Sur-Ron - New Mid drive Bike

Finally built a case for my LED lights DC/DC converter. Milled from a piece of acrylic plastic. I installed it next to the sur-ron dc/dc converter because I removed the twist throttle device for a thumb throttle.

This wasn't an easy job and took me an embarrassingly long time to make. I wanted it to be very robust and waterproof. I added an on/off switch, but it will still turn on and off with the key switch if the DC/DC converter switch is left ON. If I'm not using my lights then I don't want to leave it on as it uses 4-5 watts on standby.

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I made my own connectors to connect to the stock connectors, so I wouldn't have to splice anything for the battery voltage.
This crimping tool worked great and made very good crimps.
http://toolaid.com/product/18910

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looks good offroader, its amazing how much time it takes to figure out how to retrofit stuff.

With your controller, does it do auto detect for all the motor settings? Does it list what settings it detected? I ask because my controller asks for the user to input the settings and i don't know what values to use for things like motor kv etcScreenshot (3).png
 
thoroughbred said:
looks good offroader, its amazing how much time it takes to figure out how to retrofit stuff.

With your controller, does it do auto detect for all the motor settings? Does it list what settings it detected? I ask because my controller asks for the user to input the settings and i don't know what values to use for things like motor kv
Click to expand...

The nuclear controller auto detects most of those things, it spins the motor and sets it up really well. I would have to look to see if it lists it, it probably does list everything.
 
Was out last night testing out my lights. Unfortunately it seems my power supply has issues as I can't draw more than 7 amps before it has a huge quick drop in voltage and eventually turns my lights off. I have to limit the lights power.

[youtube]lbc4kyduRfU[/youtube]
 
Offroader said:
Highest I could get the motor was 72C-74C. It mostly stayed around 65C-70C. This is with 88F outside air. This is also using 90 amps x battery voltage with a Nuclear 24 fet controller.

I checked the case temp with an infared thermometer, when the temp was 65C inside the motor measured by the temp probe, the case temp measured 57C.

Temperatures also do not spike quickly, even at full throttle and hill climbing.

Does anyone think these numbers are kind of too low? Even the motor case temp outside was 57C and only 8C cooler than inside at the windings?
Click to expand...

Sounds about right. It's winter here - so cooler ambient, around 15c - I struggle to get to get motor temps over 70c over 16km journey, 10-15 hard 500a launches - 60 km/h cruise, 85km/h peaks - 16.2kw power peak. Holds up remarkably well to big power.
 
Ohbse said:
Offroader said:
Highest I could get the motor was 72C-74C. It mostly stayed around 65C-70C. This is with 88F outside air. This is also using 90 amps x battery voltage with a Nuclear 24 fet controller.

I checked the case temp with an infared thermometer, when the temp was 65C inside the motor measured by the temp probe, the case temp measured 57C.

Temperatures also do not spike quickly, even at full throttle and hill climbing.

Does anyone think these numbers are kind of too low? Even the motor case temp outside was 57C and only 8C cooler than inside at the windings?
Click to expand...

Sounds about right. It's winter here - so cooler ambient, around 15c - I struggle to get to get motor temps over 70c over 16km journey, 10-15 hard 500a launches - 60 km/h cruise, 85km/h peaks - 16.2kw power peak. Holds up remarkably well to big power.
Click to expand...

im on the older firmware too... will be updating soon.
 
Any idea anyone?

The battery voltage (68 volts) going to the sur-ron DC/DC converter, that which I tapped into the wires, seems to voltage sag with very little load. These are 2 smaller wires and the 68 volts (battery voltage) goes on and off when you turn the sur-ron key.

Basically just the sur-ron dc/dc converter will drop the voltage from 58 volts to 48 volts just by connecting the sur-ron dc/dc converter and that draws less than 1 amp from the 68 volts wires.

I'm not sure how the battery voltage gets turned on and off to the sur-ron DC/DC converter when turning the key or bike ON,but there is something that seriously limits the current and you get huge voltage sag by trying to draw power from these wires.

Would anyone have an idea on what Sur-Ron could have done to limit the current going to the dc/dc converter and which causes huge voltage sag if trying to use these 68 volt wires?

Is this some kind of safety precaution they built in or is it just resistance in how the power gets sent when turning the key on/off?


I thought all along my DC/DC converter was the issue because I would never imagine that the high voltage battery input, which I probably only use 1.5 amps max, would be the issue. When I connect directly to the battery using alligator clips, I can power all my lights which draw 12.5 amps, with no issues.
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As far as I know, the battery voltage goes from the breaker to the key switch (via the small glass fuse) to the DC-DC. You might want to check the voltages on the ends of the glass fuse. You shouldn't be seeing that kind of drop. Something is getting hot somewhere that's not supposed to be or one of your measurement points is bad.
 
With further testing the issue comes from the negative wire and not the positive. I'm not sure where the negative wire connects to. I may just connect directly to the battery with the negative and keep the positive connected to the connector this way the key will turn on/off my 2nd dc/dc converter.

The negative wire is not controller by the switch.

Its hard to find out where these wires all run because I don't want to start ripping the bike apart.
 
I figured out the issue. The ground wire I used was actually the Positive 12volt wire.

I connected to the +67 volt wire and the +12 volt wire. I actually got voltage from this because there was a 12,500 ohm connection from +12 volts to ground. This was enough to power my DC/DC converter even though it was going through a 12,500 ohm resistance, hence the problems I was having.

I then connected to the proper ground wire and everything works. Wasted many hours and ripped my bike apart to figure this out.

The bikes DC/DC power supply has 3 wires and shares a ground for the battery voltage and +12 volts.
 
I'm not exactly sure where that negative connection is but I think it must be about 4" up from the main controller lug. There's a section covered in heat shrink there and I don't see anywhere else it might come out.

Glad you figured it out. The stock dc-dc seems to be pretty good but I'm not pushing it.
 
Hello guys, can anyone help me ?
I have a Sur-Ron X with now a BAC8000 installed on it, stock battery not BMS bypassed (for now - I would like to buy in some weeks/months a 72V), and just want to setup it correctly to have great power, but I am not very interested in top speed, I just want a very good torque. It work actually but not better than the X controller (and to say everything less good as the X controller), so something is wrong in the setup...

Can anyone give me the rights data I must enter for :
-> in motor setup
General Motor Current (Amps) :
Rater Motor Power (Race Mode Throlle Power) (Watts) :
Rated Motor Speed (RPM) :
Gear Ratio (N:1) :

-> In throttle setup
Throttle Full Voltage (Volts) :
Throttle Off Voltage (Volts) :
Throttle Fault Range (Volts) :

-> In Manufacturer Settings
Controller Output Current Rating (Amps) :
Controller Input Voltage Rating (Volts) :
Phase A Current Gain (Amps/Volts) :
Phase C Current Gian (amps/Volts) :

Thank you in advance for your help and please don't say me buy I better battery or made the BMS bypass, I just want to leave the stock battery for now and replace it after for a 72V. Thanks in advance for your HELP !
 
tolkaNo said:
Whats the max length shock that fits the stock linkage?

Will a 270mm eye to eye fit?
Click to expand...
Stock shock is 266.7mm so yes, you will be able to fit that shock.
 
Anyone change their rear shock spring to a 500lb rate,stock is 450.At 165lb Rider weight my spring is to soft and adding more pre comp is not a solution.Springs that fit are rare.Fox makes one but it’s 8.25 long and we need 7.6 long.
 
fechter said:
If you limit the battery amps to around 100A, the stock battery can handle it unless it's a really hot day.
Click to expand...

Define hot... summers here are almost always 105 f (40 c) lol

I’ve been running mine at 100A for a few months with my nucular, hasn’t burnt up YET. Running this hot and this hard should degrade the battery faster, right?
 
Where to get replacement battery:
My battery died,shows 37 percent on the battery but only 27v at the output.Where are replacement batteries available.Luna is out of stock.
 
sens_dep said:
fechter said:
If you limit the battery amps to around 100A, the stock battery can handle it unless it's a really hot day.
Click to expand...

Define hot... summers here are almost always 105 f (40 c) lol

I’ve been running mine at 100A for a few months with my nucular, hasn’t burnt up YET. Running this hot and this hard should degrade the battery faster, right?
Click to expand...

I'm not sure at what temperature the battery goes into shutdown. On a 100F day, just parking in the sun a long time will get it close.
All the battery experts say higher temperatures degrade the battery faster. Certainly storing at high ambient is not as good as storing at lower temps. But warmer batteries perform better, less sag and more usable capacity. I'm not really sure if discharging them while hot is worse than discharging them when they are cold. Too cold is bad also.
 
Kauaiguy said:
Where to get replacement battery:
My battery died,shows 37 percent on the battery but only 27v at the output.Where are replacement batteries available.Luna is out of stock.
Click to expand...
I got a new battery from the elecycle-aliexpress store, it shipped from so-cal in less than a week.
 
Kauai-
How many miles on your bike? First I've heard of the battery problems. I have had mine for almost three years now, 2,500 miles. Still get about 50 miles per charge.
 
My Bms is what went bad,it won’t charge or run the motor but on the battery rails I get 57v and 38 percent on the battery gauge.Luna wants me to send it to them for repair,but I live on a island in Hawaii so it’s more complicated to ship surface.About 1000 miles of narly off-road over 9 months.
 
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