Lacking LiPo Ninja status

[Adrock]

I've read through the LiPo battery thread a few times and I feel like I'm missing something. I spent a few hours trying to fully grasp the idea on how to figure out which battery will work best for me. From what I gather, you always want to have enough continuous Amps running to your ESC's. I have (6) 40A ESC's on my Tarot T810 and I could be wrong but I thought you take the Amps required (40) and multiply that by the amount of ESC's on board (6)? If so, that tells me I need to 240 continuous Amps available at all times. The battery they sent me was a 9000 mAh 6s 25-50c. Again, I could be wrong, but doesn't this battery only offer 225 Continuous Amps?

A x C = Continuous Amps Available (9 x 25 = 225)

Maybe I don't fully understand what is required for the ESC's or what the C range of 25-50 really means. I also could totally be over thinking this whole thing ahahahah.

 

[econfly]

The 40A spec on your ESCs is a maximum rating. In reality you will be using well under that assuming the copter is built correctly. Your calculation for the battery is correct. What matters is the power you need to fly. Likely you only need somewhere in the neighborhood of 75 to 100 amps to hover, but that is just a wild guess. It depends on the total weight of your rig, the efficiency of the ESCs and motors, props, etc. One way to measure that is to charge the battery, fly for a set period of time (say, 5 minutes), then charge the battery again, noting how much power you put back into the battery. You can then convert to an average amp requirement to fly (with some error due to charging losses, of course).

 

[Adrock]

Thank you! One other question about connectors. I'm currently set up to accept XT60's. Is this anything I need to be overly concerned about?

 

[Bartman]

adrock, what Econfly said is correct. to really know if your batteries are appropriate for the application you have to look at what your motors are drawing in amps when hovering and when at max throttle.

trainer heli's will be flittering around at partial throttle, aerial imaging/media rigs will drone around at hover-power for long periods, FPV racers will often be zipping around at max throttle. knowing this helps you to better assess if your power needs can be met by your battery.

if your motors have a corresponding performance chart, look at it to determine what the amp/current draw will be at different power/prop/voltage conditions and then multiply THAT value by the number of motors. multiplying the ESC rating by the number of motors only tells you what you might need if you ever ran at the ESC's max limit.

 

[Bartman]

What's the max current through your connectors?

 

[econfly]

As the name implies, XT60 connectors are designed for sustained current of 60 amps. They can handle well more than that for brief periods of time. As Bart asks, the key thing to know is your max current demand during sustained flight. If it is over 60 amps you probably want a different connector. XT90s are nice, and there are a lot of other options out there as well.