New member taking the plunge with an eBay kit

B

BMboomer

10 mW
Joined
Sep 25, 2014
Messages
27
Hi everyone
This is my first post here, although I've been lurking for a while.
I,m a mature age bloke living on the Sunshine Coast Australia. I have enjoyed riding my bikes, just for recreation for many years, and I've recently got interested in ebikes after having a couple of test rides on some very nice ones at an excellent local specialist ebike shop.
I came away thinking that they were great fun, but way to expensive for the amount of use I would give one, particularly as I love my pedal power bikes, and still like to have a ride on one of those most days.
However, I came across this site, and started getting keen on the idea of building one. I don't want to spend heaps of money at this stage, just want to get something basic going, to see if I will use it much.
With that in mind, I was looking at kits on eBay & saw one that only had a few minutes to go, & still seemed quite cheap. I put a bid on it & ended up winning it.
It's a direct drive rear wheel kit, supposedly 36v 500w, the same as this one
http://m.ebay.com.au/itm/111454303644 .I ended up paying just under $150 shipped. There seems to be quite a few similar ones at 36v & 48v of various wattages, from this seller, and a couple of others, on eBay aus, & they say they ship from Sydney. I would probably have gone for a geared hub motor, but nothing cheap like this on eBay & suppliers like BMS battery, or GreenBikeKit, would want more than this one cost, just for shipping.
Anyway, I've done it now, so I'm looking forward to getting it delivered, & giving it a try. I'm thinking I'll power it with HK lipo, to keep things cheap (I've read up on the risks).
Now the questions start.
I know that 10s lipo is usually the go for a 36v system, but I'm wondering if I should go for 12s in case I want to upgrade to something 48v later?
I'm guessing that the motors on those similar kits are the same, and they just rate the voltage & wattage according to the controllers they put with them. Does that sound about right?
Would it be likely that the controller that comes with this could take the increased voltage of 12s lipo, or would I fry it?
Can those generic Chinese controllers be modded to take higher voltage?
What about the throttle with battery indicator, is that voltage dependant?
I' m guessing the motor is just an unbranded sensorless DD unit. Does that sound about right?
Does anyone know anything about those, or had any good/bad experiences with them, or with kits like this?
One other thing. It comes with PAS. I can't see anything to change the levels. Could I do that if I got some sort of LED or LCD display?
If it is just one level, does that mean it will just be full on assist when ever I pedal?
Hope I'm not asking too many noobie questions when I haven't even had the thing delivered yet. I expect I'll have a heap more when it arrives.
Cheers
 
BMboomer said:
I know that 10s lipo is usually the go for a 36v system, but I'm wondering if I should go for 12s in case I want to upgrade to something 48v later?
I'm guessing that the motors on those similar kits are the same, and they just rate the voltage & wattage according to the controllers they put with them. Does that sound about right?
Click to expand...

That's sort of right. Sometimes the motors are slightly different due to different windings of copper, which basically translates into slightly different speed characteristics of the motor. But that direct drive motor can take many different voltages. You could run 24V or 100V to the same motor (with different controllers) and the difference would just be the speed and power you get from that motor.

There's a chance that the controller can take higher voltage (without modification), but it is hard to say. It likely comes down to the capacitors in there. If they are 60V then you can give it 12s, but if they are 53V then you'll be pushing your luck. It's doable, but you could burn it a few miles down the road. Also your low voltage cutoff won't be correct for 12s, and as you read about the dangers of lipos, you know not to over-discharge them.

The good news is that there are many controllers that will work with that motor, and so you can pick up a 48V capable one from ebay for probably less than $40 shipped.

The battery indicator on the throttle is VERY voltage dependent, because its just a voltmeter. It will give you a general idea of if your pack is mostly full or mostly empty, but that's it. Changing the voltage of the pack from 36V renders that battery gauge useless. It doesn't matter though, because if you are using Lipo then you MUST have another means of monitoring battery voltage so you don't over-discharge the batteries. The throttle led's are not enough.

BMboomer said:
I' m guessing the motor is just an unbranded sensorless DD unit. Does that sound about right?
Click to expand...
I'm guessing it is sensored, not sensorless. Other than that, yea it's just a standard 28mm magnet 23 pole pair DD hub. Like a nine continent. They are very common motors and are good strong workhorses that can last for many years.

BMboomer said:
One other thing. It comes with PAS. I can't see anything to change the levels. Could I do that if I got some sort of LED or LCD display?
If it is just one level, does that mean it will just be full on assist when ever I pedal?
Click to expand...
This one I'm not positive on, but since it doesn't come with a display, I'm guessing it's just going to be one setting based on your pedal speed. The faster you pedal, the faster the motor will be powered. It's the simplest form of pedal assist that generally works fine on flat land but isn't well suited to hill climbing.

BMboomer said:
Hope I'm not asking too many noobie questions when I haven't even had the thing delivered yet. I expect I'll have a heap more when it arrives.
Cheers
Click to expand...

Ask away, that's how you learn!
 
You could just ignore the PAS..just not fit it.


They are not (generally ) proportional in any way..Without a 3speed switch it will simply give you maximum power when pedalling and nothing when you stop...Well actually nothing about one second after you stop pedalling..so a bit disconcerting.

Not so bad a low power levels/ voltages, but bloody useless, or dangerous once you start adding more power.


As previously mentioned, 10 s best if controller is definitely only good for '36' volts. but easy to find out. Just open it up when it arrives and look at the capacitors and FET's. Post pictures if you are not sure. Read the numbers on the FETS..could well be 3077's, which are absolute emac at 75volt, so best run lower than that. But also depends on the capacitors and the front end power stages that drop the battery voltages down to 5 volt. If you run it at too high a voltage, then you risk cooking the DC_DC convertor 'system' resistors at the front end.

But you are on a pretty safe bet that it will be good for 12 series..but open it up and check first.

If yo went 12 series, you could just not connect the voltmeter LED's on the throttle, or put a dropper resistor ion line to reduce the voltage going to it, ..You would have to experiment on that to see the best value that suits.
 
You can run any voltage on any motor as long as the controller will take it. The motor doesn't care. It will take all you can give it. The link you provided looks like a sensorless motor since I don't see a hall connector, but it may be a sensored motor. The motor rating is 500W. That means it should be able to run continuous at 500W. But unless you have unethical dealers, there will be a big difference in a 500W and 1000W rated motor. The 1000W rated motor can run continuous at 1000W. IOW's twice the power of a 500W motor. Controllers are rated the same way, even though you may be able to get 2000W or more out of a 500W controller, it's only rated for 500W continuous. Most 36V controllers should handle 12s lipo easily, and some may even work ok with 15s. The problem will be the lvc will be set to ~31V. Way too low for for even 10s lipo, so get a cheap volt meter to monitor pack voltage and re charge when pack voltage gets to 42V minimum.
 
I've never found a 36v controller that couldn't run on 12S, so that should be fine.

The throttle LEDs will be on all the time, so you can't use them. If you want to use Lipo, you need a wattmeter or voltmeter anyway to monitor them, so the throttle LEDs will be redundant.

The PAS is not adjustable. In the worst case, power will be proportional to pedal speed, which sounds sort of logical, but in practice, it's diabolical. There is a display that can multiplex the PAS and throttle signals that gives three levels of PAS. Details here. You can get that panel from a number of sources.

http://www.pedelecs.co.uk/forum/threads/con62-now-the-fun-bit.17005/
 
BMboomer said:
Hi everyone
This is my first post here, although I've been lurking for a while.
I,m a mature age bloke living on the Sunshine Coast Australia. I have enjoyed riding my bikes, just for recreation for many years, and I've recently got interested in ebikes after having a couple of test rides on some very nice ones at an excellent local specialist ebike shop.
I came away thinking that they were great fun, but way to expensive for the amount of use I would give one, particularly as I love my pedal power bikes, and still like to have a ride on one of those most days.
However, I came across this site, and started getting keen on the idea of building one. I don't want to spend heaps of money at this stage, just want to get something basic going, to see if I will use it much.


Cheers
Click to expand...
Cool have you considered a bike yet?
For entry level bike I would recommend checking out the bikes at bigw as they are surprising modern style bikes via diamondback, for example you can get this 650b 27.5 inch mountain bike with disc brakes for $260.

https://admin.bigw.com.au/sports-leisure/bikes-accessories/bikes/kids-bikes/bpnBIGW_0000000359933/diamondback-peak-650b-27-5-hardtail-mountain-bike.jsp;jsessionid=PTzaqVJ6eq8LqOcaeGcFbQ__.ncdlmorasp1101?bmUID=kyNSG3J

Actually most of the bigw bikes are not viewable online for some reason.
They also got a dual suspension 650b 27.5inch mountain bike with disc brakes for $300.
It's not like a lot of other entry bike BSO stores where it's merely 80s generation 26inch mountain bike with vbrakes...

Some one on this forum told me when I first joined you gotta build one to know what you really want and like .
 
Nice job on ebay, that guy will learn to have a shill bidder there at the end from now on.

As far as going to 48v (14s) later, it doesn't much matter. If you start with 10s, you need to add one more 4s pack for 48v.

If you start with 12s, then you need a 2 s pack later.

But depending on how you charge, two 6s packs may be the most convenient to break into sections to charge with a cheap 6 or 8s charger. I see no reasons to not just go straight to 12s. add a wattmeter, and a cellog 8 to the kit though, you need it to run hobby packs.

If the indicators on the handlebars don't burn out on 12s, they just become an on off indicator light. They never work well with lithium anyway. They are made for lead.
 
Thanks for all the helpfull replies. I,m feeling a bit better about giving the 12s batteries a go, and that the general feeling is that these sort of motors should be pretty robust and reliable.
If I got a 48v controller, would the lvc in that be OK for 12s lipo? The volt & watt meter sounds like a good idea, but it would be nice to have a working lvc as well. What about a BMS? Do most of you that use lipo, protect them with that.
As far as charging goes, I was thinking of an IMax b6.
Do you think it's worth paying more, for the genuine one, or are the copies OK?
Thanks for the bike suggestions, but I've all ready got a couple of 26" bikes that might be suitable. I,ve got a cheap BigW type Dunlop mountain bike which is quite sound, but heavy, but I,d rather use the GT Aggressor which I've had for about 13 years, and is still going strong. When I get the kit, I'll see which one will work best.
Cheers
 
BMboomer said:
If I got a 48v controller, would the lvc in that be OK for 12s lipo? The volt & watt meter sounds like a good idea, but it would be nice to have a working lvc as well.
Click to expand...

Probably not. Many different controllers have different default LVCs, but they are usually 42V or lower for most 48V controllers. Anyways, with lipo you really can't rely on your controller's LVC because the important thing is to make sure that not any single cell goes below a certain threshold. You really need a watt meter or at least a voltmeter at the minimum, but as dogman said a cell log would be best so you can track individual cell voltages.

BMboomer said:
What about a BMS? Do most of you that use lipo, protect them with that.
Click to expand...
This is another option that some (but not most) use for monitoring lipo. It takes most of the human factor out and cuts power when any cell drops below a certain threshold. It's a good method that some have used very effectively, but it takes some custom wiring to get it all set up. It's not a super beginner project but it's not too hard either.
 
Yes, the 42V LVC of most 48V controllers is perfect for a 12s lipo pack. I'd still recommend a voltmeter though as a fuel gauge. A cheap solution.
http://www.ebay.com/itm/DC-15-to-120V-Waterproof-Red-LED-Panel-Meter-DC-Digital-Voltmeter-Two-wire-WT7n-/400760815224
The imaxb6 is a 50W charger. It'll take ~9 hours to fully charge an empty 12s (444wh) 10ah pack. I wouldn't get anything less than a 300W 12s charger.
 
BMboomer said:
Thanks for the bike suggestions, but I've all ready got a couple of 26" bikes that might be suitable. I,ve got a cheap BigW type Dunlop mountain bike which is quite sound, but heavy, but I,d rather use the GT Aggressor which I've had for about 13 years, and is still going strong. When I get the kit, I'll see which one will work best.
Cheers
Click to expand...
OK no worries.
With those Dunlop and Repco bikes they are definitely of extreme minimal BSO entry level nature. Most are steel frames that appear to be deliberately designed for punishing buyers for not buying a nicer bike. They dont have drop out/screw holes for disc brake caliper etc and the v-brakes you get on those bikes seem to be be deliberately meant for slow stopping only. Seen some people complain one then net that they also can't pedal and turn the front wheel as it seems they deliberately made the front wheel too close to the pedals.
Obviously Diamondback were asked to provide entry level bikes for BigW but I would say that Diamondback would have to be secretly embarrassed to have their bikes sitting along side the dunlop and repco brands.
I would advice against going 48volt battery speed on the Dunlop/Repco bikes.
 
[/Just open it up when it arrives and look at the capacitors and FET's. Post pictures if you are not sure. Read the numbers on the FETS..could well be 3077's, which are absolute emac at 75volt, so best run lower than that. But also depends on the capacitors and the front end power stages that drop the battery voltages down to 5 volt. If you run it at too high a voltage, then you risk cooking the DC_DC convertor 'system' resistors at the front end.]

Hi folks
The kit arrived today, and I opened up the controller and took some photos.

IMG_20141002_193454.jpg

As you can see, the big caps are 63v. I'm wondering if those big resistors are what sets the LVC. There's a spare place for another one, I wonder if that's populated in a 48v controller.
There are 12 FET's. They have /RU7088R written on them. I don't know if that means anything to anyone.

IMG_20141002_193531.jpg

The motor is a sensored one, and I think it is a Golden motor. Here's a pic

IMG_20141002_194324.jpg

The motor is also ready for a disc brake, which was a bit of a surprise.

IMG_20141002_194244.jpg

I tested the spokes with a magnet, and they're not stainless as described in the listing, so that's a bit of a dissapointment.
So having seen the insides of the controller, would you be going for 12s or sticking with 10s? I was wondering if a couple of these Turnigy dlux auto checker balancers might be good, if I started out with 2 x 8000mAhr lipo packs in series.

http://www.hobbyking.com/hobbyking/store/__26136__Turnigy_dlux_Auto_Checker_2_6S_LiPo_Battery_Checker_and_Balancer.html

If I got those, would I leave them plugged into the balance wires pretty much all the time, (charging, running, & short to medium term storage)?
What are your thoughts on a good reliable charger, without spending too much, if the Imax B6 is not going to be powerfull enough at 50W?
Cheers for the help
Click to expand...
 
A quick google search of that FET brings up a dat sheet.
http://www.junyi-ic.com/upfiles/video/20121113155055.pdf

70 volt absolute max...so the 63 volts caps are the limiting factor.

so 12s will be just fine.

A larger picture of the who;le board..any numbers on it ? pic of the control chip...the MCU..pics of the area around the power resistors you mention, to show maybe the voltage regulator section. Cant see ...but it does not look like the Xie Chang style controllers we are familiar with on here, but more pics or tracing where the current flows out of those power resistors may help in working out what the voltage reg section is.

Try tracing back a 5volt output line all the way to a semiconductor component to see where the 5 volt is produced..that will be a start. I am guessing those two 3 pin " transistors " to the right of the power resistors are involved



Oh...pics only display if they are 80 pixels or less.
 
About your kit. No the big resistors aren't the LVC circuit. it will be one or more smd resistors, probably to the front of the board opposite the fets. The spokes are steel but not real good. i58-160mm. Some or most of them are probably lose. Tighten them up and they should be ok for the most part. Check the rim to make sure there's rim tape. If not, get some rim tape are you will likely have flats. DO NOT leave those balance boards plugged in all the time. They will drain your packs and ruin them if left plugged in long enough. 8ah of 12s lipo is 355wh. it will take a 50W charger 7 hours to charge them. 355/50.
 
wesnewell said:
About your kit. No the big caps aren't the LVC circuit. it will be one or more smd resistors, probably to the front of the board opposite the fets.
Click to expand...


Wes means the big resistors :wink:

I missed that reference when I read your post from my bed on the iphone without glasses at 1.30 in the morning :)

Those big resistors are voltage dropper resistors,
The cicruitry behind the controller, the main/master control unit (MCU) runs on 5 volts..the output to the throttle/e-btrakes/PAS etc also uses a 5v signal line.

Dropping from battery voltage to 5 volt is often a 2 (or 3? ) stage process.
A voltage dropper via resistors.
an intermediate 12ish volt level
then an accurate 5 volt derived from the 12 volt.

Those are the resistors that will get very hot if you increase the basttery voltage too much..but 12 series shoudl not be an issue. But keep an eye on them to see how hot they get.
One of my early 18 FET controllers, I ran at 100volts, it was fine for the FETs and the Capacitors, but the voltage dropper resistors coudl nto handle th epower they had to dissapate, , they got hot and melted the solder and fell off. Also a few SMD resistors also came off.

You will probably fidn those two (what look like) transistors to the right of the power resistors are incolved with the voltage regulation. I say " what lookk like transistors, as one may well be a 3 pin voltage regulator. The numbers on them may well tell us that.
 
Also , take a look at the back of the board.
hat row of 5 holes, labelled A3 F5 F6 etc..see if there are any other labels on the back. Like Tx Rx etc...maybe possible to re program the board with XPD. but also maybe not possible.
 
NeilP said:
wesnewell said:
About your kit. No the big caps aren't the LVC circuit. it will be one or more smd resistors, probably to the front of the board opposite the fets.
Click to expand...


Wes means the big resistors :wink:
Click to expand...
Yep. I sure did. Thanks, I fixed it.
 
Hi again
Thanks for your replies.
All your technical knowledge about my controller makes me realise how basic my understanding of electronics is. I took a few more pics, before I put it back in it's box, in case anyone's interested.
IMG_20141003_144212.jpg
IMG_20141003_144224.jpg


I thought I'd just drop the wheel into a frame, just to see how well it would spin, as cogging is one of my biggest concerns about DD motors, and those shop e-bikes I had a go on were geared.
I chose to try it on the Dunlop one, as that's just a spare bike, and it's the simplest one to fit this kit to, as it has seperate shifters and brake levers, and an old style BB that looked like I could fit the PAS.
Anyway it didn't just drop straight in as the chainstays were a bit tight and needed springing a bit. Also the washers were put on in the wrong order on the cable side, so that I had to take the pins out of the plastic hall connector in order to thread the wires through to turn them around.
I got it in there in the end, but the smallest sprocket is very close to the chain stay, so much so, that the chain will rub if I used that one.
Anyway it does cog, but it spins fairly well.
By the time I'd done all that, I was itching to see how it would spin with the motor, but I haven't got the batteries yet. Then I had the idea of seriesing up a couple of 18v 1.5Ahr li-ion power tool batteries, just to give it a try. So I did that. Funny thing was, I couldn't for the life of me get a reading off the batteries with my multimeter, but when connected to the kit, they register full on the throttle LED's. Maybe something to do with the BMS's.
Anyway the motor spins up great with the throttle. Nice and easy to regulate the speed with it too.
I thought I'd try the PAS, & that works fine as well. It seems to be dependent on turning the pedals at a fair speed before it cuts in, and then it spins the wheel up to full speed as long as the pedals keep going at that rate.
That was enough for last evening but now that I've come that far, I think I'll just put it all on properly in the morning with the e-brakes and everything and see if those little batteries will work for a bit on the road. Might give me a better idea of if 36v is going to be enough for me.
Cheers
 
that was a good deal for a direct drive motor. you can use up to 15S of lipo, 3x5S packs in series to power the controller. i would recommend adding another power resistor in series on the input of the controller to keep the voltage to the input of the 12V regulator down low enuff to keep it from being pulled up too high on the output of the reguglator.

i recommend removing the lipoly packs from the shrink wrap and assembling into a single battery by soldering the three pack together at the tabs on the ends after removing the big 10AWG wires.

then cut off the JST plug and sense wires and solder on the sense wires for a BMS to monitor and control the battery. by taking the lipoly out of the shrink wrap and putting it into a single pack under compression the pack will last longer and you can then use a bulk charger to charge the pack and balance it too.
 

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Neat work on the batteries. Never been that keen I am afraid. Not even got around to using a BMS. Thought about it a few times. Even built a Goodrum /TPPacks LVC HVC monitor board, but it was too big and clunky with all the JST plugs, so never used it..Not a BMS but at least it gave cell level cut out.

I just run my 20s4p nano tech pack with no BMS, and plug 4 x cell logs in tot he balance plugs when charging, with alarm set to 4.16..So as soon as an alarm goes off, i unplug the pack. A bi unbalanced now..4.13 to 4.16..need to do a balance soon.

Not yet found a BMS that I'd be happy to use..find space to fit. 20 series and 130 amp peaks.




Regarding the smallest sprocket and the chain..jsut spring the frame a bit more and use a spacer on the axle.

regarding the extra resistor. ...Measuring, calculations etc required to work that one out. Putting another resistor in the 'spare space' would just add a resistor in parallel..the opposite of what you need.
Looks like two 330 Ω resistors there..Orange Orange Brown colour code. so in parallel..165 Ω

http://www.hobby-hour.com/electronics/resistorcalculator.php

I guess you could just try a little higher and see what happens..see if you still get 12 vol ish at the 5 volt reg... Or at least whatever voltage you get at the moment, with the correct voltage.

Any one recognise the board? an older green Xie Chang ? EB2xx ? was it possible to do the (R12? ) LVC HVC resistor mod? on those boards.

Even if yo can not program the board, it may be possible to trick the MCU in to giving a different LVC by altering a resistor divider bridge.




With the controller powered up, you would first need to measure the voltage drop across those resistors and the voltage on the 'output side' Ideally also unsolder and measure the current through them , with max accessories fired
 
Hi guys
Thanks for all your thoughts on controller mods etc. Most of that stuff is a bit beyond me, at my inexperienced stage. Maybe I'll get into more complex experimentation later on, but I thought I'd just give you an update on my journey so far.
I got the whole kit fitted on my cheapy Dunlop bike (very cheap, I was given that bike), without too many dramas. I've only fixed everything with Velcro cable ties, as this is just a test bed just to try & see how it all goes together, & if it works.
IMG_20141006_073345.jpg
I still haven't got proper batteries, so I thought I'd see if the power tool batteries would be up to actually riding it on the road. I just had them taped together with cling film & duct tape with the solder sealed ends of the wires just poked into the battery terminals. I didn't hold out much hope for the batteries cos it doesn't take much to make them cut out if I use something heavy like a power saw, so I was thinking it would probably do that with a 500w hub motor on the end of them.
With that in mind, I left the PAS disconnected, so that I had better control, of when to use the motor with the throttle.
Anyway, set off for Mooloolaba Beach which is a trip I do regularly on my other bikes. It's about a 10km round trip, mostly flat, but a couple of bits where I have to stand up on the pedals if I am on my single speed (my favourite bike for that trip)
First thing I notice is that I need a lower gear to pedal comfortably on the flat.That old Dunlop is a bit of a dog to pedal at the best of times, but now it's noticeably heavier to pedal. No surprise there really.
The surprise was when I gave it a bit of throttle. It pulled strongly, and made the pedals as easy as could be. Same happened when I got to the bit of a hill where I would have been standing up on my single speed. Sailed up there in high gear, as if I was going downhill.
I used the throttle whenever the pedals felt the slightest bit uncomfortable, and arrived down Mooloolaba with all the battery gauge lights still on. No troubles with batteries cutting out at all.
IMG_20141006_091046.jpg
I had my Cycle droid app running, and I averaged 16.9kph, which is about the same as I do it on my single speed, but with no effort at all this time.
I had a cup of coffee, and reconnected the PAS for the trip home.
That's not as useful, because it cuts in when you pedal fairly fast which is not really when you need it, & then if you ease up on the pedals it keeps giving a big boost for a second or so. I felt like it was quite wasteful of my limited battery resources.
I gave it a bit of a speed test on a quiet straight road, and got 26kph, so I guess it's wound more for torque than speed, which is fine by me.
The batteries ran out at 8.5kms, so I had the last couple of km pedal only, just plodding in a lower gear, but all flat, so it was still pretty easy.
Freewheeling wasn't, too bad. On bits where I would usually freewheel, I reckon I would go about 80% as far.
One of the best things is how quiet it is.Can hardly hear it when the motor is going.
So on the whole, I am really pleased with it. I think it goes pretty much as good as a bought one.
When I got home I had to untape the batteries to charge them, which would be a bit of a pita to do often, so as I intend to perservere with them, until I get some proper ones, I made a little bracket to connect them, and they slide in & out just like they would in a power tool.
View attachment 4
IMG_20141006_072625.jpg
IMG_20141006_072716.jpg
View attachment 1
I like the look of these batteries, but they're out of stock at the Oz warehouse.

http://www.hobbyking.com/hobbyking/store/__65580__Multistar_High_Capacity_6S_8000mAh_Multi_Rotor_Lipo_Pack_AU_Warehouse_.html

Still not sure what to do about a charger, or monitoring, without letting the budget blow out too much.
So far I've got change out of $150, and had heaps of fun with it allready. I'm a lot more impressed with DD motors than I thought I would be.
Cheers to you all




.
 
I actually really like the pas. It also saves on battery power vs throttle. It gives a more bike feel than a motorcycle feel to the ride.

Found out that a 12 magnet pas is smoother and reacts better than the low count magnet pas
 
Whoa - did I see a torque arm at the rear?
 
Try one of these for the PAS

It gives 4 PAS power levels.

http://em3ev.com/store/index.php?route=product/product&path=41&product_id=104
 
The voltage increase to 48 volt would not be a big issue.

You will almost certainly be OK running at 48-50 volts as it is.

Easy enough to test out. Just open it up again, and feel those big resistors with it powered up for 5 or 10 minutes.

Then do the same at 48/50 volt.

If they are not burning up and noticeably hotter then I'd say you are pretty good to go.



Yes, checking voltages with basic voltmeter is best but if it works, well it works. Yes some risk but with all the controllers I've seen they all just work fine at 12s. It is not like you are massively overvolting

As for batteries, the hard case turnigy 4 cell packs were always best value. So 6 of those would do just fine, though look up the newer multistar lower C rating packs.

Nicer to have a balance charger that charges at 12s to
save stripping the pack to balance . Hyperion 1420 does up to 14s so ideal for you

Get 3 celllogs too, also from HK. I don't remember the last time I balanced my 20s pack. I just bulk charge with a BMS battery 2kW metal she'll charger, with the celllogs set to bleep the alarm tone when ANY cell reaches 4.16 volts.

Top of charge I see 4.13 to 4.16 volts, but after pulling 12 out of 20 Ah out the pack all cells are sitting at around 3.7

Get the cell logs that do real time logging (8S not the 8M model) and the first few rides, keep them logging and set the low voltage alarms to about 3.volt just to give yourself warning if you have a weak cell in any pack.


Oh yes, when buying Lipo from HK, ideally buy 10-15 % more packs than you need and then
Check the packs immediately you open the HK parcel. I video myself opening the box and putting the Celllog on each pack. That way if you do get a pack with a dead cell you have proof for HK. They give a refund but don't send replacements.


Then do charge/ discharge test with the Hyperion to see if any cells drop voltage sooner than others. Pick the best packs for the bike,- use the rest to rejuvenate old flash lights/ make better powerhool packs etc. Or if you bought enough packs, make a small capacity 'spare' pack for the bike. So if you need six 4s packs for your bike, order 9, so you are good for a 2 parallel pack whatever happens, or if all good a 3 p pack, or a 2 s and 1s 'nip down the road pack'
 
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