What is the minimum and/or recommended discharge rate for 500L battery?

[kirby_]

I'm trying to figure out the minimum discharge rate for an upcoming TREX 500L build.

I saw one store throwing in a 2600mAH 40C battery for free, that works out to 104A. Which would be about 35C for 3000mAH and 32C for 3300maH. But, the stock ESC is rated at 70A continuous with 110A burst. So is this oversized? I'm looking mostly at 3300mAH batteries and I notice several major brands have 3300mAh 30C, can I use those?

What do you all think?

[Digger1973]

I use 6 cell 3300mah 30 packs in my 500pro running 3100hs. They work fine. Check your motors continuous current. If the packs meet that then they should be able to handle a 2 sec burst at max burst rating. For my 550 my motor is rated at 100 with a burst of 110. I use the same packs in that as my 500pro

[Gladius]

A lot of it depends on how you fly. If you're running a medium headspeed while doing a lot of sport type flying. Then 30C should work just fine for you. I personally like 45C, because it gives me the option to run the heli as hard as I can. I also use the same packs in my 600, and full collective pitch pumps will really pull some amps.

[kirby_]

Ok, I'm confused by a couple of things:
Digger: You said 3300mAh 30C packs are ok for a motor that is spec'd at 100A continuous? That seems like you're cutting it close, Isn't the max output of that pack 99A?

Also, on the 500L, here are the limits:
- Motor is 500MX,
Amp limits is 75A continuous, 100A burst. But, watt limit is 1600W continuous with 2300W burst. Since I'm running 6S, At 3.8V per cell (worst case)That turns into ~71A continuous and ~101A burst.

- The ESC is RCE-BL70G, 70A continuous, 110A burst. This makes more sense when considering the watt limits of the motor.

So it looks like a 6S that can output >90-100A will fine. But, I might want more margin if I want to reuse the batteries in a 600. Did I do that right?

[Gladius]

looks pretty good to me!

[Digger1973]

Kirby. I have been flying these packs for two years without issue . I run the same motor and align esc. I push my 500 hard and these packs have never let me down. If your able to push the peak then wow your really pushing it. On my 550 i also run the packs as 12cell which drops the amp draw while increasing voltage. 4 packs have over 150 charges on them and the other 3 have around 90 charges. All i can tell you is they work great in my 500pro and synergy e5.

Also a 3300 35c rated battery should work out higher than 99 amps. 3.3 amps X 35c would be 115.5 amps not 99. Plenty of overhead.

[Xrayted]

Originally Posted by kirby_

Ok, I'm confused by a couple of things:
Digger: You said 3300mAh 30C packs are ok for a motor that is spec'd at 100A continuous? That seems like you're cutting it close, Isn't the max output of that pack 99A?

Also, on the 500L, here are the limits:
- Motor is 500MX,
Amp limits is 75A continuous, 100A burst. But, watt limit is 1600W continuous with 2300W burst. Since I'm running 6S, At 3.8V per cell (worst case)That turns into ~71A continuous and ~101A burst.

- The ESC is RCE-BL70G, 70A continuous, 110A burst. This makes more sense when considering the watt limits of the motor.

So it looks like a 6S that can output >90-100A will fine. But, I might want more margin if I want to reuse the batteries in a 600. Did I do that right?

Your electronics will only pull the current they need for the way you fly. The max rating on the battery and electronics are just that........max ratings they can sustain which does not mean you will actually get anywhere near those values.

For example, lets say you average current used for you flights on your 500 is 30A. It doesn't matter what your C rating is, the heli will still only pull 30A. You could have a 100C rated pack capable of possibly providing 330A if the electronics or flights style needed it, but your heli will still only pull the same 30A. Batteries do not "force" current into your heli. They only provide what your electronics draw out.

The same applies to motor and ESC Max ratings. My 700s motor is rated for over 11,000 watts. My flight style, even doing hard full pitch speed runs has never pushed it beyond half of the rating no matter how hard I try. My 4500 packs are 65C rated, so 292A yet I run a 160A ESC because I know my flight style will never get anywhere close to pulling more than 160A for sustained amounts of time. Sport flying on my 700 is in the 50-90A range all day long.

Your car may have a 300HP motor, but that doesn't mean you are driving around with it maxed out using all those 300 HP every time you drive. It's just a max value it can provide if you were to ask for it, and it's the same with our helis

[Smoggie]

Yes, what Xrayted said.. Plus of course LiPos also have a 'short burst' rating which is usually around 1.5x the constant c rating.

To counter that the c rating on the label needs to be taken with a huge pinch of salt, manufacturers grossly exaggerated, especially at the higher c ratings.

I found with my 500 that 'the higher C rating the better'. It also depends a lot on brand because some are more truthful in their rating than others.

[Alzrc devil]

Y used 2700 MHa for 3:45 time fly

[caracola]

Originally Posted by Alzrc devil

Y used 2700 MHa for 3:45 time fly

+1
Y used 2700 mha and Pinnion de 13t,,,very power in time 3.40 time

[Excalibur3]

Stock set up style 3d
Pulse 6s 2600 45c & align 6s 2600 50c for 3 minutes and they come down at 3.83 per cell. I feel these smaller packs are better to reduce the weight down.

Trex700Pro/Trex700LTop/Trex500L/14sgh T$3D

[caracola]

Originally Posted by Excalibur3

Stock set up style 3d
Pulse 6s 2600 45c & align 6s 2600 50c for 3 minutes and they come down at 3.83 per cell. I feel these smaller packs are better to reduce the weight down.

Trex700Pro/Trex700LTop/Trex500L/14sgh T$3D

Cap One video the helicopter for see!!!!

[Mateyhv]

Originally Posted by Excalibur3

Stock set up style 3d
Pulse 6s 2600 45c & align 6s 2600 50c for 3 minutes and they come down at 3.83 per cell. I feel these smaller packs are better to reduce the weight down.

Yes, lighter is better for 3D. In the old days Jason Krause used 5s 2200mAh batteries for his Trex 500!

[Excalibur3]

I would love too but my camera man was the worst ever and had the shakes. Useless video. I'll make a new one soon
If you want to brave a head ache here it is

Trex 500L flight 2 Art Ts3d (3 min 24 sec)

Trex700Pro/Trex700LTop/Trex500L/14sgh T$3D