Blew out sensorless ctrlr again-- what's reliable?

[fitek]

Give me 10 minutes and I can kill these 36v ecrazyman things pretty easily. I'm rather tired of swapping out FETs SOOooo...

Anything sensorless with a bit more longevity out of the box? (that doesn't cost like 5x as much)

I'm using a Bafang hub motor.

 

[Russell]

I'm using this one with my Bafang which I've been running sensorless for 210 miles.

http://endless-sphere.com/forums/viewtopic.php?f=4&t=13659

It didn't work great sensorless however until I locked up the clutch to make the Bafang non-freewheeling.

http://endless-sphere.com/forums/viewtopic.php?f=4&t=10458&start=45#p212576

-R

 

[Affliction]

Don't listen to Russell..... :x

Wilderness Energy makes a controller for their 2008 models that is instant start and sensorless!
You can get one from http://www.itselectric.ca
I've seen one in action, it figures out how to run the motor with no sensors and then it goes!
You don't need to frock up your freewheel for this.

 

[dogman dan]

I was just about to say, I run a 5304 on that controller. I get them from High Tech Bikes. Its good for 36-48v 22 amps. I like em a lot, but wish they had a 30 amp model. But that doesn't mean you can't kill one.

 

[Russell]

One more thing; if you are blowing out FETs there might be a problem with the motor, wiring or connections so that should be considered as well.

Regarding the Aotema unit; I'm sure it's a fine controller but doesn't it use 60V FETs? That's not a problem with a 36V pack but it might well be at 48V. It does use 12 FETs so it's probably reliable too however I have not used it so I can't speak to that. The ecitypower/bmsbattery controller that I have does use 75V FETs and 63V caps and I have been using it at 48V with no problems, it's also roughly half the price of the Aotema PLUS it features cruise control, which I love, and regen/e-braking which I haven't used so I don't know how well that works.

-R

 

[fitek]

The ecity unit looks like a winner.

Russell, I originally thought it was the motor too, but after I took it apart and tested it, I don't think so. I've now blown controllers on two totally different hub motors. I know how to blow the controller up-- it's just a lot of throttle from a stop with a nice lithium pack attached, ramping the current limit down would probably help (which is what I'll do to this controller when I have time to fix it). It's always just one of the FETs that goes so I can open it up and swap a FET in (I'm using one controller for parts, it's not financially worth it to reFETthe whole thing with a good IRF part, or at least it wasn't, I guess with all the wasted time now I should have done that after the first failure). Past half year I have been doing mucho mechanical work and not riding ebikes much so when I do get on one its so farking annoying to have the controller blow out yet again one block down the road. It's time for wind in my hair not a soldering iron in my hand!!!

Thanks for the pointers guys!

 

[fitek]

Man is this Ecitypower stuff for real? A throttle for $3? PAS sensor for $1? $79 hub motors (albeit only 200w or whatever, but certainly useful for some assist and non bicycle things).

 

[Russell]

Man is this Ecitypower stuff for real? A throttle for $3? PAS sensor for $1? $79 hub motors (albeit only 200w or whatever, but certainly useful for some assist and non bicycle things).

The shipping does add up...but yeah the stuff is pretty cheap if you order closer to the source and recognize you are assuming more risk than ordering from a dealer stateside. Also while they try to be helpful their customer support is woefully lacking due either to the lack of knowledge of what they are selling and/or the language difference. So far I’ve only purchased a cheap charger and the 9-FET controller from them, the charger came with a European AC plug which I changed and I had to figure out a couple of things on the controller but otherwise the items work fine. Other guys on this forum have purchased much more expensive batteries and battery chargers and reviews are mixed. Here's one of the longer threads;

http://endless-sphere.com/forums/viewtopic.php?f=14&t=9054&start=255

-R

 

[dscline]

Has anyone found a decent, affordable sensorless controller that can handle 72v?

 

[Affliction]

I was just about to say, I run a 5304 on that controller. I get them from High Tech Bikes. Its good for 36-48v 22 amps. I like em a lot, but wish they had a 30 amp model. But that doesn't mean you can't kill one.

The Wilderness Energy model is a 40 amp controller! It is instant start and sensorless.
For out of the box and no messing with it, it is a good bet.

 

[HTB_Terry]

We lowered the price of our controller to $70 and we warranty it will work at 48V but no higher. The caps are 63V and the mosfets are 60V so not a lot of margin with Li packs. They work for some customers but sometimes they blow at 48V. I'm currently investigating the cause so I can beef them up. The most common problems are the little sensor board and the mosfets, but not always. I am also testing the 72V 45A controller (sensorless) from Keywin. One died at 72V so not sure what the deal is. With a sensorless controller it's tough because if the controller looses sync (motor position), it doesn't know what mosfets to turn on. Seems there is little or no programming protection in these cases. The most likely scenario is that it turns on the wrong mosfets and it shorts out. I'm also looking at high back EMF combining with (adding to) the high pack voltages. There probably is no bullet proof sensorless controller on the market now. It would help to know exactly what the rider was doing when it blows. There's no consensus right now. More data points please: uphill/downhill, speed, voltage, accelerating/decelerating (slow/fast), pack full charge?, etc.

 

[dogman dan]

Yeah, I really trust all the specs on stuff in Wilderness Energy ad copy. I was so happy with my first WE kit, that went 20 miles at 20 mph on cheap sla's. :lol: More like 6 miles at best.

There may have been 40 or 50 amp controllers in some kits. The ones I have now, that I bought from Terry, are 22 amp I belive. I've not blown any of mine, but then, I don't do things like hit the throttle while slowly rolling backwards. A slight push forward, and half throttle for 1 second goes a long way to keep this controller happy.

 

[Russell]

Dogman,

You think some day you could try the Aotema controller with your Fusin geared motor? I'd like to find a sensorless controller that works well with a freewheeling motor since I found it frustrating using my dual-mode controller with them. At launch and any time the throttle is fully released the controller loses the position of the motor then must re-acquire it when the throttle is used again which can result in a "hammering" effect. Frankly I doubt any sensorless controller can completely cope with this however some may be better than others. Once I locked up the freewheel on my Bafang motor it does work great sensorless requiring only the slightest forward movement to provide a smooth launch from a stop.

On a related matter I found out from the Fusin board that their non-freewheeling gear assembly from their latest motors will be available for retrofit to the older freewheeling motors making regenerative braking possible.

-R

 

[Russell]

We lowered the price of our controller to $70 and we warranty it will work at 48V but no higher.

Terry,

Not a bad price.

Have you tried it with a Bafang?

-R

 

[dogman dan]

I keep meaning to try the fusin on the aotema controller, giving me more amps and 48v capability. But other things intrude. Lots of hot air balloon flying to do in the fall, and lately building another trombe wall on the house. One problem with three ebikes, they say ride me, not tinker with me. Actually doing most of my riding lately on the non motored bike. 60F days is perfect for pedaling.

 

[ekingsting]

On the Aotema ctrlr offered by Terry HTB - I just installed my new Turnigy Watt meter and went for a short test ride with 48v sla and I got 23.28 amps max , 1070 watts max. The resting voltage at 51.9v resulted in 45.67 min. volt at peak amps. So it can be verified that Terrys controller is indeed at least 22amp. at 48v.