Electric Bike - 48v switch, relay, contactor?

[NemoTheClown]

Hello,

 

I recently made my bike into an electric bike, and I've stumpled upon a little issue I might need some help with

 

The battery I've mounted is an 48V 20AH Cell Li-ion battery. The problem is that I don't have or seem to be able to find any 48v switch that can do the job, because of the current switch power.

Obviously I don't want anything to drain the battery, so I primarily want to switch the battery off without having to open the bag and disconnect the wires.

Also, I want to cut off the 48v supply not one, but 4 places. I made a crap drawing, but I hope it explains everything better.

 

As you can tell by the drawing, there is 3 places i want to cut the supply, though I also want to be able to cut the power from the battery totally.

What I've had in mind was a switch to cut the power to the battery, and maybe a relay or contactor for the 3 other places.

 

I really hope that explained my problem.

Thank you

[Hackentosher]

Why not just get a big ol' cachunk-cachunk toggle switch? 

[NemoTheClown]

10 minutes ago, Hackentosher said:

Why not just get a big ol' cachunk-cachunk toggle switch? 

Toggle switches for 48v DC? Most of those I can find tops at 100mA, and I've got 20A

[RatedBlam]

Isn't high current stuff usually switched with a relay.

Or in most electric bikes the battery is removed when not in operation.

[Hackentosher]

1 hour ago, NemoTheClown said:

Toggle switches for 48v DC? Most of those I can find tops at 100mA, and I've got 20A

Well this guy will do 15a at 250v, or 3750w. Your predicted load is 48v at 20a, or 960w.

[NemoTheClown]

28 minutes ago, RatedBlam said:

Isn't high current stuff usually switched with a relay.

Or in most electric bikes the battery is removed when not in operation.

It is, but I can't use a relay for the main battery power. 
12v switches for the relays and then use the relays for the other places, would that be possible? Also relays seems kinda pricey.
 

 

7 minutes ago, Hackentosher said:

Well this guy will do 15a at 250v, or 3750w. Your predicted load is 48v at 20a, or 960w.

Where do you find that switch? And is it AC or DC?

[NemoTheClown]

Also, would a 12v 200a relay work with my 48v 20a? The effect is higher than what I would use, but the voltage is quiet a bit higher.

[Hackentosher]

I'm a dumbass and forgot to paste the link. https://www.amazon.com/dp/B00ZWWZ5BA/ref=cm_sw_r_cp_apa_jHKBzbQSFBPS0

[NemoTheClown]

1 minute ago, Hackentosher said:

I'm a dumbass and forgot to paste the link. https://www.amazon.com/dp/B00ZWWZ5BA/ref=cm_sw_r_cp_apa_jHKBzbQSFBPS0

Haha no worries. I can see that it is AC. I've read that DC have a higher short-circuit current, so would i still be able to use this?

[NemoTheClown]

18 minutes ago, NemoTheClown said:

Also, would a 12v 200a relay work with my 48v 20a? The effect is higher than what I would use, but the voltage is quiet a bit higher.

The relay I'm referring to is http://www.ebay.com/itm/New-DC-12V-200A-High-Current-2-4W-4-Pins-Car-Automotive-On-Off-Switch-Relay-J9F5/291959544337?

[Hackentosher]

24 minutes ago, NemoTheClown said:

Haha no worries. I can see that it is AC. I've read that DC have a higher short-circuit current, so would i still be able to use this?

All a switch does is connect a couple pieces of metal together to establish an electrical connection. AC or DC.