Search found 168 matches

by obcd
May 15 2021 8:49am
Forum: EBike Technical
Topic: Overvoltage protection
Replies: 14
Views: 444

Re: Overvoltage protection

Would a dual stepdown be an option? https://nl.aliexpress.com/item/4000777481955.html?spm=a2g0o.productlist.0.0.71cf7ea8HqUgNE&algo_pvid=null&algo_expid=null&btsid=0bb0624716210857290074984e41c6&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_ This module can convert 12 - 24...
by obcd
May 15 2021 8:22am
Forum: EBike Technical
Topic: Overvoltage protection
Replies: 14
Views: 444

Re: Overvoltage protection

The problem is you can't tell for sure it was overvoltage that killed your step down converter. They are rated for 15A peak and 10A continously with an output voltage set to 12V. In your case, the output voltage is set to 5V. A power consumption of 50W is 10 Amps. For 80 leds, this would mean 125mA ...
by obcd
May 09 2021 8:34am
Forum: EBike Technical
Topic: Overvoltage protection
Replies: 14
Views: 444

Re: Overvoltage protection

A battery has a low internal resistance, so during regen braking your voltage shouldn't increase much. If the BMS indeed shut off the battery due to overvoltage protection, it's a different story. On some controllers you can limit the maximum amount of regen current, but the voltage? Isolated step d...
by obcd
May 09 2021 7:55am
Forum: EBike Technical
Topic: What controller to use with a modified bionx motor?
Replies: 8
Views: 547

Re: What controller to use with a modified bionx motor?

Also note that some bionx systems use an 11S battery instead of the usual 10S or 13S. The motor is pressed together so it's not easy to disassemble. First you will need to unspoke it before you can open it. Another thing you have with those bionx systems is that the battery is not having any balance...
by obcd
May 06 2021 10:02am
Forum: EBike Technical
Topic: Heat from amps, but what of watts?
Replies: 36
Views: 1226

Re: Heat from amps, but what of watts?

ohms law is great, but power isn't always converted into heat. Take your e-bike motor. It actually converts power into a rotation. Take an antenna. It can make several 1000W dissapear in the sky as radio waves. Take a led. It converts power into light. Not all loads are resistive. Connect a dc volta...
by obcd
May 05 2021 3:30pm
Forum: EBike General Discussion
Topic: More newbie questions about USB ports and lights.
Replies: 11
Views: 342

Re: More newbie questions about USB ports and lights.

A led doesn't work on a voltage, it should be current driven. The led voltage is a minimum voltage you need before the led will start to conduct current. If you connect your led's directly to a 5V source without a current driver in between, the current will only be limited by the maximum that 5V sou...
by obcd
May 05 2021 5:00am
Forum: EBike Troubleshooting
Topic: Mystery electronic component - BBSHD Controller
Replies: 2
Views: 119

Re: Mystery electronic component - BBSHD Controller

It's a bit difficult with only the top view but it looks like an smd inductor. So it's basically a ferrite core (which is brittle) with some windings on it. You might be able to find replacements on electronic component webshops, but besides it's value they also have a maximum allowed current and an...
by obcd
May 05 2021 2:45am
Forum: EBike General Discussion
Topic: Aldi and kruitvat e-bike
Replies: 0
Views: 166

Aldi and kruitvat e-bike

Both Aldi and kruitvat are doing an action and selling a cheap front wheel e-bike for 800 euro's https://www.kruidvat.be/nl/formula-e-bike/p/5414011?country=BE The thing that sparked my attention was the fact they claim the front wheel motor has a 62NM torque. I usually see values around 30NM for a ...
by obcd
Mar 13 2021 8:45am
Forum: EBike Technical
Topic: step down converter with LM2596
Replies: 5
Views: 174

Re: step down converter with LM2596

An esp32 needs around 100mA average when wifi is working. So a linear regulator like the LM317HV would consume 3.5W. It might feed some bike lights as well, so a linear regulator isn't the solution I am after. I wasn't aware the LM2596HV existed. So maybe buying some cheap aliexpress modules and sim...
by obcd
Mar 12 2021 11:14am
Forum: EBike Technical
Topic: step down converter with LM2596
Replies: 5
Views: 174

step down converter with LM2596

Hi, I want to supply an esp32 module (5V) from my 36V ebike battery. An obvious solution is using a cheap aliexpress switching stepdown converter. However, most of them seem to use an LM2596 regulator and define 40V as upper input voltage limit. As we all know, a fully charged lithium battery can go...
by obcd
Dec 14 2020 9:38am
Forum: Motor Technology
Topic: Have I fried my controller?!
Replies: 1
Views: 200

Re: Have I fried my controller?!

Fuses blow for a reason. You didn't specify when it blows.
Does it happen under a load or even simply when you power the controller?

What motor is connected? What battery voltage are you using?
by obcd
Jun 17 2020 6:44am
Forum: Motor Technology
Topic: Grounding of Controller
Replies: 10
Views: 560

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: 610

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: 207

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: 6589
Views: 511208

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 light...
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: 699

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: 699

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: 28
Views: 1425

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: 385

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: 4504
Views: 454401

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: 28
Views: 1425

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: 1047

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: 240

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: 524

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...