Power cut off switch


#1

Found this switch on amazon which might work. Good for 60v and 500 amps. Looks industrial quality. Could probably dril hole in the handle for installing cable to pull the disconnect if needed in flight.

https://www.amazon.ca/Sedeta-Battery-Disconnect-Isolation-Commercial/dp/B074M6FZ4R/ref=pd_sbs_263_15?_encoding=UTF8&pd_rd_i=B074M6FZ4R&pd_rd_r=b5d0d70b-e200-11e8-abc2-2bf33ae66452&pd_rd_w=PV4Yt&pd_rd_wg=uIMwL&pf_rd_i=desktop-dp-sims&pf_rd_m=A3DWYIK6Y9EEQB&pf_rd_p=d4c8ffae-b082-4374-b96d-0608daba52bb&pf_rd_r=QMQAN3AA65YJBFVFJDJA&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&psc=1&refRID=QMQAN3AA65YJBFVFJDJA


#2

My team is working on a commercial Li-Ion batter for this product now, and we can simply put a ON/OFF switch built into the battery BMS for you guys. This way, battery wires are always dead until you flip the power switch on the battery. Fewer wires and connections to deal with!

Simply connect battery, turn on and fly!


Important! Wire sizing for current draw
#3

Hello Chris (@VeConcepts),
I noticed in the other thread, that you’ll eventually convert from a surfer to a paramotor pilot :slight_smile:

what’s your commercial battery going to be? Lithium Ion? Lithium Polymer Pouch Cells?

Most, if not all Pilots who have received their batch 1 and 2 OpenPPG kits have gone the Lithium Polymer Pouch Cells route, I am one of the few who decided to go the 18650 Li-Ion route.
Have you noticed my build thread?
I am close to completion: 13S15P Battery Pack Build

Just curious!


#4

Very nice looking pack!
I am a pilot already having been a certified pilot at the age of 16 before I could legally drive a car :slight_smile:

Lipo/pouches I will not do. High quality lipo cost nearly the same at Li-Ion with BMS and they last 600+ charges… Lipo cost way more in the long run and are deadly when pushing limits and high currents like this.


#5

Pouch cell are not exclusive to lipo chemistry, think of your cell phone, newer laptops etc… one isn’t inherently safer over the other, it’s more about how they are managed (BMS, charging, discharging, temp) I think the main reason LiPos seem to get a dangerous label is because they are selected to be used in more demanding environments because of their ability to discharge their energy quicker than Li-Ion. Even saying that sentence sounds funny because we could really be talking about what the anode and cathode are, being they are far more important to understanding the cell chemistry and properties. Lipo and Li-Ion are sort of like blanket terms and there is a lot of gray space.

As for cycles again it’s how they are treated, lipos are generally put in higher discharge environments so they tend to suffer and most drone enthusiast don’t use any BMS with lipos so they are not managed as well, and say 18650 aren’t used because they can’t with there historic lower amp rating (its super confusing because now many of the 18650 in the 15A and above rating use polymer chemistry (lipo) Well actually 99% of 18650 contain polymer. I think when most people refer to Lipos they are just referring to the pouch/flexible cells (also where the polymer term comes from). That’s where people see the puffing from Lipos because they are flexible, vs steel cased cells (18650) can’t puff instead they build up pressure and either set there CID off or vent gas. 18650 do have a metal case around them so they are a bit more protected by nature it not really the chemistry.

Again its all about the way you treat and manage them. You can have li-lon “explode” https://youtu.be/WdDi1haA71Q?t=408 its all about management, in this example these guys were idiots and charged them wrong. Management management management - I think you guys get the point.