48v high current switch

[Projectitis]

Hi all,

Sorry if this has been asked before - I have searched and not come up with anything yet, so feel free to point me at other threads if this is a duplicate.

I want to add a switch between the battery/BMS and the rest of the circuit (e.g. controller, 12v aux system) to kill all power when not in use. I have a 1000W motor and 48v battery, so theoretically around 20A maximum draw, so I'm thinking something that handles 30A at 48V.

Do I need something like a relay, or will a switch rated (for example) 20A at 110V work ok for 30A at ~50V? I'd much rather have a nice, relatively small rocker, than having one of those industrial ON/OFF panel switches too, that you see on table saws and other workshop equipment

For example -
will something like this be suitable?
I don't really want something like this!

Any ideas on suitable switches?

Thanks,
Peter

 

[gwhy!1]

Hi all,

Sorry if this has been asked before - I have searched and not come up with anything yet, so feel free to point me at other threads if this is a duplicate.

I want to add a switch between the battery/BMS and the rest of the circuit (e.g. controller, 12v aux system) to kill all power when not in use. I have a 1000W motor and 48v battery, so theoretically around 20A maximum draw, so I'm thinking something that handles 30A at 48V.

Do I need something like a relay, or will a switch rated (for example) 20A at 110V work ok for 30A at ~50V? I'd much rather have a nice, relatively small rocker, than having one of those industrial ON/OFF panel switches too, that you see on table saws and other workshop equipment

For example -
will something like this be suitable?
I don't really want something like this!

Any ideas on suitable switches?

Thanks,
Peter

you could use sometihng like this http://www.ebay.co.uk/itm/1-x-Black-Button-4-Pin-DPST-ON-OFF-Car-Rocker-Switch-AC-250V-15-30A-K201N-/161310834782?pt=LH_DefaultDomain_3&hash=item258ee0005e and parallel the contacts should be ok for 20-30A

 

[dnmun]

you can use a small switch on the BMS to turn off the circuit current or short the gate to source on the output mosfets. so that would turn off the battery.

 

[Nobuo]

the one gwhy! shared is the minimum it would work with safety. Others with lower amps rated will disintegrate over time

 

[d8veh]

If you have a BMS, it already can switch off the power, so it doesn't make sense to add another switch. Show us a picture of your BMS and we can probably advise a simple way to add a switch. For that, you can use any switch you want.