key lock switch question

[tmho]

I am planning to have a key lock switch for my 16s5p 48V 15AH LiFePO4 battery pack. But most key switches I found are just 1 or 2A. The maximum I could find is just 10A. I need to draw 20A from the battery pack. Does anyone has a source for 20A key lock switch? Or should I use a relay for 20A?

 

[Tench]

Can you not use the key switch to switch the controller on and off? if it has to be the pack leads then a circuit with some fets switched on by the key maybe the way to do it.

 

[Drunkskunk]

Those key switches aren't very robust, and their contacts aren't designed for the high voltage spikes your battery will give it during switching. Putting them just on the switch feed of the controller is an option, but the battery will still drain even when off if the main power wires are connected.

An alternative is a large battery switch like this:
http://www.amazon.com/BATTERY-CUTOF..._2?s=automotive&ie=UTF8&qid=1395175321&sr=1-2

 

[tmho]

Can you not use the key switch to switch the controller on and off? if it has to be the pack leads then a circuit with some fets switched on by the key maybe the way to do it.

Thanks for the reply. I am trying to use it to switch on and off a custom made battery pack. Just like most ready made e-bikes, their battery pack usually build with a key switch to turn the battery on and off. I just could not find such switch.

 

[tmho]

Those key switches aren't very robust, and their contacts aren't designed for the high voltage spikes your battery will give it during switching. Putting them just on the switch feed of the controller is an option, but the battery will still drain even when off if the main power wires are connected.

An alternative is a large battery switch like this:
http://www.amazon.com/BATTERY-CUTOF..._2?s=automotive&ie=UTF8&qid=1395175321&sr=1-2

Thanks for the suggestion. That one seems without a key, the red part seems to be the handle for turning. With a key, I think the e-bike will be a bit more difficult to be stolen.

 

[Drunkskunk]

.

 

[r3volved]

That red part is the key
That's what I use and it's worked great. I got mine from an industrial machine supply place. It's a bit big and bulky, but it can be waterproof if sealed and it's DC rated to my setup (48v) @ 50a.

 

[r3volved]

This is more what you want
http://www.amazon.com/gp/aw/d/B007O0BBFM/ref=pd_aw_sbs_2?pi=SL500_SS115

 

[tmho]

That red part is the key
That's what I use and it's worked great. I got mine from an industrial machine supply place. It's a bit big and bulky, but it can be waterproof if sealed and it's DC rated to my setup (48v) @ 50a.

Thanks for the reply.

 

[r3volved]

For size, the flat part is about the same diameter as a 250ml red bull can. The key hole part is about an inch long without key. Needs about 1/2" wide x diameter long x 1" deep at the non-key side.

 

[d8veh]

Most controllers have a low-current "ignition" wire often labelled "lock", "anti-theft" or something like that. you can put any small switch on that, which will cut down battery drain to more or less nothing. It's normally a single red wire or a pair of red and yellow or red and orange wires.

 

[tmho]

Most controllers have a low-current "ignition" wire often labelled "lock", "anti-theft" or something like that. you can put any small switch on that, which will cut down battery drain to more or less nothing. It's normally a single red wire or a pair of red and yellow or red and orange wires.

Thank you very much for the information. I will sure follow that if I could not find a simple, small and high-current key switch.

 

[d8veh]

If you have that wire, you don't need a high-current switch. That's the whole point of it. Which controller do you have?

 

[r3volved]

I use the high current key switch between my battery and everything else. Then also a toggle switch at my left thumb to toggle power to the controller.

Battery > Fuse > Key > Toggle > Controller

This allows me to 'turn the bike on' with my key and power lights and other accessories and whatnot. My left thumb switch is then a 'motor ignition' so I can turn the controller on and off from the easiest position.
Nothing works without key-on. Motor doesn't work without key-on && toggle-on

 

[izeman]

Most controllers have a low-current "ignition" wire often labelled "lock", "anti-theft" or something like that. you can put any small switch on that, which will cut down battery drain to more or less nothing. It's normally a single red wire or a pair of red and yellow or red and orange wires.

Thank you very much for the information. I will sure follow that if I could not find a simple, small and high-current key switch.

sorry. but this is WRONG. if we're talking about those 'infineon and clones' type controllers. if you switch to off, the caps are still powered and will drain your battery. depending on soc and controller size (cap size inside) this can take from only days to some month until your battery is drained.
this switch is to temporarily (during a days tour) turn the bike off. but not for long time shut down.
if you need something like that, and don't want or can't disconnect the battery then search for 'ebike master switch' and build one. these circuits can be switched on/off with a small current switch and will use microamps.

 

[tmho]

If you have that wire, you don't need a high-current switch. That's the whole point of it. Which controller do you have?

I have the GNG one which has that wire.

 

[tmho]

I use the high current key switch between my battery and everything else. Then also a toggle switch at my left thumb to toggle power to the controller.

Battery > Fuse > Key > Toggle > Controller

This allows me to 'turn the bike on' with my key and power lights and other accessories and whatnot. My left thumb switch is then a 'motor ignition' so I can turn the controller on and off from the easiest position.
Nothing works without key-on. Motor doesn't work without key-on && toggle-on

Good idea. Hope I could find a suitable high current key switch soon.

 

[tmho]

Most controllers have a low-current "ignition" wire often labelled "lock", "anti-theft" or something like that. you can put any small switch on that, which will cut down battery drain to more or less nothing. It's normally a single red wire or a pair of red and yellow or red and orange wires.

Thank you very much for the information. I will sure follow that if I could not find a simple, small and high-current key switch.

sorry. but this is WRONG. if we're talking about those 'infineon and clones' type controllers. if you switch to off, the caps are still powered and will drain your battery. depending on soc and controller size (cap size inside) this can take from only days to some month until your battery is drained.
this switch is to temporarily (during a days tour) turn the bike off. but not for long time shut down.
if you need something like that, and don't want or can't disconnect the battery then search for 'ebike master switch' and build one. these circuits can be switched on/off with a small current switch and will use microamps.

Thanks for the suggestion. I will make sure that "ignition" switch will not drain my battery before trying it. For building that "ebike master switch", it seems that it is too technical for me.

 

[d8veh]

The caps won't drain your battery. At most, you'll leak a couple of miliamps, but it's normally microamps. It'll take at least three months to drain a 10aH battery, but the advice is still good. Just for peace of mind, it's a good idea to disconnect if your going to leave your bike for more than a couple of weeks. It's a lot neater and easier to use the ignition wire than wiring in a massive boat switch. I do it on all my bikes now.

 

[drsolly]

I have a switch pretty much like that. I had a 12V jumpstarter/airpump thing from a car shop, but after several years, the lead-acid battery no longer held charge. So instead of just chucking it, I dismantled it, and got:

4 meters of nice 6AWG cable
An analog voltmeter
An air pump
Two small switches
And a high-current switch, which until you posted, I didn't know could handle 60v 300A.

I'll use it next time I need a heavy duty switch on the bike. By the way, you can get them for about $6 on Ebay.

 

[r3volved]

I have a switch pretty much like that. I had a 12V jumpstarter/airpump thing from a car shop, but after several years, the lead-acid battery no longer held charge. So instead of just chucking it, I dismantled it, and got:

4 meters of nice 6AWG cable
An analog voltmeter
An air pump
Two small switches
And a high-current switch, which until you posted, I didn't know could handle 60v 300A.

I'll use it next time I need a heavy duty switch on the bike. By the way, you can get them for about $6 on Ebay.

They're not all 300A @60v
Mine's only 50A @48v

 

[Tench]

You put a key switch in the low current controller on/off circuit and use a pack isolater like this, which would also double as a fuse, you could also still have your handle bar mounted kill switch in series with the key switch.

 

[r3volved]

You put a key switch in the low current controller on/off circuit and use a pack isolater like this, which would also double as a fuse, you could also still have your handle bar mounted kill switch in series with the key switch.

That's a good idea too
Where did you pick that up?

 

[Tench]

Where did you pick that up?

I bought a bag full of them last week, NOS, unused.

 

[rborger73]

Where did you pick that up?

I bought a bag full of them last week, NOS, unused.

Have you tried one out yet to see how it handled things? What volts and amperage you running through them if you have?