APL's V4 Cruiser Build.

[amberwolf]

I finally went into the CA advanced settings and accessed the shunt value, and found it to read 2.5 mOhms, which is way to much. (should be 1.0) The shunt is .75mv,.. so 100A/75 equals .75 mOhms. The CA only goes down to .763 mOhms in the settings, so I punched that in, and wound up with an extra 250w over zero on the meter.

You have to change the CA to High Range mode in the shunt settings to use lower values for shunts. It shifts the decimal places of a bunch of things to do this; there's a list in the CA manual you can refer to if you find the CA doesn't behave like it should after switching modes so that you can make sure it properly shifted all relevant settings.

 

[APL]

I tried using the high range mode, but don't really like the mental decimal conversion, and realized that both ranges were reading exactly twice the watts that the China meter was reading.

(Also found out how to zero the amps, so that the watts read 'zero' on the display screen at rest) At last! :thumb:

So I entered 2 X 75 mOhms, to 1.5, and now the CA and the other watt meter are reading the same. Go figure.
Since I don't have a calibrated watt drain of any quality at the moment, I'll have to compare it to a friends ebike, and/or buy a new CA and shunt at some point, to make sure that these meters are reading correct.

But at the moment I'm getting a momentary 4000w max at full throttle of the line, and about 600w at 31 mph.
(65v @ 60A = 3900w, so I'm probably close to popping the 60A fuse.)
Also reading almost twice the watt draw on the last video.

Next up, I'll give the battery a full charge and make a video of another 50 mph run so we can analyze the watt draw and see if it falls a bit more in line with the charts.

 

[mxlemming]

I tried using the high range mode, but don't really like the mental decimal conversion, and realized that both ranges were reading exactly twice the watts that the China meter was reading.

(Also found out how to zero the amps, so that the watts read 'zero' on the display screen at rest) At last! :thumb:

So I entered 2 X 75 mOhms, to 1.5, and now the CA and the other watt meter are reading the same. Go figure.
Since I don't have a calibrated watt drain of any quality at the moment, I'll have to compare it to a friends ebike, and/or buy a new CA and shunt at some point, to make sure that these meters are reading correct.

But at the moment I'm getting a momentary 4000w max at full throttle of the line, and about 600w at 31 mph.
(65v @ 60A = 3900w, so I'm probably close to popping the 60A fuse.)
Also reading almost twice the watt draw on the last video.

Next up, I'll give the battery a full charge and make a video of another 50 mph run so we can analyze the watt draw and see if it falls a bit more in line with the charts.

Good stuff. Much more credible numbers.

Fuses are rated for their long term withstand voltage. A 60A fuse will last basically forever at 60A, 30 second current is about 100A and several hundred amps to blow "instantly" (I'm getting deja vu here...).

I'm running a 50A fuse on my bike (20s4p) and regularly drawing 70+amps through it for short periods without issue.

 

[APL]

Thanks mxlemming, that's good stuff to know, I guess I don't know that much about fuses,.. I'm used to the little glass tube thingies
that seem to blow in an instant. Thanks for the charts!

Good to know that the 60A fuses can take a while longer and a bigger load before they go pop. Turns out that I've been momentarily
pushing mine past it's rating for quite a while now.

 

[APL]

Well I think I might finally have the CA calibrated and dialed in.

Another blunder on my part,.. turns out that the China watt meter has two shunt ranges, 50A/100A and needs to be consumer set. Guess a guy should read the instructions.

Went back and set the CA shunt to .765 mOhms, and the china meter to the 100A range, and now they're both reading the same, and presumably, correct watts. The two meters have different refreshing rates, so they don't always visually match up perfectly.
At any rate, all's well that ends well, and now it's a 9Kw burst cruiser that can max 50 mph. Sounds good. 8)

I made a video that shows the meters a little more clearly this time, and I'm seeing a 4700w max at 50mph, and about 3670w at 48mph on the consecutive runs, which is more in line with what's expected I think. The China meter also shows amps on the upper right, with a 119A peak, and I'm seeing a momentary max watt draw of 8962w at the launch.

https://www.youtube.com/watch?v=d6lHGPP8yBk

[youtube]d6lHGPP8yBk[/youtube]

Don't know what the deal is with the audio, doesn't seem to be working right.

Thanks to everyone for helping me get this straightened out, and showing me how far off the CA was,
I'm amazed,.. bottom line is calibrate your meters hey.

Next step I think, is to go back to the compression pack, fill it with the Samsung's, and see how it handles some bigger loads, but for now I think I'm just going to ride and enjoy the road for a while. :thumb:

 

[thundercamel]

I saw your new video today, and the bike looks quite strong! The power draw peaks once at an indicated speed of 17mph, and then again at 35mph. Do you know if your controller is using field weakening to increase the top speed?

I know you said your motor is a 4T Leaf @ 13.16Kv, 20 tooth at the motor 36 tooth at the wheel, 27" wheels, 16s battery for a full charge of 67.2 volts. The simulator suggests that field weakening must be working

Telephone poles are flying by at the rate of four to the seventh power
Well, I put two and two together, added twelve and carried the five
Come up with twenty two thousand telephone poles an hour

 

[fechter]

Those numbers are right in line with my Sur-ron at that speed. It seems to be quite power efficient. It's really great you can change the gearing to get it dialed in.

What's the highest speed you can still input pedal power?

 

[APL]

I saw your new video today, and the bike looks quite strong! The power draw peaks once at an indicated speed of 17mph, and then again at 35mph. Do you know if your controller is using field weakening to increase the top speed?

Thanks thundercamel, the controller has a three speed connector, and I put a MC-horn push button on the high speed option.
I push the button at about 30mph, :06 in the video,.. then there's a short lag, and starts to come on again at :07, then tapers off
at around 47 - 48mph. It will only hit the 50mph on the first run after a fresh charge, after that 48 is the best it will do.



This controller has turned out to be a great deal $$ after we did the 'divider' hack, and the high speed feature is on steroids because of that for some reason, and a real plus. A bit useless, but a lot of fun. The controller can be found for around $100. on the bay, if anyone wants to try they're luck. So far so good, and I don't feel anything getting hot,.. just one small spot on the heatsink about the same temp as my hand.

Makes me wonder how much more it will handle... :wink:

Sine wave controller 3000w 60-72v; https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=sine+wave+controller+3000w+60-72v&_sacat=0&LH_TitleDesc=0&_odkw=sine+wave+controller+60v+300w&_osacat=0&LH_PrefLoc=2

The throttle trouble I was having turned out to be the throttle itself, and after a replacement, I haven't had any problems.

 

[APL]

What's the highest speed you can still input pedal power?

The pedals are only good for about 10+mph depending on how fast you want to spin, just enough to say it's a bicycle, but any kind
of hill will make me want to get off and push. I thought about putting a small BB mid drive unit on it, but that might be a bit weird, and even more weight.

I'm working on a plan to build a more usable pedal ebike, concentrating more on light weight, that will actually make me healthier,
but might just settle for a rear hub motor on the old GT.

One thing that's been nagging me is that the bottom meter is showing peaks of 119A, slow refresh so maybe even more, but the BMS that I have is rated for 100A, shouldn't it limit to exactly 100 battery amps?

 

[fechter]

A slightly higher max pedal speed might be nice. Seems like you could change the gearing to do this. 10mph would be good if you had no power and were doing the "pedal of shame" back home.

The continuous rating for the BMS is generally heat limited. The over current trip point must be a bit higher or else it would have tripped and cut off. There are usually two over current settings, one for short circuit and one for over current that has a slower response. The specs for the BMS should list these, but they are not always accurate.

 

[APL]

I never really intended to pedal it, mostly for the lawyers, but it has got me home a few times. It has a set of super short cranks on it which doesn't help,.. I should try some longer ones and see what I can get away with for clearance, and your right, I should fool
around with the front gearing to try to optimize.

I'm trying to build the bike like a truck so that it wont brake down,.. but shit happens anyways.

A little off subject, but when I had the controller apart, I was wondering why they use thermal tape between the Fets and the heat sink, do they need to be electrically insulated? Wouldn't it be better to mount directly to the aluminum?

They also use a rubber strip between the hold down strap and fets, which seems like a thermal insulator to me, could I use a solid copper bar without the rubber for the hold down, to shed heat quicker?



Maybe it's all in vane,.. when they blow it's because they're overpowered and no amount of heat sinking will save it.

 

[fechter]

Yes, the FETs need to be isolated from the heat sink. The heatsink tabs on the FETs are connected to the drain terminal.
The rubber is there to give even compression on the FETs. Since there is no external heat sink on that side, improving the thermal conductivity won't help much. Unless your controller is running really hot, I wouldn't worry about the heat sinking much.

 

[APL]

Got it. Just curious, I don't remember building anything with multiple FETs, and a Google search wasn't very clear on the drain/tab
connection. Figured as much, but also know that they won't invest one more penny than they have to, so sometimes improvements are easy.

I'll leave well enough alone since there's no issues with heat, and it seems like it could take a lot more abuse. Thanks for the controller and BMS info! :thumb:

 

[flez1966]

APL did you ever find working software for this controller you modded, mine wasnt working as expected and during investigation decided to short its fets....
i was happy with the power but the top speed was 30mph then it would shut down. (mxus 3k turbo in a 19 motorbike wheel)

 

[APL]

Sorry for the late response flez1966, I need to check in more often.
I've been busy with some non-E bike projects the last few months.

No, I haven't found any software for it, in fact it's hard to find any info for it other than a few advertisements and a short wiring
video. I think this thread 'is' the spot for info so far. Perhaps if it was reposted in a better category more info could be gathered.
Kinda hard when the controller doesn't even have a proper name.

Shorted fets, ouch! How did that happen? I thought these were pretty darn robust.
30mph shutdown,.. BMS limit maybe, what is your battery volts and amps?
Have you used the high speed connection yet?

 

[electric_nz]

Great bike! I’ve been following this with interest as I’m looking at using one of those controllers with a Leaf motor.

What is the throttle response like from a stop? Many cheapo controllers seem to have a huge delay between moving the throttle and anything happening!

 

[E-HP]

Great bike! I’ve been following this with interest as I’m looking at using one of those controllers with a Leaf motor.

What is the throttle response like from a stop? Many cheapo controllers seem to have a huge delay between moving the throttle and anything happening!

If you look at his video above, you can judge for yourself. Using timestamps on the video, it looks like something around or under 4 second for 0-30mph, and still accelerating hard.

These clones seem to come with the current limits set to random values. Mine came set to 60A and I modded one to peak at 90A. APL's looks to be peaking at around 120A after modding. With 20S and the Leaf, even at 60A the throttle is too touchy to be safe for normal riding. There's a soft start jumper, but I wasn't able to get it to work, but the Cycle Analyst and a slow throttle ramp works well.

APL's 16S setup looks like a good way to go for better control off the line, without the downside of a twitchy throttle, and still having impressive acceleration.

 

[APL]

No problems with the throttle response electric_nz, go for it and let us know how it goes. The more info the better.

Thanks for the info E-HP, glad to hear you've had experience with one of these controllers too. I couldn't see any difference with the soft start jumper either.