ok. so my last controller died (the one that came originally with carrera) so bought a new one from amazon - Keenso electric bike controller for brushless motor. Also connected it to throttle. The issue is - when I push the throttle (even a little bit ) 1 to 2 seconds and the battery cuts out and what I understand gives the low voltage error(all lights blink fast) so connected it voltmeter. the throttling - voltage drops from 36V to around 33V and then suddenly to 28V and battery cuts out. if I connect to charger - it’s a steady 40V and I can throttle to max and it never cuts out. Any ideas? Thanks
Please help, battery keeps cutting out with new controller
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JES2020
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To me, that sounds like you have a bad battery. Extreme voltage sag points to a bad cell or cells, in the pack.
harryS
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How many amps is the new controller. You probably won't know the amperage rating of your battery, but how many AH is it?
At 36V, your battery is about half charged. Full charge is 42.0V, Your charger puts 40V to the controller. It would probably put out 42V with nothing attached (no load). So start by giving the battery a full charge, but I doubt it will help. Try it anyway. See how high it charges. Although 42.0 is full, a older battery will be unable to get that high.
I think that's happening is that what's happening is that your battery is old. When you ask for throttle, the voltage sags so much that either the BMS inside the battery shuts it off, or the lcd/controller sense a low voltage and shut off power., If it works with a full charge, it will go off again as the voltage drops toward halfway, or maybe even sooner.
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I asked about the controller amperage to assess how big it is. Same reason for asking about the battery's AH. Perhaps you bought too big of a controller for your battery.
At 36V, your battery is about half charged. Full charge is 42.0V, Your charger puts 40V to the controller. It would probably put out 42V with nothing attached (no load). So start by giving the battery a full charge, but I doubt it will help. Try it anyway. See how high it charges. Although 42.0 is full, a older battery will be unable to get that high.
I think that's happening is that what's happening is that your battery is old. When you ask for throttle, the voltage sags so much that either the BMS inside the battery shuts it off, or the lcd/controller sense a low voltage and shut off power., If it works with a full charge, it will go off again as the voltage drops toward halfway, or maybe even sooner.
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I asked about the controller amperage to assess how big it is. Same reason for asking about the battery's AH. Perhaps you bought too big of a controller for your battery.
JES2020
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Have you tried switching the controller to you missus's bike and test it that way?
You will have to test each component of the system and locate which one is faulty.
Looks like you have tested the battery, the controller would be the next suspect.
BTW , I did a quick search on your controller and it seems to have a pretty low approval rating on Amazon, so that adds to the controller possibly being the issue.
JES2020
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Pretty sure OP's battery is 36 v.
Ok - newby - never knew about P and C options. Fiddling around those seem to slowly resolve this issue but still not right.
this is my current setup:
P1 - 87, P2 - 6, P3 - 0 - P4 - 0, P5 - 15
C1 - 06, C2 - 0, C3 - 8, C4 - 0, C5 - 2, C6 - 3, C7 - 0, C8 - 1, C9 - 0, C10 - n, C11 - 0, C12 - 4, C13 - 0, C14 - 2
Any suggestions on whats wrong?
this is my current setup:
P1 - 87, P2 - 6, P3 - 0 - P4 - 0, P5 - 15
C1 - 06, C2 - 0, C3 - 8, C4 - 0, C5 - 2, C6 - 3, C7 - 0, C8 - 1, C9 - 0, C10 - n, C11 - 0, C12 - 4, C13 - 0, C14 - 2
Any suggestions on whats wrong?
JES2020
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Those settings have nothing to do with severe voltage sag.You can adjust at what point the controller will shut off at low voltage, that is to save the battery from damage.
A fully charged battery shouldn't hit low voltage shut off as quickly as you stated.
You can try setting the low voltage cutoff to a lower setting, but if it's saging to 28v on a 36 v battery, that's already set really low. It should cut off at around 30v.
Ok. I have another controller arriving today - will test on that. Though have to say - fiddling with the P and C settings made it run a lot longer. I was just wondering if the settings that I have are not trying to fire a lot more powerful motor and hence the cut off. Like I said - very new to this - have dealth with certain electrical engineering bits but nothing like this.
JES2020
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If you mistakenly installed a 48 v controller on a 36v battery, the controller would shut down at around 39 v. I doubt you would ever get a 28 v reading, but I suppose it's possible.
JES2020
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Okay, I think you will solve the problem with the new controller. Keep us informed.
harryS
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When a KT controller powers up, it will select either 36V or 48V, and that will set LVC at either 30V or 40V. Your C12 parameter can adjust this a little. The lowest LVC you can have , after powering up on a 36V battery is 28V. You get that with C12 =0. With your C12 of 4, LVC is 30V.
You have C5 =2, which is undefined on my LCD3, but it sets the maximum current. For an LCD8, a value of 2 means "One level slow start/ Maximum current value", whatever that means.
You have C5 =2, which is undefined on my LCD3, but it sets the maximum current. For an LCD8, a value of 2 means "One level slow start/ Maximum current value", whatever that means.
JES2020
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"One level slow start/ Maximum current value", whatever that means"
This controls the power at the start of pedaling and / or, the throttle power at start up( depending on other settings).
So one level is the lowest power level at start up.
Maximum current value allows full power after start up.
It's a safety feature and also prevents jerky PAS start ups.
That's only for KT controllers, not sure the OP's controller IS a KT.
harryS
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Looking at his P1-P5 settings, and C1-C14, those are KT controller parameters. Now if he would mention the max amp rating, it might clarify things.
I had some 36V4AH packs that used to run my 20A KT controllers when they were younger. AFter five years, freshly charged, a 15A surge would cause a 12V sag and shut them off. I retired them.
I had some 36V4AH packs that used to run my 20A KT controllers when they were younger. AFter five years, freshly charged, a 15A surge would cause a 12V sag and shut them off. I retired them.
JES2020
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I looks like a KT, but that doesn't really guarantee it is one...the manufacture certainly is different, it could be a knock off but I wouldn't assume it is a KT.
NOTE : OP, it would help if you listed the motor specs: wattage, amperage and volts. Max current , and accepted voltage of the the controller, also if you know if it is actually a rebranded KT controller. Controller brand is not all that important, because those parameters wouldn't solve your issue IMHO (but the parameters would likely serve different functions)
JES2020
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Some controllers start at 48 volts and ONLY and go up from there, so there is a possibility that the controller is wrong for this battery.
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