano's. If you are up to 7 kilos I would use the 6,000 nano's. There is a definite cross over where more becomes less.

 

[saidquad]

I prefer to use my maxamps since I already have three of them. 11000mah 5c maxamps would provide 55
amps at most. I don’t know if 7kg S800 would draw more current than 55amps.

 

[JoshMaxAmps]

I prefer to use my maxamps since I already have three of them. 11000mah 5c maxamps would provide 55
amps at most. I don’t know if 7kg S800 would draw more current than 55amps.

Any idea on average amp draw of the setup before adding the additional weight? This is a heavier setup and normally in this situation we would recommend going to a higher C rated pack to eliminate any issues. The pack you have may be capable of handling this load but overtime it will deteriorate faster than a pack that can handle the load without issue. Our 9000mah or 10900mah packs that preform at a higher constant draw would be preferred.


Josh

 

[saidquad]

Josh, thank you for your advice. Unfortunately I did not pay attention to the amp draw before adding the extra weight but the lipo was handling the 6kg weight quit well. I guess the first thing I should do is to fly it any ways and keep an eye on the amp draw. Do you think if the amp draw is around 50 amps it is OK to use the packs that I already have without worrying about faster deterioration? Ordering new packs from US costs me about 23% extra for customs.

 

[JoshMaxAmps]

With an amp draw of 50 amps you should be just fine. I would test initially by flying near yourself and bringing down periodically to test the temperature on the packs. If your temperatures reach or go above 120 degrees Fahrenheit changes definitely have to be made.

 

[saidquad]

I will test fly it this weekend (if the weather is good) and I will post the results. I hope the amp draw stays bellow 50.

 

[saidquad]

Today I realized that I can’t measure the current while flying. I don’t have a current sensor. So I should just hope that the current consumption stays bellow 50amps. Anyone flying 7kg S800 powered by MAXAMPS 6S 11000mah? Any advice is appreciated.

 

[saidquad]

Today I did test fly the setup. I did fly about 8 minutes with each maxamps lipo (mainly hovering). I just checked the temperature of each lipo after landing and it felt like 40 to 50 degrees Celsius (about 120 Farenheit). Before this experiment the total resistance of each lipo was 27mΩ, but after this experiment the resistance is increased to 33mΩ. So I guess the fast deterioration has already begun. But what I was much more shocked about was how unstable S800 was with 7kg weight. With 7 satellites locked in ATT GPS mode it was difficult to control the aircraft and Z15 did shake very much. Also sudden descents happened many times. I guess before upgrading batteries new IMU and new vibration kit and God knows what other stuff are required.

 

[JoshMaxAmps]

Well when you are ready just give us a call and I will see about getting you our 10900mah packs which should hold up much better.

 

[ATFlyer]

I think you are maybe confusing the battery rating.
I think that the 5C you are referring to is the maximum CHARGE rate, not the discharge rate. I have googled the Maxamps 6S 11000mah and the discharge rate is quoted as 40C. This is the figure that you use when you calculate the capacity.

Therefore (assuming they are 40C) that would give you 440 amps. (11,000 mAH X 40C). Loads for 7kg.

 

[mitsaras]

I fly a similar configuration S800+Zenmuse+NEX 5R+retracts with the 10000mAh GensAce. Current draw hardly ever exceeds 45~47 amps.

 

[saidquad]

ATFlyer, I did have the same assumption as you before I did order maxamps 11000mah packs. But afterwards I learned that maxamps refers to true 40C rating on the packs as the peak, and not continuous draw. Continuous discharge rate of these packs are actually 5C.

 

[saidquad]

Mitsaras, what is the total weight of your setup? Mine is 7kg. I guess mine draws more than 47amps since the packs got warm during flight and the resistance of the packs has increased after flight.

 

[mitsaras]

I haven't weighed it, but it must be similar, I also have 600mW Immersion tx, and Graupner telemetry instead of iOsd. Lipos are warm to the touch after flight, I'd say maybe 40 deg C. GensAce packs have IR of less than 2mOhm/cell, only ~12 flights yet!

 

[saidquad]

2Ω/cell is very impressive. I do not fly more with my packs because the IR increased about 1ohm/cell after 8 minutes fly and that was only take off and hovering about 2 meters above the ground.
By the way I read on the GensAce site that the Max Continuous Discharge for 10amps GensAce packs is 25C (250A) and the max Burst Discharge is 50C (500A). So they are very much overqualified to be compared with my packs when it comes to C rating.

 

[tuxn]

I use the maxamp 11000 6S aswell on a simular setup. I have also 2 6S Nano tech and one 8000 6S nano tech.

When I fly the maxamp. I only get 5500mah when 3,5volts kick in.
On my nano tech 8000mah I get nerly 7500mah when 3,5volts kick in.

I have not looked on the resistens, but I will do lator today.

 

[flyingbiscuit]

I am flying the 11000 max amps as well, yes it's at the limit I get a lot of battery warnings when I climb , the batteries can barely handle the lift at close to 7Kgs. Can max amps let me know what I should do with the $1200 worth of batteries I have, that were never labelled 5C

 

[PeterLester]

You can pull 2G or more during initial acceleration for climbing which means your MR weight doubles.
It's much worse though when you try to recover from a fast decents as you can pull 3G or more in an attempt to recover from the fall......
Hence current draw increase exponentially in line with G force!!!!

I am flying the 11000 max amps as well, yes it's at the limit I get a lot of battery warnings when I climb , the batteries can barely handle the lift at close to 7Kgs. Can max amps let me know what I should do with the $1200 worth of batteries I have, that were never labelled 5C

 

[flyingbiscuit]

I am beginning to think the Max Amps may be a big problem with my machine, I would have never gotten into them if I had known there constant C rating, they wre extremely expensive batteries, not sure what I can do about it now.