# Pixhawk power module for heavy lift drone

Hello,
i am building an hexacopter that should have a payload around 6kg.
i bought 6 eaglepower ea55 motors, and 2255 propellers, and i am going to buy a 6s 14000mah battery.
In this configuration, the motor draws a maximum current of 53A, and an average current of 27A, as you can see from ECALC:

The problem is that i thought to use PIXHAWK as flight controller, but in the kit that is commonly sold, the power module that feeds the flight controller with battery information, can measure 90A maximum draw.

I need a power module that can go way over this limit:
i found the attopilot 180 and other devices based on hall sensors to measure current, but they not go over 180-200A.
This is not enough , because i can have 53A*6 = 320A current draw max.

Do you know any solution to measure this high current?

I thought to buy 2 of the 180A max (hall)sensors, to divide the wire (+) coming from the battery in two almost identical wires , and to measure the current drawn fom each of these wires, ‘summing’ the results.

Do you think that this is possible?
If yes, how can i ‘sum’ the results?

The pixhawk current measure pin is driven by voltage, so i should sum the voltages measured and pass this information to the input pin.

I found these sensors, too:

https://www.mauch-electronic.com/apps/webstore/products?page=2

but again, they do not go over 200A

do you have any suggestion?

thank you!
Lodovico!

Given the high current draw of this aircraft - I would highly recommend using two batteries in parallel. Pulling such high amperage from a low C battery (15C) will result in a very high voltage sag and reduced performance. Two smaller batteries with a higher C rating (20C+ each) would result in much lower sag due to the power distribution. Also, this will allow you to use two current sensors (one on each battery connection) - allowing for measurements up to 400A (using the 200A modules you linked). MAUCH setup would be as follows:

Here are some batteries that could work (with two in parallel)…

FYI: I would also recommend just a bigger mAh capacity overall - since 14Ah will probably net you no more than 10 minutes of flight. Don’t know if this will be an issue for you - but having a bigger battery would probably help a lot.

Thank you very much,
now i check the price of this solution.
By the way, do you know a web shop to buy the Mauch components at cheap price?

I found this 0-400A amperometer at about 10USD:

But perhaps it requires input 15V , and output is in the range 0-4V, do you think it could be adapted to the pixhawk input current measure pin ? which is the voltage range required by this pin?

EDIT: SORRY, this is only a sensor, not an amperometer…

Thank you!

sorry, to be honest i don’t understand the datasheet of the component (hk16) that i posted above.
what is it? an amperometer or only a sensor with fixed output voltage when there is some current passing through the hole?
someone can help me to understand what is it?
thank you!