Search found 158 matches

by obcd
Jun 17 2020 6:44am
Forum: Motor Technology
Topic: Grounding of Controller
Replies: 10
Views: 253

Re: Grounding of Controller

I wouldn't connect battery minus to motorcycle frame. If anything else touches frame once you did this, it will cause a short and damage to the electronics. The voltage you measure can come from capacitive coupling of some components mounted on a heatsink. A voltage meter hardly produces any current...
by obcd
May 29 2020 12:06pm
Forum: E-Vehicles General Discussion
Topic: Help
Replies: 6
Views: 251

Re: Help

As it says communication error, you would expect that the display isn't communicating with the motor controller anymore. I don't know the system details. Some use a seperate rx tx wire on ttl level. Some use linbus over one wire. Some use can. It can be an electrical problem between the motor contro...
by obcd
May 18 2020 6:29am
Forum: Battery Technology
Topic: Is my math correct?
Replies: 3
Views: 139

Re: Is my math correct?

Besides that, they normally don't take the full charged voltage as cell voltage but an average. For instance, a Li ion cell can usually be used safe between 3V and 4.15V. Normally, 3.6V is chosen as cell voltage. So a 36V battery has 10 cell groups in serie. When being fully charged, such a pack wil...
by obcd
May 12 2020 9:37am
Forum: Motor Technology
Topic: TSDZ2 mid drive with 860C, 850C or SW102 displays only -- Flexible OpenSource firmware (Casainho code only)
Replies: 5873
Views: 398831

Re: TSDZ2 mid drive with 860C, 850C or SW102 displays only -- Flexible OpenSource firmware (Casainho code only)

cowboy bikes have an option to switch the system in "off road" mode. It disables the 25km/h assist speed limit. They are sold as street legal pedelec's. I remember people complaining on a german forum that the gazelle lights are powered by the battery. According to the german law the lights must fun...
by obcd
Apr 30 2020 9:37am
Forum: E-Vehicles General Discussion
Topic: Relay or solid state switch to turn on my 90v DCDC for lights safely
Replies: 7
Views: 433

Re: Relay or solid state switch to turn on my 90v DCDC for lights safely

I was under the impression that the main purpose of gate drivers is to guarantee fast switch on / switch off times. A power fet heats up during it's transition from on to off and the other way around. The gate of a power mosfet is basically a capacitor that needs to be charged / discharged. Most mic...
by obcd
Apr 29 2020 11:47am
Forum: E-Vehicles General Discussion
Topic: Relay or solid state switch to turn on my 90v DCDC for lights safely
Replies: 7
Views: 433

Re: Relay or solid state switch to turn on my 90v DCDC for lights safely

5V usually is 2 low as gate voltage for such a power mosfet. They usually need 10 - 12V to become fully conductive. This might not matter much for a light as the current passing trough the fet will be low. Just measure the Drain Source voltage in it's on state to see if it's fully turned on. (Should...
by obcd
Apr 28 2020 7:32am
Forum: Battery Technology
Topic: Luna Charger dead after 10 uses.
Replies: 25
Views: 690

Re: Luna Charger dead after 10 uses.

I could be seeing this wrong on the pictures, but the small pcb has an smd transistor or regulator on it's right bottom corner.
It looks on the pictures like the left part of that component has vanished.
Maybe it's just the picture in which case you can ignore this writing.
by obcd
Apr 28 2020 7:21am
Forum: Motor Technology
Topic: Troubleshooting KT Motor controller opensource STM8 family
Replies: 2
Views: 274

Re: Troubleshooting KT Motor controller opensource STM8 family

Did you recompile the source 4 the correct type of microcontroller or did you just flash the binary? Creating open source firmware for your controller with a different microcontroller is likely a project on it's own. First, you will need to take the schematics of the kuteng the firmware is designed ...
by obcd
Apr 26 2020 10:12am
Forum: Motor Technology
Topic: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)
Replies: 4069
Views: 371029

Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Two things you could check: 1. What microcontroller is the controller using? 2. Does it measure the phase current. If it has a different microcontroller, this software can't be used. If it's not measuring phase current, it won't work either. Sometimes there is room for a phase measurement chip on th...
by obcd
Apr 23 2020 8:18am
Forum: Battery Technology
Topic: Luna Charger dead after 10 uses.
Replies: 25
Views: 690

Re: Luna Charger dead after 10 uses.

If the 15A fuse burned it's indeed likely the charger output got shorted and the battery voltage burned the fuse.
I assume you can measure battery voltage on the charge port?
I don't get why they don't prevent this as usually charge current isn't that high and all you need is a diode.
by obcd
Apr 23 2020 8:10am
Forum: Battery Technology
Topic: How long is it safe to use an ebike battery?
Replies: 21
Views: 774

Re: How long is it safe to use an ebike battery?

Before you start checking the battery, be aware that some bosch battery bms boards stop working if the cells or balance wires are disconnected. They don't restart working if you reconnect the cells. This is to prevent people from installing new cells in their batteries.
by obcd
Apr 13 2020 2:52pm
Forum: Battery Technology
Topic: Basic question??
Replies: 4
Views: 188

Re: Basic question??

They both will give you 3500mA * 3 = 10500mA The problem with the 3 serie strings in parallel is balancing. If you place 3 cells in parallel, you can see that entity as one cell with triple current capacity. A charger is connected to all the batteries in serie. If one of them decreases in capacity d...
by obcd
Apr 13 2020 8:15am
Forum: Battery Technology
Topic: DIY pack 18650 lithium safe
Replies: 9
Views: 422

Re: DIY pack 18650 lithium safe

The way batteries are normally assembled is that they create several groups of parallel cells (in your case 5) and put those groups in serie. (So that would mean 16 groups) If you don't want to burn your house (bad moment as corona regulations tell you to stay inside), you would choose a quality BMS...
by obcd
Apr 11 2020 3:00pm
Forum: Motor Technology
Topic: What lighting current from the KT controller?
Replies: 6
Views: 231

Re: What lighting current from the KT controller?

The 2 kuteng controllers I opened so far had a small separate pcb for the lighting. I assume they output battery voltage if you turn on the light. The switching fet is not so big. There are 2 signals coming from the microcontroller and going to that lighting pcb. It's a small pcb with not 2 many com...
by obcd
Apr 08 2020 7:23am
Forum: Battery Technology
Topic: DIY Arduino Battery Spot Welder et 48 v?
Replies: 41
Views: 985

Re: DIY Arduino Battery Spot Welder et 48 v?

A good spotwelder should furfill 3 parameters:

Controllable current.
Controllable pulse time.
Controllable pressure of electrodes.

The first 2 can be achieved with electronics. The third is another thing.
by obcd
Apr 06 2020 11:06am
Forum: Motor Technology
Topic: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)
Replies: 4069
Views: 371029

Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Disconnect the throttle plug and see if it behaves identical with the throttle disconnected.
Measure the voltage between the blue and black throttle wire with and without full throttle.
Check if there isn't a walk assist that somehow got enabled.
by obcd
Apr 06 2020 3:07am
Forum: Battery Technology
Topic: Bionx battery without BMS cell replacement
Replies: 2
Views: 115

Re: Bionx battery without BMS cell replacement

There is a BMS in the battery. It's just not blancing the cells. It has an undervoltage cutoff and overvoltage charging cutoff as well. It also measures the temperature of the cells. I read often about people using batteries without balancing. Some cells seem to deal with it better than others. Read...
by obcd
Apr 05 2020 4:30pm
Forum: Battery Technology
Topic: Bionx battery without BMS cell replacement
Replies: 2
Views: 115

Bionx battery without BMS cell replacement

I bought a cheap second hand bionx motor, display and battery. The battery cells are toast. The battery bms board is not having balance wires. It's an 11S 4P battery. Does it make a difference if you create 4 strings of 11 batteries and connect those in parallel compared to the normal method of havi...
by obcd
Apr 05 2020 4:18pm
Forum: Motor Technology
Topic: TSDZ2 mid drive with 860C, 850C or SW102 displays only -- Flexible OpenSource firmware (Casainho code only)
Replies: 5873
Views: 398831

Re: TSDZ2 mid drive with 860C, 850C or SW102 displays only -- Flexible OpenSource firmware (Casainho code only)

Isn't the original firmware protected against readout? If it's the case, we don't have it so you can't restore it.
by obcd
Apr 03 2020 7:20am
Forum: Battery Technology
Topic: What would happen in this scenario?
Replies: 10
Views: 304

Re: What would happen in this scenario?

If you cut one of the shunt resistors, you will half the controller current (assuming they are both the same) Only cutting one end of them is enough. No need to completely remove them. You need to check the controller mosfets maximum breakdown voltage (VDS max.) If your voltage is 2 high, they can g...
by obcd
Mar 31 2020 9:15am
Forum: Motor Technology
Topic: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)
Replies: 4069
Views: 371029

Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Some controllers have a 36V output for a headlight / backlight. It's usually a small additional pcb in the controller that has the switching fet for that output. Some controllers have an auto sensing of the hall sensor wires. In such case you usually have to disconnect a link for the auto detect (le...
by obcd
Mar 28 2020 5:21pm
Forum: Motor Technology
Topic: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)
Replies: 4069
Views: 371029

Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

If you use the stprog program, can you read the program memory from the microcontroller? There also is a feature that the controller isn't starting up if one of the brake inputs is activated. (It's starting up but not leaving it's initialising cycle.) Be very carefull. If you activate both the upper...
by obcd
Mar 24 2020 10:07am
Forum: Battery Technology
Topic: Bionx bike with another Battery
Replies: 5
Views: 647

Re: Bionx bike with another Battery

The board in the battery isn't just a BMS. It communicates with the display and the controller in the motor. I have some bionx stuff from a trek bike and the battery seems to be 11S 4P. I have no idea if the BMS board would come back to life when the correct voltage is applied again. If you don't ha...
by obcd
Mar 21 2020 9:43am
Forum: Motor Technology
Topic: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)
Replies: 4069
Views: 371029

Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

That pomp design is based upon a rubber tube that is pushed flat at 2 positions that move with the rotating motor. The product that will be pumped is desinfection hand gel, so it's not as liquid as water. Basically, the motor pushes the gel trough the tube. The motor has a gear box that reduces the ...