Search results

Date Relevance Most replies

  1. H

    3 phase short, any potential issues?

    That makes a lot of sense. I will see if there are any problems while runnign later. I can still apply decent amount of force during my 3phase short braking..so I'm hoping it will be okay during normal riding.
  2. H

    3 phase short, any potential issues?

    I was playing around with a Q75 motor while lacing it up. I shorted the 3 motor phases (with a razor blade), and then forcefully turned the wheel. It was cool to feel how much mechanical resistance there was. However, I then turned the wheel harder/faster, and suddenly felt some "slippping"...
  3. H

    250W PAS build recommendation

    I noticed just now that Topbikekit.com is not secure (does not use https) Do people actually trust to send payment info, address, etc over to them this way? I saw on aliexpress/ebay, it costs significantly more, even after accounting for shipping costs.
  4. H

    250W PAS build recommendation

    Looking to build a 26" wheel, 250W PAS ebike for my girlfriend rim brake mountain bike. My rides are usually 1-2 hours at 17-20mph on paved/gravel/dirt roads. She can ride at about 10-12mph. This is just a bit too slow for me to enjoy. I tried my ebike with regen drag of ~100W, and that...
  5. H

    How hot do you let a downtube battery get? Is 45-50°C too hot for safety?

    I have a 10s7p Panasona GA battery pack from Ebikes.ca It was stated as 40A continuous/max BMS. The BMS allows for up to 150A though... (I change the bms shunt to test this, did not actually run 150A). During my 30 minute commute, I use it at 45A for about 1/5 of the time to keep up with...
  6. H

    2kW battery suggestion

    I apologize for all the typos, but you understood my intention for each of them :D Thanks for all the tips. For concrete power/capacity numbers: I used 650Wh for 14 miles one-way at 30-35mph cruising at ~50A. 25mph average moving speed. Slight headwind. Started at 42V, and hit 30V with...
  7. H

    2kW battery suggestion

    I'm looking for suggestions on batteries. I currently have a 10s7p Panasonic NCR18650GA, 40A rated, downtube battery (from ebikes.ca) My commute is 10 to 14 miles one-way. (25min - 40min) Elevation: Flat (less than 100m = 300ft of climbing either way) Wants and current limitations: 1)...
  8. H

    BMS limitation

    I had the controller and CA connected. Normally, turning off the battery via the switch, the voltage drops to near 0V in under a second. So seems like something was wrong that it was outputting 22V for a minute. That sounds nice, but a step up in effort to fit the sensor and op amp circuit...
  9. H

    BMS limitation

    Worked well, with a chisel tip :) Scary and doesn't make sense to me why advertised continuous would be the same as components' max ratings.. But now I know, haha. My next purchase will hopefully be more informed :) As for overcurrent threshold, I tested it a bit myself. I contacted Grin as...
  10. H

    BMS limitation

    I just realized that with 4 parallel 10mOhm resistors, at the stated 40A rating, if the resistors perfectly share the current, each will dissipate (10A)^2 * 10mOhm = 1W. They are 2512 sized resistors, so generally 1W rated? Makes sense to me now that they were getting so hot.. Seems to me...
  11. H

    BMS limitation

    Makes sense, I'll ask Grin Tech first. Seems it'd be a bit difficult to desolder since the copper planes on both sides would suck away much of the heat.
  12. H

    BMS limitation

    Oh I understand. Those seem to be wired correctly. Yes, they battery shuts off correctly when the switch is OFF, and also if the balance connector is disconnected. After I disconnected the balance connector and reconnected, I needed to force charge with the Cycle Satiator for the BMS to turn...
  13. H

    BMS limitation

    B- silkscreen connects through the FETS to both the discharge negative and charge port negative. What would P- connect to? I don't see that. All 6 FET's gates are 9.3V when the battery rocker switch is ON. When I turn to OFF, the gate voltages are approximately -25V, with one of them being -2V...
  14. H

    BMS limitation

    Thanks, yeah they are definitely not 10Ohm haha. I just ran my battery down to 28V, and cell voltages are 2.77 to 2.82. It stayed on even when voltage sagged to 27V. Is this a faulty BMS then?
  15. H

    BMS limitation

    I was initially going to just see when the BMS shuts off to protect itself, say 40A, or 42A. Then I'd just set my new controller to pull just under that amount (previously had a non-programmable 35A controller). I definitely don't want to unnecssarily abuse the parts.. I had asked Grin about...
  16. H

    BMS limitation

    I have a Hailong 36V 23Ah pack from Grin, that came with a 40A BMS. This is my first battery with a bms. https://ebikes.ca/b3623-lim-dt.html I wanted to see if I could push it higher than 40A for "short periods", and hopefully modify the most limiting components. What parts should I check for...
  17. H

    Power PCB for Lebowski Controller to be combined with Bobc's processor board

    I ended up increasing the gate resistors to 22Ohms and 100Ohms. Chose 22Ohms to reduce Vds spike to 100V with a 84V battery. Chose 100Ohms to reduce the Vgs bump I was seeing. They both seem like way larger values than the other recommended resistors :? I tried the measuring using the twisted...
  18. H

    Power PCB for Lebowski Controller to be combined with Bobc's processor board

    Is it 50mA idle or while running? I'm getting much higher while running. With a 40V battery, the buck converter was getting a bit hot, 50~60C, without being enclosed in a box. So I replaced my wire short with a 1/2W 100 ohm resistor. Idle: 5.6V -> 56mA -> 0.31W However, after running a bit, I...
  19. H

    Another SMD lebowski PCB

    Ah, yes, I understand the "setup" press to save. Thanks. Edit: Oh. Manual says 19, but schematic is 38. I'm pretty new so don't know when that might have changed..
  20. H

    Power PCB for Lebowski Controller to be combined with Bobc's processor board

    I built this board up with using IRF100P218 mosfets since they had really low Rdson (1.28mOhm). The datasheet values looked similar to IRFP4468, except for a ~100ns faster rise and fall time. IRF100P218, IRFP4468 360nC, 330nC Total gate charge 370nC, 280nC Reverse recovery charge 60ns, 52ns...
  21. H

    Another SMD lebowski PCB

    Oh, I just closed RESET with a jumper. Then closed SETUP with a jumper. I didn't try releasing. Changed the TTL-USB setup so "invert tx, invert rx" are not checked. (Edit: stopped working after first round of setup. Changed to "invert" and working again.) Close RESET. Close SETUP. Release...
  22. H

    Another SMD lebowski PCB

    I finished soldering the brain board, but am having issues with RS232. I programmed the DSPIC through MPLAB X IDE using the programming header. Using a FTDI TTL-USB from Grin for RS232; tried both normal and inverted TTL signals by reprogramming the EEPROM. Checked that it worked with a...
  23. H

    Another SMD lebowski PCB

    Thanks! Going to build one up soon :)
  24. H

    Another SMD lebowski PCB

    If I understand correctly, the controller can talk with most RS232 signals, given they accept 0V-5V. As my laptop doesn't have RS232, would this be the most straightforward way, using a TTL-USB that allows for inverting both RX and TX, like this...
  25. H

    Another SMD lebowski PCB

    Right, RS232 can go down to -15V, and requires at least -3V for logic high. What I'm wondering is why the signals are called RS232 in the schematic. They look to me like just 0 to 5V signals, albeit inverted with NPN inverters.
Back
Top