Understanding C ratings of lipos


#1

I recently purchased a mantis85, I wanna order better batteries. But I’m not sure how to figure out the highest C rating the fc, esc and motors can handle.
Fc: f4 Processor: STM32F405RGT6 MCU
Sensor: SPI Sensor MPU6000
Built-in Betaflight OSD
Esc:Firmware version: BLHELI_S 16.5
BB2, 48MHZ Chip
Lipo Battery: 1-2S
Con. Current: 6A
Peak Current: 10A (5S)
Motors: Happymodel SE1102 KV9000
Or perhaps I’m worried about nothing idk!:smile:


#2

You’re worrying about nothing :wink:

The C rating is the amount of Ampere the battery can supply to your quad. It doesn’t just pump it all into your hardware though, the quad will only draw what it needs.

The only thing you need to worry about is the amount of cells and, respectively, the voltage of your battery. Too low and your quad has no power, too high and it will go up in smoke.


#3

Bigger props, higher Kv motors, and higher number of cells in a lipo increase the current the motors will draw.

C rating is how fast (theoretically) the lipo can give current. Check this out for a great explanation: https://oscarliang.com/lipo-battery-c-rating/

Basically what you want to be sure of is that your motors don’t draw too much current and overheat or fry your ESC. And to make sure of that balance the above.


#4

Also, don’t forget that if your battery can’t provide sufficient amps then you can damage the battery through heat as it struggles to keep up with demands and you get puffy batteries with less capacity and performance.

I always used to ignore C rating but there is definitely an improvement of performance when finding batteries that suit the amp draw of the quad.


#5

Thank you gentlemen. I had not searched Oscars page for info.
@yets i thought the e011 was solid and strong with the stock 30c bat. But when the 45c bats showed up I decided the stock bat. Is good for warm up. You can feel the stock bat sagging almost immediately, compared to the 45c bats. Espescially the first few minutes


#6

I’m the same with my E011, even at 30c the sag is bad but bear in mind take c ratings with a pinch of salt, especially with cheap batteries. I think a true 30c battery would be fine on E011, I don’t see 716 motors taking more than 2amps each.

Just taking a punt, I’d say you’d probably want 40c minimum for the mantis85 if using that capacity. I’ve not seen any thrust tests for for those motors on 1935 Tri but I would guess they’d max at around 4amp each on a bench. Probably never going to reach that in flight but I always calculate for. 16amp divided by capacity would get you 40c in my probably wrong calculations. I may be totally incorrect but that’s how I choose my batts.

Check out a few YT videos of the Mantis and see the sag on the OSD.


#7

I ordered a 5 pack of 45c 260mah eachine lipos for e011. Cant complain. Although 1 does seem to be stronger. It will make the motors squeek a lil. Switch to another lipo and no squeek. Put thAt lipo back in and squeek city. I was thinking the eachine 450mah 80c. But I’m just starting out in this. Any recommendation on battery companies in general is welcomed.
I used a lot of turnigy lipo on my ground rc’s.
But eachine seems to make decent products at a nominal cost.


#8

Just did a bit more research on the Mantis and general consensus is the stock battery let’s it down. Honestly, like it has been said, at the moment I wouldn’t worry about it as you’re starting out. Unless your battery is coming down super warm that is…

Imo, GNB are good for the price and they have a range of capacities. I use batteries from hobbyking too (turnigy and Nano-techs), decent performance for decent price.

Eachine make a good 2s battery for the Aurora 100 but when you start getting amp hungry motors you’ll be able to see the difference in quality