The other way around


#41

Weight is 5086 grams.


#42

Thats great. Not long ago i was looking at 15-16 20Ah lifepo4 pouch cells, i had a good deal on them. With around 315g each, thats about same weight as yours at half the capacity. Price for new was not much under 400€ if i recall well.


#43

The good thing about these cells is that they are rated for automotive use. We will never find that quality in rc cells.


#44

Update! The 100kv Alien is now ”shrink to fit” mounted in the all tube. Sits firmly. I added x layers of alu tape to the motor to get a dia that’s slightly larger than inner dia of tube. Then add fire to tube :slight_smile:


#45

First spin!


#46

Hi, Riwi put it in the water and you will see there is not enough torque. Also the max Amps I can achieve is around 15 Amps. I have 2 motors like this( Aps 56115 100kv from Freerchobbies-Mark Tan is the seller) and I tried them with 14S and 22S Liion battery. The Esc is Flier up to 22S 400A.
Please report if your motor works different.


#47

Hi!

What happens after you reach 15A?

What prop diameter and pitch do you use? Any pictures?

I will report as soon as I hit the water.

Br Rikard


#48

The propeller stops. I can quite easily hold propeler with my hand. The proppeler is 4 blades prop from Pacificmeister and I tried also others.
I thought the problem is in Esc but I’ve realized there is a motor problem. I bought Sss motor 56114 360kv, there is no way I can hold the shaft with my hand. Also the current flow on sss motor bursts up to 30A for a second and then I cant hold it anymore. My next step is to measure exact max Rpm and torque of the motors and then I will decide for planetary gear ratio, because I am planning to use 22S battery. I build the hole hydrofoil on my own, and I had a plan of using direct drive, but I didnt manage to suceed.
I’ve posted some pictures few months ago, Rikard please check my previous posts if you are interested.


#49

Battery update. Did a stress test of the batteries today. Got a 2,5kw pure sine inverter for 48V. Hooked up my heat gun and the vacuum cleaner. Maxed out on 2000W while monitoring the temperature with my FLIR. Excellent setup :slight_smile: wife loves it to since the apartment gets warm and clean.

These cells are amazing, VERY stable temperature. I pushed 50A out of a 42,5ah pack.

Cables reach approx 30 degrees Celsius. Might do an upgrade to 8awg.


#50

30 degrees on 10AWG? Wonder what they will get up to with at around 80A…


#51

Yes, guess that’s why people are seeing melted connectors. The FLIR is a good tool.


#52

I noticed that my connectors get hot, but the wire is not nearly as hot. Never really bothered measuring it though. I have moved to crimping more now though so as to avoid any solder melting and shorting…
I’m also going to install a few temperature sensors to shut things down if they get too hot.


#53

What connectors do you use? I use the xt150 and noticed that it needs some adjusting after a while to get max conductivity. The connector should feel really tight when connected/removed.


#54

For testing up to 5 minutes, I was just using 4mm bullet connectors and HST connectors. For my large battery I have crimp connectors that bolt onto the busbars and then I will most likely use either Amass XT150 antispark or the amphenol surlok. I know that fliteboard is using the amphenol surlok on their battery (https://scontent-lht6-1.cdninstagram.com/vp/33089db0391141462dee202d2f3ef05f/5CA60F68/t51.2885-15/e35/47055064_304178550207197_6819454063617245184_n.jpg)


#55

exactly, i add this problem with my xt150 from hobbyking (see my post), plug unpluged, not adjusting: connector soldered under high amp on the last ride (last a couple months …)


#56

i try to understand: room 20°C cables 30°C so +10°C for 50A that is not bad no ?
can you do the same with the cables twisted on each other (suppose to lower induction) ?


#57

If it’s stays on 30-40 I guess I’m good. I need a new charger before I can run a longer test. The plan is to run through 80% of the capacity and measure temp during the test.