Recent content by kilou

Any possibility wire length inductance (or voltage ripples) increases when using diodes or is it unrelated? It seems to me the current flowing through the whole battery wire would be "trapped" in a smaller portion, between the controller and the diode, when the motor shuts off...

I don't have the skills to read such complex diagram unfortunately. However, it seems wire inductance can still cause issue. Here is what I came across: "Adding wire length (inductance) in battery to controller wiring is very bad for the controller. It causes increased ripple in the capacitor...

The bike has no regen and it's not a direct drive. It's a mid drive motor with a torque sensor. This is probably why the BMS does not allow charging through the discharge leads. So without regen and no direct drive, does it mean it's a safe setup? Is a zener clamp still required? Where would...

No the fat wires are not coiled. Actually they are standard wires (same gauge as the other wires, AWG14) and are just fat for the purpose of illustration (section between controller and diodes). However the motor is coiled and I don't know how back EMF when the motor is turned off is passed...

Hi, I'm interesting in connecting 2 36V Li-ion ebike batteries in parallel using ideal diodes (e.g. mosfets) for reverse current protection. I know that (in principle) ideal diodes are not needed if the two batteries are connected with the same state of charge. However I have to use diodes in...

Thanks for your input! The power supply is going to be a car battery but I don't know if it this will provide "clean" DC as the battery is going to be basically shorted (using a heavy duty contactor solenoid) to make the spotwelds. The current spike should only last about 20 milliseconds or so...

The purpose of measuring the resistance of the AWG5 cable is to then use that cable as a shunt resistor to measure very large DC currents (e.g 500-1000A over few milliseconds) in a DIY battery spotwelder. The sense wires that will probe the voltage drop across the AWG5 cable will likely have to...

Yes my Icharger 3010B also has a hot wire foam cutter option and actually I thought about using it initially. The charger's documentation mentions that you need to set both voltage and max amperage for this mode and I (stupidly) thought I'd need the actual current to be fixed rather than the max...

Hi, I'd like to measure the resistance of a AWG5 wire over a distance of 50cm. I know that I may calculate a theoretical value by considering the ohm per km for such cable (about 1.1 Ohm/km) but I'd like something a bit more precise by sending a constant DC current through the wire a measure...

Hi, I'm only interested in welding 0.2mm thick pure nickel (possibly slotted) ribbons onto 18650 or 21700 cells. No copper/nickel sandwich method needed in my application.

Hi, I'm interested in building a cheap DIY spotwelder using a 12V lead-acid car battery, a heavy duty contactor (Tyco EV200 rated at 500A continuous, max 650A make current to avoid contact welding but break current could be up to 2000A) and controlling the timing with an Arduino board. My...

Great, thanks! I didn't know you were using 1mm thick magnets. Thought it would require at least 3mm to provide sufficient pull. But that's great to know that 1mm is enough (hope it's still good with your 0.1mm thick copper plate). Do you also use 1mm thick magnets for 21700 cells? Regarding...

Really interested by your approach to a solderless pack! I'd just have some questions on things I may have missed in the thread: - You're using 7.5mm diameter magnets on 21700 cells, right? Could you precise what's the thickness of the magnets? Why not 10mm diameter magnets on 21700 cells? -...

@goatman Great tests! Did you test the temperatures with the PlastiDip or without it? Also, what do you think about covering the vent holes on the positive terminal with PlastiDip? Is this not something to worry about?

See here: https://www.e-bike-vision.de/product/powerpack-for-bosch-classic/en In fact the 468Wh pack has Samsung 26J cells (not 26H) but AFAIK the characteristics are the same (e.g. max 5.2A discharge as well)