Question regarding switches

Ive noticed that in all the pictures of people’s wiring the jumper that connects the two switches is connected to the same terminal as the esc’s shouldn’t it be connected to the other terminal that leads to the batteries? Does the arcing only occur at high power settings with the throttle pressed far down, bringing the load close to 300 amps? I thought that the arcing occurred during turning on the switch. And with it this way I see that all the esc’s are powered on using one switch (whichever is powered on first.)

Can’t answer your first question…The arcing will happen definitely at power up, as the capacitors from the ESC’s are getting charged and sucking a big amp draw. Only help would
be a pre charge, like a few owners have already

or these connectors with 5.1 ohm resistor - you connect them only 1/3 for a view seconds to load the
capacitors and then connect them fully… no arcing!

Personally I would not use the switches and would prefer a safety cut off with some kind of precharge…

Sweet that makes perfect sense thank you both so very much.

We use two switches to split the amps in half at each switch to reduce the chance of failure.

The arching occurs inside the switch as you turn on the switch if you don’t precharge the capacitors first. The arching damages the contacts inside the switch leading to switch failure. So a precharge is highly recommended.

If you do what you are suggesting and one switch was to go bad during flight then you would have only two motors running on the same side and that could potentially twist you around.

I like these connectors. I’ll get some.

Those connectors will prevent arching inside the connector if you don’t use a switch. If you use a switch with those connectors you will need to turn on the switch before plugging in the connectors to take advantage of the anti spark feature. That would allow you to turn off the machine using a switch but turning it on with the switch would still create arching inside the switch.

Basically, the connection that you use to close the circuit needs a resistor across THAT connection as that connection is made.

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Roger that. I got it clearly now. Thanks for your input fellas I truly appreciate it.

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You are correct here! Also, I believe @E-pusher wired his like you are saying. Mine is a combination of the two now after I converted to an optional 6 pack wiring setup but I didn’t realize it till I saw E-pushers post earlier today.

I believe this is the best option. If you turn on one switch then all batteries will run all ESCs through one switch. If you turn on both switches then the load through each switch is cut in half. If you fry one switch during flight you probably wouldn’t even notice (that’s a negative) but at least you still have all four motors running from all batteries.

If you fry one switch during flight, you will notice because of your short flight. Then you land with an empty and a full set of batteries (the full behind the fried switch). Then, cautious about what happened, you start fumbling with your switches. I don’t know how permanently dead a fried switch is, but if it picks up contact because of the fumbling, you get a full and empty pack in parallel. Might be that your switch then fries for final, or not and your lipos start cooking…. I stay with 2 motors per battery pack.

With the wiring method discussed in this thread:

So if a switch gets fried then all power from all batteries still goes through one switch.

Here’s a picture. It has inputs for two more packs at the bottom. I crossed out a redundant wire that I will remove:

Edit: that wire is not redundant. It needs to be there so that all four ESCs will run even if one switch goes bad.

Sorry I misunderstood. So I now see in your picture that all minus is connected together, where the T-cable of the third battery set connects the two minus star points. The plusses of the upper and middle battery set are each connected to a switch, but the T-cable of the third battery set connects the two switches, so all battery plusses are connected. Each switch feeds the two ESCs on that side. Not four ESCs anymore, since you removed the redundant cable that connects the two plus star points. So if a switch fries now, the motors on that side will stop (and maybe your controller, depending on to which switch it is connected…

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Yes, you are correct. However, I don’t want to remove that other wire because I don’t want only two motors to spin if a switch goes bad. So really that wire isn’t redundant.

The good thing about this setup is it prevents this:

All positive and negative battery wires are always connected regardless of switch position or condition. That’s a good thing during flight. Extra caution needs to be taken before flight to make sure a full and low pack are not connected in parallel. Then during flight I will have a monitor on every cell which my son and I are in the process of developing.

With your idea you won’t ever have a parallel connection but I think that with a good battery monitor it won’t be a problem.

I have a pre-built batch 3 unit. Is there any order when connecting the batteries to the frame? And when it comes to connecting the two plugs?

I’m not positive about how the wiring is done in the prebuilt. Can you send a picture from the back.

As long as you plug in everything correctly the order that you plug them in won’t matter.

found the following switch which is higher rated… any comments on suitability appreciated. The included switch I see also on eBay and for this 300 amp is usually specified as a momentary rating, much less than 300 for continuous.

Image 17-05-2020 at 11.44 (1)

the included switch in the kit…

Image 17-05-2020 at 11.58

I’ve just discovered this marine switch is quite heavy: 225g compared with the kit included switch is 50g.

Those marine switches are indestructible though.