New way of E-Bike protection ( automatic fuse )

[Bazaki]

People,

I really love to ride my Ebike 18s 2p Lipo 66,6v 10ah battery set at 80 amp lyen controller at a Crystalyte High Torque motor. 85 km/h top speed and very very good acceleration.
This year I rode about 2300 km with it. I also ride with my 2 year old daughter with the ebike. ( speedswitch 1 set at 25km/h ) Also my wifes rides the bike.

BUT, I have seen some dangerous things, ofcourse we all know about the Lipo-fires, so in case of a fire we all must get away from the ebike.
Another point danger is the throttle, a week ago I was cleaning my Ebike in the garden with hose, just a small amount of water came inside the frame-bag so the throttle connector got a bit wet, the Ebike was switched on and also it was set at Speedswitch 3. So 80 amp 70v and the bike flew away. No accidents and nothing broken. Also sometimes I have seen that My speedswitch is set at speed 1 but sometimes it rides at speed 2, because if there is no 3-way speedswitch connected to the controller, the controller will perform at speedswitch 2 set at the software from the controller.

So full throttle at speed 1 with 100% throttle ( 25km/h) and with suddenly a lose connection can result in 100% throttle at speed 2 which can result in a very bad wheelie.

An Ebrake won't help it is too fast, also with some water ( rain at/in the throttle/connectors) that can result at 100% power, also I would go 60km/h and some how the throttle will hang at 100% I don't think my brakes are strong enough to stop me from having an accident. A good ebrake will be a solution but I want to be 100% sure that this will work so I have thought about the following solution.

I did some tests and 70V with 30A will not result in an unwanted wheelie so, I was thinking to install an Automatic fuse of 30A in parallel of the main on/off switch. So I want to ride safe with my daughter or someone else will ride my ebike, I leave the main switch at off and set the automatic fuse of 30a at on. One can ride the Ebike normal with still 2000 watt of power, but be a bit easy at the traffic lights, accelerate gentle and everything is fine. But as soon as so accelerate too fast then "CLICK " the fuse switches the power off. You can install it near the battery and switch it back on.

So when I ride in the rain, or something else will happen the power is always 100% off above 30A.
70v x 30a is still 2100 watt which is good enough to ride about 65km/h but as soon as I would hit the brake the Automatic fuse switches off beacause you would drain to much amp.

A few friends of mine that build an Ebike with the same setup all have had an unwanted wheelie, 1 of them with a broken foot, he thought the speedswitch was set at speed 1 instead of speed 3.

I think the Automatic fuse solution can prevent a lot of unwanted wheelies, I have to do some more testing because I think there is a small delay in the Automatic fuse.

Any thoughts ?

 

[bigmoose]

I support your discussion of this topic. At the power levels most utilize here an accessible emergency disconnect is imperative. Your discussion on automatic fuses (which we call "breakers") is useful. We have ignored safety a bit too long at these power levels.

 

[Ypedal]

Only method i can think of to be effective is a tether, like they have on seadoos, if a full power ( when you dont expect it ) situation happens, you likely will not have time to reach for a switch... E-brake cutoff is next but even that is a bit of a strech imo..

 

[rebelpilot]

Another point danger is the throttle, a week ago I was cleaning my Ebike in the garden with hose, just a small amount of water came inside the frame-bag so the throttle connector got a bit wet, the Ebike was switched on and also it was set at Speedswitch 3. So 80 amp 70v and the bike flew away.

No security cam footage available? That would have been a great video. It's good to hear nobody was hurt.
I have experienced a few unwanted wheelies, and everything happens so fast that I don't think any of the breakers I have would trip quick enough.
If the breaker isn't fast enough I suggest you try to make better connections to the speed switch, maybe hardwired, and maybe a separate switch that forces the controller to speed 1, regardless of the position of the speedswitch.

 

[Bazaki]

Ofcourse we can improve all connections and make them almost waterproof but I just don't trust it 100%, an ebrake is indeed the solution to stop a wheelie, a wheelie will happen too fast. At Wikipedia I found out that the a regular auto-fuse has a delay of 10ms. I think that is fast enough.

 

[Spacey]

I had a similar incident the other day, had the bike upside down and was changing over the suspension on my Greyborg frame with an HS3540 motor at 66v 40amps. I had left the bike on and when I lifted the wheel with my hands it moved the bike forward which turned the throttle.... I nearly lost my fingers!

 

[kfong]

One problem is you don't want power to cut off on you when going through an intersection. A more secure switch setup or separate low power ebikes would seem more safe.

 

[bigmoose]

One problem is you don't want power to cut off on you when going through an intersection. A more secure switch setup or separate low power ebikes would seem more safe.

I guess we have to design our emergency cutoff so that it is reliable against "false positives." For example fighter pilots can eject from the aircraft. A false positive would be higher risk than staying in the bird if all is A-OK. It can be done, I believe.

 

[Ypedal]

http://cgi.ebay.com/ebaymotors/ECONOMY-ATV-RACING-HANDLEBAR-MOUNT-TETHER-KILL-SWITCH-/250697403264?pt=Motors_ATV_Parts_Accessories&hash=item3a5ebacb80

 

[beast775]

I agree something is needed,but ive been thinking for yrs and still cant decide.thought of a seat switch activated when seated?but that has its problems also.all my ebike accidents have happened in wierd situations.but a tether stops most while riding.

 

[auraslip]

1) Ebrakes will stop a runaway WOT condition.

2) Even shitty wuxing ebrake levers and rim brakes, should the ebrakes fail to disengage the motor, will be enough to stop the bike long enough for you to lay it on it's side and start unplugging things.

3) Controllers (well, some at least) will override a WOT condition if the 5v throttle line is shorted to the throttle sense line.

I'm sorry, but I just can't think of a situation where the throttle AND the ebrakes would fail at the same time. Of course, you were watering your bike with a hose, so that's a bit different.

One fun thing that happened to me though is getting my twist throttle caught on some jackets on a coat rack in my kitchen. This put rubber all over the floor, and even took some skin off my leg. To be fair though, I was drunk. Come to think of it, all my ebike injuries involve alcohol. A much better idea would be a breathalyzer on my bike.

 

[vanilla ice]

I think a "dead man switch" (which disconnects the battery from the controller) and the std ebrake cutout.. having both is a good idea. My brake cutout on my scooter did not function when the controller blew out and it went WOT.

I know some motorcycles and ATVs now come with a right side up switch which cuts the engine if the vehicle tips over. That might be interesting to play with.

 

[EBJ]

for my setup I am using a kelly controller, which has a "brake-switch" input. I just run a line up and back that keeps a normally closed relay open, and I attach that line to my body. So I have a tethered "dead-mans" brake. That way if I accidentally wheelie and eat-it, the tether will trip the brake-switch, which I have set to engage 20% braking power. an un-manned bike at 20% braking power seems to be enough to keep it from running into things/people. I also suppose if your controller went WOT, you could pull the tether out and engage the brake-switch which is made to disengage the throttle.

 

[Bazaki]

A dead-man switch would not be my perfect solution, I can hang on to my bike but flip over, also I still can hang at my steer while falling down.
A switch at the saddle is also not going to work for me, I like to go offroad.

I have thought about a switch at the handlebar like this.
http://www.makita.nl/lp/custom/images/UH6570_part_3.jpg

So you have to hold the left handlebar and throttle together if you want to ride.

Me and all of my Ebike buddies have had an almost-accident or a accident, as I read above some of you also have had experienced a flip-over or similair kind of error.

A guy at the forum was posting a few months ago that his ebrake didn't work, the youtube video did show there was a bad connection inside the wire and was causing a really dangerous error.

I just don't 100% trust kind of signal wire ebrakes or amp. limitations, with water or snow or broken wires weird stuf can happen so I prefer to cutt all power.

I think I need a 30amp Auto-fuse for a safe ride and a second 90amp Auto-fuse for a wild ride.

Does anyone has experience with an Automatic-fuse ? How do they handle, how long is their delay in practice ?

 

[spinningmagnets]

A while back I had a treadmill pointed towards the TV, for when there was snow outside (I'm a wimp, clear-weather riding only). The treadmill had a magnets on a lanyard as a dead-man switch that I (of course) just left on the treadmill rather than attach to my wrist.

I don't know how easy/difficult it would be to adapt one to an E-bike, but I see free treadmills set out for the trash frequently. It could be a cheap experiment, and between jet-ski's/snow-mobiles/treadmills, the parts are certainly buyable as a new replacement part.

Also more difficult and slower for a thief to pedal away, rather than E-ride.

 

[amberwolf]

I was thinking to install an Automatic fuse of 30A in parallel of the main on/off switch.

It must be in *series* with the switch, to do what you want.

I use a larger breaker with an easy to throw switch right between my knees on the toptube of CrazyBike2 as a main power switch and a kill switch. If something really went nuts it will pop, but it'll sustain all the power I need to ride the bike, just fine. I can easily reach down and flip it off if I have to, if anything went wrong like uncontrolled WOT.


On DayGlo Avenger, I use a keyswitch in the handlebar fairing to cut power; again I could turn the key off while riding if I had to, though it's not as fast an action to do as flipping a switch.

Just keep in mind that for either your automatic fuse (breaker) to work, the battery cable to the controller has to run thru it, so if you have it on the handlebars, you must run the loop of your main battery cable (either positive or negative, doesn't matter) from the battery up to the breaker and then back down to the controller.


In both of my cases, the battery wires pass thru the area the breaker or switch is in on the way to the controller anyway, so I don't have to route an extra loop of wire up to it. But usually the controller is in or near the battery box, adn that's not usually on the handlebars, so you end up with a long battery cable up there.


Regarding the water issue, I highly recommend using something like Vaseline or automotive battery terminal grease to fill your connectors before plugging them in. It will keep water out of them, but still allow good electrical connections. There are also various waterproofing greases available for connectors; I've seen at least three kinds on automotive and motorcycle wiring harnesses, in their connectors. So far the connectors I have remembered to do this to have not had a problem, but even here in Phoenix, AZ, where it's almost always very dry, I *have* had problems in connectors that I did *not* do this to.



Many breakers require a sustained overload before they pop, sometimes half a minute or more, depending on how *much* of an overload. You'd probably want to get a sample unit and test on the bench with a power meter to determine the overlaod points for your breaker(s) experimentally, since there probably isn't a data sheet to give a chart for most of them.

 

[Dee Jay]

My wife came very close to either frying the controller or flipping my ebike over! I realized how dangerous these unrefined ebike kits really are when I asked her to practice riding for the first time. MY BAD! My noob ass didn't think I needed the motor-cut brake levers so I didn't order them. She had the left brake lever applied and the throttle turned, about half way, I think. I nearly had a heart attack! I asked her calmly to let-go of the throttle! I wouldn't be able to forgive myself if she got hurt.

I think we have been conditioned all our lives to feel for the rumble of engines to get a sense of how much power we are about to use. Electric vehicles just don't have this rumble so we need to create it for the average EV consumer. An EV noob should feel this rumble on the handle bar or steering wheel or even on the "gas pedal".

It's very easy to create this rumble on the handle bar. It's nothing more than a tiny motor that is spinning an unbalanced metal weight! That's all it is.. ideally this rumble motor should slow to a stop as you accelerate so it doesn't drain the battery.. but the easiest thing is to just have it shut off at a certain a point of the throttle twist.

another issue is with these generic hall sensor throttles, they're just not stiff enough. It should be as stiff as a motorcycle throttle. why? because that's what we're used to.

Another possible low tech solution is a combination of :
*higher resolution hall sensors
*adjustable magnet to sensor distance
*throttle limiting lock

 

[Bazaki]

Well I tried using a 220v AC 32amp circuit breaker but even at a peak of 100a it won't break
And a few seconds at 80Amp it also won't break, maybe because it needs 220v AC ?

I will try a 16a circuitbreaker maybe it will break at 70v 30a.

Maybe the Mastervolt circuitbreaker in my startpost 30a will break because it is DC ?

 

[Burtie]

Be careful not to use a breaker with a significant inductive component (ie operated by an electromagnet).

Adding inductance to the battery leads will give your controller a hard time, it can generate voltage spikes which might kill your electronics.

Burtie

 

[Bazaki]

http://nl.wikipedia.org/wiki/Bestand:Circuitbreaker.jpg

I think it works like the above, so I have no idea, I am not able to break the circuit with it, so maybe it will never break because it needs 220v ac ?

Maybe this will work for 80amp
http://www.grainger.com/Grainger/COOPER-BUSSMANN-Circuit-Breaker-6CHZ8

And this 30amp for the safe ride
http://nl.rs-online.com/web/p/thermal-automotive-circuit-breakers/7234831/

 

[Burtie]

Nice picture.

Item 7 is the dreaded inductor (coil) in series with the current path.

These devices use a combination of electrical heating and electro magnetic mechanisms to detect over current conditions.

 

[vanilla ice]

A wheelie cutoff would be neat. Might not be cheap to do though. I wonder would a "tipover switch" from a motorcycle rotated 90 degrees and tilted just right work as a wheelie switch.

I have some "pal" type fuses from my auto spares I might try. Meant for 12v DC but I think they will be ok with 36 to 60v.. They are only a couple bucks each for anybody wanting to try some.

 

[Bazaki]

Looking good, is there a brandname or something on them ?
http://nl.rs-online.com/web/p/thermal-automotive-circuit-breakers/7234831/

This is something that looks like them, but the 32a circuitbreaker 220v AC I now have I also can use as a switch.

A flipover switch is not going to work for me, I like offroad with hill climbing and besides that, I think you will fall anyway, the flipover switch will cutoff too late I'm afraid.
Also it is not only for a flipover, it is also when there is a lot of rain since I have noticed some errors with water at the throttle/wires/controller. WOT in the rain is uncool. a 30a fuse would break when I hit the breaks.

 

[alsmith]

http://cgi.ebay.com/ebaymotors/ECONOMY-ATV-RACING-HANDLEBAR-MOUNT-TETHER-KILL-SWITCH-/250697403264?pt=Motors_ATV_Parts_Accessories&hash=item3a5ebacb80

I've got one of these. Not yet wired in but on the bars ready to do. The bit that pulls off isn't going to fall off- it needs quite a tug. The only thing is you need to connected by the tether, or have enough time to grab it to stop. I'm not sure though- it'll not take the full amps of the battery so would need to go in the switch circuit.

 

[kfong]

An electronic switch is a easy approach for an emergency stop. I built a smart switch that has the off button in an interrupt routine. It instantly disconnects the power to the motor before shutting itself down. This can be paralleled to other remote switches that have normally open contacts. As for shutting down with a current limit like a fuse, that can be easily done in software, but not anything I found a need for.

On further thought, detecting a short scenario would be a good feature. Something like a high current limit for over a set time.