Battery cut off switch

[Skanmatt]

I recently replaced my 36v 10amp water bottle style battery with a 14 amp battery that I will carry in a frame bag. The ten amp battery had a key switch to power the bike off. Now I have to power down the bike by disconnecting the battery. Is there a switch I can wire into one of the battery leads to safely shut it down? Any ideas?

 

[E-HP]

I recently replaced my 36v 10amp water bottle style battery with a 14 amp battery that I will carry in a frame bag. The ten amp battery had a key switch to power the bike off. Now I have to power down the bike by disconnecting the battery. Is there a switch I can wire into one of the battery leads to safely shut it down? Any ideas?

I use a 40A single pole AC breaker as a switch. Since it's AC, it won't trip on DC current, so I use it as a switch only. Several thousand actuations without any issues, but for $5, cheap to replace if I ever needed to.

 

[Chalo]

Put a high current cutoff switch in either wire of the battery cable, on either side of the plug according to what's convenient.

I use one of these mounted in the side of my battery box:
https://www.ebay.com/itm/193848868144


In the past, I have used one of these mounted to the top tube of the bike frame:
https://www.ebay.com/itm/184069941553

 

[LeftieBiker]

You can also use a DC breaker and get breaker functionality, but I don't know how well they hold up to lots of mechanical trips.

 

[amberwolf]

Does the BMS of the new pack have "enable" wires, or a jumper on the board? If so, you could use any small-current small size switch to do what the keyswitch did on the old battery. If you're not using it anymore you could even use the swithc off the old battery to do it; it's probably already wired this way to the old BMS, which might show you how the new one is setup. Like this pack:
https://endless-sphere.com/forums/viewtopic.php?f=14&t=110243
https://endless-sphere.com/forums/download/file.php?id=287012

 

[LewTwo]

I use one of these mounted in the side of my battery box:
https://www.ebay.com/itm/193848868144
cutoffswitch.jpeg

60 volt switches tend to be hard to find (and expensive). You got a good price.

Same thing on Amazon:
https://www.amazon.com/dp/B07D73RKJX

Just ordered something similar from Amazon:
https://www.amazon.com/dp/B07TWD8YG2

Then I found this which is a tad bit smaller:
https://www.amazon.com/dp/B08612YVG9
This one is only rated at 50 Amps and 50 Volts

 

[Chalo]

When the thing is used as a cutoff, which is to say not under load, then even a 12V rated switch will do. If you use it to quench a full power runaway condition, maybe it's better to consider it disposable like a fuse.

 

[LewTwo]

..... maybe it's better to consider it disposable like a fuse.

Maybe ... I am going to find out.
I have just been plugging and unplugging the XT60 connectors.
Got to be an improvement

 

[LewTwo]

One more candidate:

This actualy a "Battery disconnect" for a motorcycle. Not really a switch but one is screwing and unscrewing a approximate 1/4 inch brass bolt. It is only rated at 12 and 24 Volts DC (80 Amps). However I suspect it is heavy enough to use for an E-Bike up to 25 Amps at 60 Volts DC. This is the smallest one in the series. There is nothing to prevent 'arcing and sparking' between the screw and its contact point.

https://www.amazon.com/dp/B08FY7L2VT

 

[LewTwo]

I use a 40A single pole AC breaker as a switch. Since it's AC, it won't trip on DC current, so I use it as a switch only. Several thousand actuations without any issues, but for $5, cheap to replace if I ever needed to.

Something like this ?
https://www.amazon.com/dp/B01JE7SRP4

 

[fatty]

I use a 40A single pole AC breaker as a switch. Since it's AC, it won't trip on DC current, so I use it as a switch only. Several thousand actuations without any issues, but for $5, cheap to replace if I ever needed to.

It may not be a rational fear, but after having a house circuit breaker fail closed (contrary to switch position), I wouldn't use a circuit breaker here.

Not really a switch but one is screwing and unscrewing a approximate 1/4 inch brass bolt. It is only rated at 12 and 24 Volts DC (80 Amps). However I suspect it is heavy enough to use for an E-Bike up to 25 Amps at 60 Volts DC.

I would not suspect this. In fact, I think the term "rated" is a bit generous for these Chinese eBay/Amazon parts.

If you do play with stuff like this, please use a proper 80VDC Cooper-Bussman ANN fuse upstream.

 

[E-HP]

I use a 40A single pole AC breaker as a switch. Since it's AC, it won't trip on DC current, so I use it as a switch only. Several thousand actuations without any issues, but for $5, cheap to replace if I ever needed to.

Something like this ?
https://www.amazon.com/dp/B01JE7SRP4

Yup. This is the exact one, but any should work:
https://www.homedepot.com/p/GE-Q-Line-40-Amp-1-in-Single-Pole-Circuit-Breaker-THQL1140/100184166

 

[LewTwo]

Well I found another possibility: Carling Technologies AC/DC Toggle switches (DK/EK Series).
These are rated at up to: 20 Amps @ 125 Volts, 10 Amps @ 250 Volts (DC or AC)
If one extrapolates that down to 60 Volts then you get about 40 Amps.
Rated for 25,000 cycles.

The ones I found are Double Pole (one could use only one side for single pole).
They are also big with a 1 Inch by 2 inch footprint however they use a single 1/2 inch diameter mounting hole.
You can also add a 15/32-32 rubber boot if you are concerned about dirt or water.
The terminal screws are #6-32 (a little over 1/8 inch diameter) with approximately 1/4 inch diameter heads.

20 AMP 125 Volts DPST https://www.amazon.com/dp/B07J2VRDGP
16 AMP 125 Volts DPST https://www.amazon.com/dp/B005T69LNM


PDF Data Sheet: https://www.carlingtech.com/sites/default/files/documents/DK_EK-Series_Details_%26_COS_0.pdf

Follow up:
The dimensions on the datasheet are for the 20 Amp version.
The 16 Amp version is a bit smaller:
44.75 mm long by 21.25 wide by 15.5mm deep
terminal screws threads are 3.3mm diameter with 6.0 diameter heads.