switching of main lipo battery

[Basil]

Hi, I am a novice, hence this question. I have a plane that is an IC to electric convertion. The only way to gain access to the Lipo power sauce once ready for or finished flying is to take off the wings, via elastic bands , and eveyrthing that this entails.

Is there a simple way to provide a way of turning the main lipo supply on/off..

An ordinary in line switch would require something quite heavy to cope with the amps involved. A gadget that requires an inserted plug/key from the outside seems most feasable, but I cant find one, as yet.

Has any body have any suggestions. I dont want to go down the road of seperate lv swiotch for the RX, because of the added wieght of say 4xcells, and the problems this would cause, in this case, with the CG etc.

I look forward to your replies, as it is obviously a simple answer.!!!!!

Barry

[kc]

Several ways to do this

I cut a small hatch on top to enable the Lipo to be plugged into the ESC

2. Study this conversion of the WOT4 to see if it can be applied to your model. This is a hatch underneath with the Lipo strapped to a ply plate which is inserted and then held with a wing bolt etc.

3 Cut a hatch in the top of the model to change the Lipo and also connect up when ready to fly.

Edited By kc on 09/09/2020 15:33:59

[kc]

I think it's safe to say that virtually nobody uses a switch in the Lipo to ESC connection.   Everybody that I know plugs in the Lipo to ESC through the XT60 or similar plugs.   ( many Lipos come with XT60 plugs already soldered on which is handy. )     Some people use a 'shorting plug' instead of a switch.   This is usually on the outside of the model.

Edited By kc on 09/09/2020 15:31:08

Edited By kc on 09/09/2020 15:35:52

[John Lee]

You can buy a commercial arming plug, such as Link Search 'R/C Arming switch' or 'R/C Arming switch' for alternatives.

Another option is to extend one of the leads between the connector & ESC, take it outside the fuselage and insert a bullet connector. Here's one of mine:

[Denis Watkins]

Arming plug on the outside

**LINK**

Edited By Denis Watkins on 09/09/2020 15:53:34

[Colin Carpenter]

Have a look at HK XT60 panel connector kit. I use them a lot 👍Colin

[Ron Gray]

4-Max have both plugs and harnesses.

[kc]

The link to 4 Max shows the plug and a harness for XT60 to connect 2 Lipos in series - is this harness the one to use in a 'shorting plug' setup too? ( logically it seems to be the thing to use but it doesn't say so! )

[kc]

The photo shown by Denis looks better as it seems to use a different style of plug for shorting. It seems to me to be bad practice to use a shorting plug that could be accidently pushed onto a lipo and short it out.

[Phil Green]

Its a simple project to make a high-current switch using a hyperfet, these will pass hundreds of amps continuously with a resistance of 2 or 3 milliohms. The physical switch itself can be a lightweight toggle or slide switch as it carries almost no current, the hyperfet does all the work

360A Hyperfet

Cheers

Phil

[Dale Bradly]

Phil can you post an appropriate circuit diagram of that hyperfet switch pls?

[Basil]

Thank you all for your input I will be going over your info to make a decision Barry

[Bruce Collinson]

Phil,

If £15 buys a component which can switch hundreds of amps, can be controlled from a simple small low current switch and presumably is small and light enough for a model, then it begs two obvious questions to me:

• firstly, why has nobody gone into production with a model-ready setup
• secondly, this topic has been aired repeatedly here and I'm certan in pit lanes across the world where all electric modellers have the identical dilemma, i.e. when to arm the plane and how to be safe after you have done so. Why did no-one mention this device?

As a returnee with mainly leccy upto 6S I would pay quite well for a robust ready-to-fit set with say choice of XT 60 or 90 as it would provide exactly what I would like, ability to disconnect flight batteries via an external switch. It could have bare wires as even I can solder XTs.

George Worley, you reading this?

BTC

[Dickw]

Posted by Bruce Collinson on 10/09/2020 13:52:09:

Phil,

If £15 buys a component which can switch hundreds of amps, can be controlled from a simple small low current switch and presumably is small and light enough for a model, then it begs two obvious questions to me:

• firstly, why has nobody gone into production with a model-ready setup
• secondly, this topic has been aired repeatedly here and I'm certan in pit lanes across the world where all electric modellers have the identical dilemma, i.e. when to arm the plane and how to be safe after you have done so. Why did no-one mention this device?

As a returnee with mainly leccy upto 6S I would pay quite well for a robust ready-to-fit set with say choice of XT 60 or 90 as it would provide exactly what I would like, ability to disconnect flight batteries via an external switch. It could have bare wires as even I can solder XTs.

George Worley, you reading this?

BTC

Electronic switches have been around for some time, but have generally been large and expensive (they also do a 200A version) - (and other brands are available!).

A lot of people would be interested in a smaller, lighter, cheaper version.

Dick

Edited By Dickw on 10/09/2020 15:03:06

[Frank Skilbeck]

Multiplex have done their Antiflash 70 for ages and this can be fitted with an arming switch, I've never seen one in use though.

Also, you don't see them much these days, but you used to be able to get ESCs with an arming switch, I know I've got a couple of Jeti units that have this feature but they are quite old now.

Edited By Frank Skilbeck on 10/09/2020 15:08:34

[Basil]

The Hyprafet seems a good idea but surely dont you need another power source in addition to the Lipo to power it?? It is the additional batteries that I am trying to get rid off, or have I got it wrong.

Barry

[Former Member]

[This posting has been removed]

[MattyB]

Posted by Steve J on 10/09/2020 15:26:07:

At the end of the day, how is having a one of these FETs controlled either by a switch on the model or a switch on the transmitter functionally different to having a switch on the transmitter that sets the throttle output to 0%? All these solutions rely on the pilot flicking a switch.

I agree. Everyone is different, but personally I am happy to rely on a software only solution - most TXs now have the capability to setup a “2-factor” sticky throttle cut (I.e throttle is only enabled when switch is on AND throttle stick at the bottom) which is very safe. OpenTX and some other systems can go even further requiring multi switch combinations/sequences etc for arming. Some will argue a hardware based solution is safer than a software one, but I’m yet to see a TX suddenly reconfigure itself between flights but I’ve observed plenty of additional snafus associated with physical arming systems.

Edited By MattyB on 10/09/2020 15:55:57

[Former Member]

[This posting has been removed]

[Bob Cotsford]

Posted by kc on 09/09/2020 16:46:22:

The link to 4 Max shows the plug and a harness for XT60 to connect 2 Lipos in series - is this harness the one to use in a 'shorting plug' setup too? ( logically it seems to be the thing to use but it doesn't say so! )

kc,the external shorting plug has two female esc type connectors and one male for the battery, one female is used for the external socket to accept a shorting plug and the other for the esc connection. The serial connection Y leads have two male to connect to batteries and one female for the esc connection. The external shorting plugs are further down the page!

[Phil Green]

Posted by Bruce Collinson on 10/09/2020 13:52:09:

Phil,

If £15 buys a component which can switch hundreds of amps, can be controlled from a simple small low current switch and presumably is small and light enough for a model, then it begs two obvious questions to me:

• firstly, why has nobody gone into production with a model-ready setup
• secondly, this topic has been aired repeatedly here and I'm certan in pit lanes across the world where all electric modellers have the identical dilemma, i.e. when to arm the plane and how to be safe after you have done so. Why did no-one mention this device?

Fair cop Bruce I must be making this up.

 │ Posted by Basil on 10/09/2020 15:21:57: 
 │ ..., or have I got it wrong.

You have 

 

 

Edited By Phil Green on 10/09/2020 23:19:17

[Basil]

Phil,how do you power the component then through the main Lipo. I have only the Lipo to power the motor and RX as is usuall. The wiring diagram that I have seen shows a seperate Lt bat running the RX that then switches the main FRET.

Yes, just looked again. Both diagrams show the RX is powered by a seperate battery!!!

Barry

Edited By Basil on 11/09/2020 09:45:52

[Bruce Collinson]

Ouch.,

[Phil Green]

Posted by Bruce Collinson on 11/09/2020 13:47:42:

Ouch.,

You were the one casting doubts on the suggestion Bruce, and at some length too

Dennis has documented one, over on RCG: FET lipo switch , its a totally conventional low-side FET switch but he's drawn nice diagrams & everything, - FET between lipo neg and the ESC neg, lipo pos to ESC pos, switched lipo V on the gate. He's put a 12v limit on the gate for larger lipos. By changing the gate bias resistors & switch around you can have contact-ON or contact-OFF switching, which ever you feel is safest. Ignore the tangent about BECs, just connect the ESC to the rx as you would normally

 

 

Edited By Phil Green on 11/09/2020 14:21:00

[Former Member]

[This posting has been removed]