High Amp Master Switch

S

SarDoX

10 mW
Joined
Aug 22, 2015
Messages
33
Hi everyone!
I have some stupid questions - what type of switch is it better to use for high Amps? 80-100a (3kV)
I have 2*4s lipos, 30v total
motor max current can be under 100a
I need to install switch to turn on/off the scooter.. otherwise I have to unscrew board every time to plug connectors manually
I checked radioshack they have only 125v10a that is not enough

1a. what switches do u use?
1b. can I use something like 30 Amp 110v Single-Pole Circuit Breaker from homedepot? it should handle ~106A at 31V. And price is jsut 4$
2. is it safe to store scooter in garage with all connected wires but turned off master switch?
3a. topic unrelated question - I have a lipo low battery beeper and voltmeter for 8s battery, it has 9 wires - 1 ground and 8 for lipo cells
2 my batteries has 5 wires ea - ground and 4 for cells
can I use this beeper to controll voltage of all 8cells by connecting 2 grounds (from each battery) together and then all cells wires one by one?
3b. Can I use an extra switch to disconnect ground from this beeper to turn it off when scooter is turned off with a master switch? I dont need beeper working when scooter if OFF. Are these 8 cells pins with disconneted groun pin can drain lipo to 0 somehow?
 

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you Need small voltage, control of the Relais
(Maybe 12V out dc-dc Converter) and Switch on/off nice button
 
Thanks guys!
Wanted a more budget decision but looks like ssr / crydom is the only way to go...

what about other questions:


3a. I have a lipo low battery beeper/voltmeter for 8s battery, it has 9 wires - 1 ground and 8 for lipo cells
both my batteries have 5 wires ea - ground and 4 for cells
can I use this beeper to controll voltage of all 8cells by connecting 2 grounds (from each battery) together and then all cells wires one by one?
3b. Can I use an extra switch to disconnect ground from this beeper to turn it off when scooter is turned off with a master switch? I dont need beeper working when scooter if OFF. Are these 8 cells pins with disconneted groun pin can drain lipo to 0 somehow?
3c. how to connect brake button to VESC? should it be connected to PPM-signal 3 pins?
 
sansander.ebike said:
you Need small voltage, control of the Relais
(Maybe 12V out dc-dc Converter) and Switch on/off nice button
Click to expand...
I think I'll jsut use extra 9v crone battery for it
 
Hello

all those electronic switches are too expensive i think you should go with a xt-90 loop key it will cost you just U$ 4.50 and its better than anything, besides it will work as a key :mrgreen:

this is how you can do it,
https://endless-sphere.com/forums/viewtopic.php?f=35&t=72687&hilit=xt90

the bullet connector are not mandatory so just use the positive wire for the loop.
 
yes is expensive,
the same search I have also had.
you can also C63Breaker to install.

But so a relais is much nicer.......
 
Can anyone explain why 110v 50a circuit Breaker wont fit here? they are under 10$ and can handle 5kv
 
Hi
That Croydon SSR will dissipate a lot, and I mean a lot, of heat while 100A is flowing through it.
You would need a huge heat sink, without this the relay would destroy itself very quickly.
Please look on the data sheet, www.crydom.com, under the heading "Thermal derate".
Totally impractical for a E-skateboard I am afraid. On a scooter only if thou have space for a chunky heatsink, far bigger than the relay itself.

Cheers
WeeCh
 
WeeChumlee said:
Hi
That Croydon SSR will dissipate a lot, and I mean a lot, of heat while 100A is flowing through it.
You would need a huge heat sink, without this the relay would destroy itself very quickly.
Please look on the data sheet, http://www.crydom.com, under the heading "Thermal derate".
Totally impractical for a E-skateboard I am afraid. On a scooter only if thou have space for a chunky heatsink, far bigger than the relay itself.

Cheers
WeeCh
Click to expand...
what about this one?


I have a goped scooter project so i have a lot of space left under the deck
 

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Hi mate

The mechanical relays would work, there is just the problem of the initial spark on switch-on.
Relays are rated at max.breaking and making current. As you will not be switching your scooter off while bombing down the street that does not really apply On switch on there is also very little load. Unfortunately on switch on there is a high current spike while charging the caps on your ESC. This causes a spark which does erode your contacts over time. Let's face it though, you will not be switching your scooter on 100 times a day. So yes, it would work. (Sparking could, possibly, cause problems with the esc)
Really, the best you can do is get something like this:
http://diyelectricskateboard.com/product/on-off-high-voltage-anti-spark-power-switch-2-14s/http://
http://www.enertionboards.com/electric-skateboard-parts/high-amp-120A-electronic-ignition-on-off-switch/

My 2 cents anyway.

Cheers
WeeCh
 
Do not leave your longboard in a garage. First off if you live in canada like i do, the weather goes from hot to cold and cold to hot which can destroy your board. they will twist and not be usable. Maybe you can twist it back but its tough. It requires heat gun and lots of clamps. Best to leave it in a warm place
 
So.. I ended up with "custom" connector switch
switch.jpg
The only problem here that it sparks a bit when Im inserting "the key"
But.. since Im not usuing goped a lot - I think it wont make any problems
 
I just leave my batteries connected, and disconnect the logic circuits with a cheap on/off switch.
this means the caps are always charged, and there is a small power drain... but its so small that its almost identical to the batteries just sitting out.

since its lipo anyway, and a HUGE size, I would have to ignore the massive lipo sitting in the garage for well over year before I had a discharge problem.
 
MrDude_1 said:
I just leave my batteries connected, and disconnect the logic circuits with a cheap on/off switch.
this means the caps are always charged, and there is a small power drain... but its so small that its almost identical to the batteries just sitting out.
Click to expand...
I not understand what you mean. A switch between caps and ESC?

With a bms like this one http://de.aliexpress.com/item/36V-2...BMS-60A-continuous-120A-peak/32459655141.html, I have to install the switch before or after the BMS? Or is there a better way to switch the BMS on and off?
 
I think his ESC has option to turn on/off depending on voltage in some logic circuit. Like a signal wire in car audio..
So basically his ESC is always connected to battery but due to logic circuit in ESC it turns itself off
 
I saw some FET switches like this: http://diydrones.com/profiles/blog/...tId=705844:Comment:1725708&xg_source=activity. It's similar to Vedder anti spark, but a bit simpler. The only reason i prefer this, is the noob friendly circuit diagram. It would be awesome if someone could give me a beginner friendly circuit diagram to build a switch like these. But with some resistors/fuses/... even if I don't know what they are used for. I just know you didn't add them just for fun.
 
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