Search results

Date Relevance Most replies

  1. K

    Inductance question when connecting 2 batteries in parallel using ideal diodes

    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...
  2. K

    Using RC charger to measure wire resistance

    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...
  3. K

    DIY spotwelder with car battery + solenoid: some questions

    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...
  4. K

    10S4P with Samsung 29E vs 10S5P with Samsung 26H

    Hi, I'm about to buy a new battery pack for my Bosch ebike. My ebike is 36V with a 350W nominal motor. However afaik the motor can draw up to 540W peak. Not sure whether this is exact but I guess that max amperage should always be <18A anyway. I'm considering two different packs: - 10S4P made...
  5. K

    DIY Li-ion battery: first connect cells in series, then in parallel

    Hi, when building a Li-ion battery, it seems usual to first build groups of parallel cells and then connect these in series. Is it actually safe to do it conversely: first build groups of cells in series and then connect these groups in parallel? I understand that groups of cells connected in...
  6. K

    Any lipo checker that is not powered only from first cell?

    Hi, I'd like to use a basic lipo checker while riding my ebike to be warned in case of a low individual cell voltage condition. Unfortunately it seems most lipo checkers/alarms are powered from the first cell only and thus shouldn't be used for extended periods as they would cause cells to go...
  7. K

    (semi)-solderless design: Attaching cells with solder tags using brass bolts

    Hi, I'm investigating a semi-solderless design where 18650 cells are bought with soldering U tags (8mm x 0.15mm thick pure nickel) already spotwelded but these tags are then attached together to form small 2P groups using M2 or M3 brass bolts. The idea is then first to combine these 2P groups...
  8. K

    How long is it safe to use an ebike battery?

    Hi, I own a 350W Bosch E-bike with a 36V 10S4P 400Wh battery made out of Samsung 29E cells. This battery is now 7 years old and has powered the bike for about 30'000km. It still works perfectly although its capacity is lower than new and it sags a bit. The battery has been used lightly because...
  9. K

    Bosch gen1 balance simulator

    Hi, I would be interested in building a balance simulator for a Bosch gen1 ebike (model year 2011-2013). The purpose of this would be to allow using a no-name 36V battery on a Bosch ebike. The problem is that the Bosch BMS inside the battery communicates with the motor through CAN. Therefore it...
  10. K

    Parallelling 2 Li-ion batteries with different internal resistance

    Hi, my 36V ebike battery (Bosch) is 6 years old and has covered 25000km over that period. It still functions perfectly but the range has obviously dropped a little bit since new and I guess the internal resistance of that battery is pretty high by now. I'd be interested to use a new 36V battery...
  11. K

    Need help for using N-Mosfets to switch on either one battery or the other

    Hi, I'd like to add a second battery (36V Li-ion) to my ebike to increase its range. My goal is to use one battery at a time, not using both in parallel with e.g. ideal diodes or something. I'd like to keep it as simple and as safe as possible and just use a 2 way switch to choose which battery...
  12. K

    Using a non-Bosch battery on a Bosch (classic) ebike

    Hi, one guy on a german ebike forum (see https://www.pedelecforum.de/forum/index.php?threads/classic-andere-akkus-durch-umbau-der-original-platine-verwenden-anleitung.23236) posted a thread on how to use a non-Bosch battery with the Bosch (classic) ebike. The idea is to take the BMS from an old...
  13. K

    Choice of battery (Bosch S-pedelec)

    Hi, I’m riding a 2013 speed-pedelec (pedal assist up to 45km/h) that uses a Bosch mid-drive engine (first gen, also called classic+). The battery is the original one and is now 3 years old with 18500km on the clock, and I plan to renew it soon. As this system is proprietary, I have basically 3...
  14. K

    Which schottky diodes for parallel charging?

    Hi, I'd like to parallel charge two Li-ion batteries, one is the original 36V 11Ah of my ebike and the other will be a 36V 13Ah extender battery pack. For this I'll use the original charger of my ebike battery and add a Y cable with XT60 connectors to charge the extender at the same time. To...
  15. K

    Brass vs stainless steel for electrical bolts/nuts

    Hi, I'd like to use a second battery pack on my ebike and parallel it with the original battery using ideal diodes (http://re-voltage.eu/electronicsID80V2.html). Wires can be attached to these ideal diodes using crimp terminals (eyelet) with M3 bolts/nuts. Since these will be subject to some...
  16. K

    Which fuse/fuse holder for a 36V system?

    Hi, I'm about to build an extender battery for my Bosch mid-drive e-bike which works on 36V. I will use ideal diodes to connect the original battery and the extender battery in parallel and I also want to protect each battery with a 20A fuse. I have two questions regarding this fuse: 1) most...
Back
Top