Alien Aurora - I'm starting an Alien family!

[GSol]

After being very happy with my Alien Pulsar folder, I have been on the lookout for an Aurora second hand for a while. Finally found one and picked it up on the weekend

Got a good deal - travelled over 200miles to collect!
Haven't had a chance to check it out in detail, but my initial inspection and test rides have (so far) picked up the following:

The handlebar has some play in one of the joints - must locate this.
The sprung seat post has a bit of radial play in it - will change for an unsprung one.
The battery rack is missing 2 screws/bolts, so it rattles and bounces! Must fix that ASAP!
The rear light doesn't work - probably loose wiring - will sort that out when I get time.
Missing mudguards - which are the best fit for this bike?
The motor is a very different feel to the Pulsar. Makes a different sound and is a lot smoother, except at initial take-up, is feels "nervous" for lack of a better description. Is this normal?
Weird thing is, the Aurora feels slower than my pulsar. Must wire up the speedo and see what the figures say...

Anyway, looking forward to sorting it all out and enjoying the new addition to the family!

 

[johnc461165]

Hi GSol, I have a 6 month old Aurora and there is some radial play in the seat post, surprised that you feel it's slower than you expected, the motor is very quiet and delivers power smoothly maybe you need time to adjust to the bike. Good luck John

 

[Deleted member 4366]

I hope you enjoy your new bike and make a full review of it once you've done a few miles. I'd be interested to know what controller's in in it if you ever have a look at it. I don't need the maker but just the rating in amps. It should be quite a fast bike - and fast accelerating, which makes me wonder if all is not what it should be. I've seen a few Auroras come up on Ebay with knackered batteries, which makes me think that the battery isn't up to the demands of the motor, so, when yours comes up for replacement, you should think about at least 15AH or lipos. BMSbattery make a nice rack-fitting battery of 15aH.

The nervous takeup could be because it's running sensorless. I don't know whether the standard motor has hall sensors. Most of the BPMs do, which again makes me wonder whether it has the standard controller. It might be a good idea to have a look at it, see if it has the connector for the hall sensors, and see if it's connected.

 

[NRG]

Its an LDZS controller rated at 9A continuous, 18A max...20~21mph top speed.

 

[Deleted member 4366]

Its an LDZS controller rated at 9A continuous, 18A max...20~21mph top speed.

That's not many amps. Is it a 6 FET controller?

 

[NRG]

Yes, 6FET...

 

[Scottyf]

I would have assumed that should have been a 9 fet controller.
I'd be a bit more mythed if it was a 6 fet dishing out the amps. Still at those powers it should always work as its effectivley underpowered.

Which is probably why it seems so quiet and free running.

I noticed how quiet the bpm motor way when comparing it with the smaller bafang. But I put a little of it down to the fact that it was rear fitted and not front fitted.

 

[Deleted member 4366]

I'm getting 20 amps out of my 6 FET controller on my Cyclamatic. It seems to be OK at that power, but I've got it strapped to a big heatsink, which probably helps. For a BPM motor, like the Aurora has, I'd uprate to 9 FET 25amp controller to get the hill-climbing ability because I'm fat and lazy. I guess a fit cyclist would probably be happy with 18amps.

 

[jerrysimon]

All this talk of controllers you guys might be able to answer. Is there an easy way to lower the cutout voltage of my controller or do you need an interface cable etc to get to the firmware ?

Regards

Jerry

 

[NRG]

The amp limit is there firstly to protect the battery so upping to 25amps on the Aurora would be a no go IMHO unless the stock battery was replaced. Certainly 25amps would be fantastic for hill climbing for a short while!

I've pulled 21 amps on the e-crazyman 6fet controllers without an issue other than the standard Bafang 250w motor makes a lot more noise under the strain...Im now running a more sane 18amps.

 

[Scottyf]

When I upped the amps on the Bpm from 20amp rated to 27 uning the shunt modification its only really made a difference on take off speed (as you'd expect) the hill climbing itself didn't really change all that much.

I think i probably just put a bit more effort into cycling. Either 20 or 27 i've never had to change to a lower gear. i'm stuck in my last highest speed gear.
(Derailler cable has broken so i have three gears now using the front mech).

Good job i have electric otherwise it would have been a hard cycle the last week.

 

[NRG]

All this talk of controllers you guys might be able to answer. Is there an easy way to lower the cutout voltage of my controller or do you need an interface cable etc to get to the firmware ?

Regards

Jerry

What controller Jerry?

 

[jerrysimon]

Ah that would help wouldn't it NRG

I have started a new thread rather than hijack this one.

Regards

Jerry

 

[GSol]

Don't mind the hijack hehehe... interesting stuff - lots to learn!
Will take some pics of the bike and the components suggested on the thread and post if this weekend. Thanks for all the hints, want to get it to its best running condition!

I have 2 battery packs with the bike, one is a dud and one works perfectly. Are there any companies that refurb the batteries? Or should I first open it up and check what the problem is? Any thread on the forum that can guide me through that process?

 

[Deleted member 4366]

There's nothing complicated about dismantling the battery. Just remove the two end caps and slide out the contents. Take a photo of it laid out and we will comment on any likely defects. It's interesting that you got a dud one because there seem to be a lot of Auroras with dud batteries. If it were my bike, I'd get a 15aH battery from BMSbattery and while you're at it, get one of their 9FET controllers that cost very little and the postage will be free because they'll pop it in with the battery. This set-up will give you effortless riding.

 

[GSol]

So I've managed to do some work on the Aurora.
- handlebars set properly, there was dirt in the moving parts and they were loose. Cleaned and tightened, now its perfect.
- Seatpost still has a bit of radial play, but after tightening the suspension bits up which were loose, its much improved.
- Brakes were appalling! Bike almost couldn't stop when I tested it. It's my first time working with disc brakes, but after some rust removal and adjustment from scratch - they are not as complicated as I've heard others say - they are both working excellently with almost no noise!
- Opened up the box housing the controller and checked all the wiring and everything seems to be in order. (see photos below). It is a 9A continuous 18A max controller.
- Opened up the "dud" battery and measured all cells reading between 3.96 - 4.15v and total voltage reading at 40.6v. Not sure what it is supposed to be normally, but that seems right to me. Before I put it back together, is there anything else I should check for?

The results of my efforts:
- Bike definitely needed the cleanup and adjustment!
- Acceleration is MUCH better, can definitely tell the difference between lo, mid and hi power settings.
- Need a 36v 5W light bulb for the standard rear light (anyone know where I can get this?)
- Still a strange sound coming from the motor when throttle slightly open. It sort of ticks/clicks and then hums (loudly) and also squeeks/grates. This ONLY happens when the throttle is just slightly opened and held there. It disappears once the throttle is opened further. I have recorded this on this clip: Alien Aurora Electric Bike Motor Sound - YouTube

The controller:

The wiring of the controller:

The insides of the battery:

The voltage:

 

[johnc461165]

Just listened to the sound of your motor on u tube, (awful) my Aurora is not much more than a hum which unless I try to hear it is lost in general background noise. I can only suggest that the internal gears may be in a bad way or it could be a bad bearing which sounds more likely, sorry I cant be more helpful, good luck. John

 

[GSol]

Just listened to the sound of your motor on u tube, (awful) my Aurora is not much more than a hum which unless I try to hear it is lost in general background noise. I can only suggest that the internal gears may be in a bad way or it could be a bad bearing which sounds more likely, sorry I cant be more helpful, good luck. John

Thanks for the reply, I'm hoping it doesn't get worse, for now it's only if I linger on slightly opening the throttle. If I open it quick enough, it settles into the very silent hum that you are describing, with just a tiny squeak as it starts. Used the bike for the first time to work this morning, its very good, and breezes up hills!

How difficult is it to open up the hub motor?

 

[johnc461165]

I have only opened a Powabyke front hub motor, tight screws and removing the freewheel are probably the hardest part then it's just a matter of removing the the motor end plates. I think you should be able to get a bulb from Alien.

 

[Deleted member 4366]

It sounds to me like the roller clutch is slipping. the rollers ride up a ramp until they're wedged when the motor starts to rotate. For whatever reason, at low torque, there isn't enough oomph to wedge them. Possible reasons: 1. Water has got in through the cable entry point - normally because the cable doesn't go down from the exit before going up to the controller - and so the clutch has gone rusty. Yours goes down so maybe OK. That would also account for other general noise. 2. lack of grease causing general dryness and unsmooth operation especially if it hadn't been used for a while before you got it. 3. Other contamination like a bit of dirt in the clutch.

If it's reason no 2, it might go away as soon as you start using it. If it's 1, then the motor has to be opened up which isn't too difficult on these. I haven't needed to do one yet, but I believe that you just remove the screws around the periphery of the side plate and tap it apart after removing nuts etc from the shaft. Whatever the reason, It would be a good idea to open it up and re-grease everything and then it'll be as smooth as silk and all the worrying will be over.

I can't see a hall sensor connection, so it's probably a sensorless controller, which accounts for the ticking and juddering at the start, Nothing to worry about there.

Regarding the battery,, which is made of 10 groups of 3.7v cylindrical cells, 9 per group from what I can see in the photo (edit: or are they 3 per group prismatic cells?) I think you need to charge it up and check that all the cells reach the same voltage of about 4.2v. They should all be equal within 0.05v if the BMS does its job properly. Then run it down about halfway and check the cell voltages again. The cells are in groups, so any one in a group could be faulty so that one group will go down quicker than the others. So.if it goes way out of balance as the pack voltage falls, you can identify the group and then check all the connections within the group.That means at each end of each cell plus the BMS wire. If all connections are OK, then it's faulty cells.