itchynackers
100 kW
I finally received a working 4115 18 fet lyen controller that works. Anyone know what value I need to program into the cycle analyst for the "Rshunt"?
Thanks,
Adam
Thanks,
Adam
Shunt (Rshunt) value for 18 fet lyen controller?
- Thread starter itchynackers
- Start date
itchynackers
100 kW
Excellent. I'll try that.
Thanks.
Thanks.
number1cruncher
1 kW
I don't have an 18 FET controller, so my advice should be taken very loosely. However, with parts I bought from Lyen, I built a 9 FET controller. It had one 4 milliOhm shunt. Lyen had advised me before supplying the shunt that it could be 4-5 mOhm. Now on my 12 FET that Lyen built, except for the FETs, it has two shunts. So I would be curious how many are in the 18 FET you have. If 3, then the resistance would be around 1.4 mOhm(1.33333~mOhm), since they are paralleled. Good Luck! 
itchynackers
100 kW
1.4mohm doesn't seem to be working. The charger put in about 418wh (20.644ah), but the Cycle Analyst says I only used 281wh (14.200ah). Hmm.
number1cruncher
1 kW
acid said:
Itchy, If your's has 4 as well, this may be the better number. But it would be 1.08 mOhm OR .00108 Ohm.
However, if you do the math, it works out like this:
281/ 418 = .672249
1.4 / .6772249 = 2.082562
I would try 2.08 mOhm if 1.08 mOhm does not work. OR contact Lyen for the correct number...
grindz145
1 MW
4-5mohm is what Lyen told me. Measurement is the only way to get it dead on.
number1cruncher
1 kW
grindz145 said:
Is this for an 18 FET? That is what Lyen told me for a 9 FET that only had one shunt. If he gave you this number for an 18 FET, maybe he meant 4-5 mOhm per shunt?
But yeah, measurement would be the MOST accurate.
wasp
10 kW
- Joined
- Apr 3, 2008
- Messages
- 679
it's not 4-5 thats insanely off for a 18fet...
lyen told me start at 1.4
last night i refined mine to 1.285 and am getting close to my turnigy meter that is hooked up aswell
is nobody running a ca and 18fet lyen that has zeroed in on the shunt value?
oh well i'm 90% there now
lyen told me start at 1.4
last night i refined mine to 1.285 and am getting close to my turnigy meter that is hooked up aswell
is nobody running a ca and 18fet lyen that has zeroed in on the shunt value?
oh well i'm 90% there now
itchynackers
100 kW
Lyen messaged me and said 1.4mohm. I'm doing one more test to verify that isn't working, then I'll adjust.
Follow me here:
If one shunt is approximately 4.8mohm, then for a 12 fet with two shunts:
Resistance should be about R = 1/(1/4.8 + 1/4.8) = 2.4mohm (which is accurate for my 12 fet),
Then 3 shunts should be:
R = 1/(1/4.8 + 1/4.8 + 1/4.80) = 1.6mohm
And 4 should be 1.20mohm
Am I wrong in my theory?
Follow me here:
If one shunt is approximately 4.8mohm, then for a 12 fet with two shunts:
Resistance should be about R = 1/(1/4.8 + 1/4.8) = 2.4mohm (which is accurate for my 12 fet),
Then 3 shunts should be:
R = 1/(1/4.8 + 1/4.8 + 1/4.80) = 1.6mohm
And 4 should be 1.20mohm
Am I wrong in my theory?
itchynackers
100 kW
Next test at 1.4mohm setting:
Ran out 32.740ah out of the (5s 60ah) battery.
Put in 48.994ah while charging.
That is a similar ratio, so I'll have to try a new value.
Ran out 32.740ah out of the (5s 60ah) battery.
Put in 48.994ah while charging.
That is a similar ratio, so I'll have to try a new value.
number1cruncher
1 kW
itchynackers said:
That looks perfect! You can verify at this address: http://www.sengpielaudio.com/calculator-paralresist.htm
I plug 4.8 mOhm and 4.8 mOhm, then 4.8 and 2.4 and come out to 1.2.
Sorry about the controller Wasp. Hope all works itself out for you.
itchynackers
100 kW
Well, I tried 2.08mohm. That didn't work. Seems like I'm going the wrong direction.
Test Results:
6.490ah out
14.270 in
I think I'll try 1.2mohm next.
Test Results:
6.490ah out
14.270 in
I think I'll try 1.2mohm next.
itchynackers
100 kW
Wow, I hope I don't get a failure. It's taken me so long to get a working controller in my hands. Any idea what failed on it and why? What kind of current/voltage were you running etc..?
wasp
10 kW
- Joined
- Apr 3, 2008
- Messages
- 679
i changed my shunt value then reset my cadp then reset my turnigy then held the front brake and gunned it and poof...itchynackers said:
don't know what fried it shut everything down including the turnigy
the ca was set to 50amps and the controller to 80 and was running 10s2p
i had done this before with the 9x7 to get peak amp readings and never had a failure untill now
oh well good time for upgrades...just sucks that my backup controller is blown aswell and i'm ebikeless for a bit
itchynackers
100 kW
Hmm,
I would never think to try the braking to get peak amps, as I have the e-brakes hooked up. I like them. I get peak amps by feathering into the throttle within the first couple seconds. Seems more like a realistic method to me. I've been running 25s 12ah lipo on lyens 12 fet, and now the 18 fet with no ill effects, yet. Maybe your 10s battery is too low a voltage for the controller. I'm not sure how much damage low voltage could do to the controller, but I do know that I have a switch on my controllers for running lower voltage, and higher voltage.
I would never think to try the braking to get peak amps, as I have the e-brakes hooked up. I like them. I get peak amps by feathering into the throttle within the first couple seconds. Seems more like a realistic method to me. I've been running 25s 12ah lipo on lyens 12 fet, and now the 18 fet with no ill effects, yet. Maybe your 10s battery is too low a voltage for the controller. I'm not sure how much damage low voltage could do to the controller, but I do know that I have a switch on my controllers for running lower voltage, and higher voltage.
itchynackers
100 kW
Test Results at 1.2mohm:
11.750ah out
15.522ah in getting closer, so I'll lower it more:
Assuming I get about 91% efficiency from batteries, then:
11.750ah/.91 = 12.912ah into batteries
12.912ah/15.522ah = 0.83
0.83 * 1.2mohm = 1.00mohm, so I'll try that for my next test.
Is 1.00mohm for a lyen 18 fet shunt possible?
11.750ah out
15.522ah in getting closer, so I'll lower it more:
Assuming I get about 91% efficiency from batteries, then:
11.750ah/.91 = 12.912ah into batteries
12.912ah/15.522ah = 0.83
0.83 * 1.2mohm = 1.00mohm, so I'll try that for my next test.
Is 1.00mohm for a lyen 18 fet shunt possible?
itchynackers
100 kW
Test Results at 1.00mohm:
26.935ah out
29.728ah in
26.935ah/29.935ah = 90.6% battery efficiency...., seems reasonable. I think I found the shunt value.
26.935ah out
29.728ah in
26.935ah/29.935ah = 90.6% battery efficiency...., seems reasonable. I think I found the shunt value.
Paul_G
10 kW
itchynackers said:
The only way to set it is to put a DC amp probe on the battery as you run the bike on a stand full throttle and make the Rshunt value changes and run again and again till you find the setting till both read the same amps draw....the amp probe and the CA.
You can pick up a DC amp probe at Sears for $50.....warning...most amp probes will not read DC amps.
There is no other way that I know of to know if your battery holds what it should.
icecube57
10 MW
Yall are making this way harder than it should be. The ah counter on the charger would have been the perfect tool to dial in your shunt value.
If he has lithium it has damn near 100% charging efficiency. If you are only off by 10% then decrease the shunt value by 10% to increase the consumption showed by the CA. If his last test was at 1.0mohm he needs to drop down to 0.906 mohm to match his charger input.
If he has lithium it has damn near 100% charging efficiency. If you are only off by 10% then decrease the shunt value by 10% to increase the consumption showed by the CA. If his last test was at 1.0mohm he needs to drop down to 0.906 mohm to match his charger input.
