Search results

Date Relevance Most replies

  1. jonescg

    jonescg's NEW electric racebike BUILD thread!

    Hi Dave, No, this bike is definitely a track only machine. Your knees are up around your ears, the seat is rock hard, it's got the turning circle of a novelty cheque, and no kickstand. It's actually not that hard to take a converted bike over the pits - you still follow NCOP14 like any other...
  2. jonescg

    jonescg's battery builds (historical reference - image heavy)

    Polycarbonate is great stuff - tough, non-conductive, and you can see shit about to happen, if it's going to happen :LOL:. I used screws, but there's no reason you couldn't use DCM to help weld the edges for a mostly watertight pack. I just taped up the sides with gaffa tape when it was wet at...
  3. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    The third image is of a 6p battery under construction. Sketch's battery actually.
  4. jonescg

    Question for pouch cell battery pack (im a full on idiot)

  5. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    This is a close up of how to stack the cells. Two facing one way, two facing the other way, two facing the first way, and so on. The buslinks will join one pair of positive tabs to the the next pair of negative tabs. Just study this assembly real carefully and see what I'm getting at. If...
  6. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    No, definitely used a BMS for this pack. It was a dyno pack for a motor-generator combination. Unfortunately the guys running it pushed the limits and pushed it a bit hard, but it served it's purpose. It wasn't tough, but it's the result of years of practice and iterative improvement.
  7. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    This battery was a 168s2p pack. So each block of cells was 42s2p. You can see from the front of the block that I've temporarily terminated one of the final terminals with a small rectangle of 2 mm copper with a single hole in it. This was later removed and linked to the next block of 42s2p by...
  8. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    No, a 30s2p pack is 60 cells in total. If each cell was 5 Ah, you now have a 10 Ah battery of ~100 V nominal.
  9. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    Look carefully at the cells. On a single stack of cells, there's pairs of cells facing one way, and then the other way. Fwd, Fwd, Back, Back, Fwd, Fwd, back, back... The tabs of both paralleled cells are folded towards each other with the punched hole overlapping above the screw hole.
  10. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    This is what I mean by 2p being a minimum:
  11. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    If you have two in parallel, the gap between then is sufficient for a soldered nut on the underside. Holepunch the tabs and fold them over the hole. Repeat for the next pair of cells, and screw a copper bus link down, spanning both. If you go 1p, the gap between cells is too small for a single...
  12. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    Thats basically it, yes.
  13. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    The screw termination system works best with 2 or more cells in parallel 👍
  14. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    If you must split the battery into two half packs, use one BMS, but you will need to run balance/sense wires to each cell and centralise the BMS somewhere. So if it's 30s2p, build two 15s2p batteries with a harness of wiring for each cell tap.
  15. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    CNC Water jet cutting. Only way to cut 2 mm copper without a fibre optic laser.
  16. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    You can, but the risk is the cells will wander out of balance, unless you have two BMSs. Generally we try to manage one string of cells of larger capacity than two separate strings in parallel.
  17. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    I had a big thread in the 'for sale' section but it was nuked in a clean out. You might find some more progress on these builds in other threads, but sadly the most detailed one is gone. I started here 15 years ago you know!
  18. jonescg

    jonescg's battery builds (historical reference - image heavy)

    Haha, yes, I've been known to do things barehanded before and remarkably never had the ring short stuff. I don't wear it any more :( But generally speaking use non-conductive benchtops, insulated tools and wear safety glasses whenever spotwelding, or working on the busbars. Always leave the...
  19. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    Buy the cells first, then design the PCB and build the enclosure. The cells vary from one batch to the next, so while they might claim to be 8 mm thick, they could be 8.2 mm. By the time you've stacked 24 of them cheek by jowl, you're looking at 5 mm bigger than you expected. Build a jig that...
  20. jonescg

    Question for pouch cell battery pack (im a full on idiot)

    As others have said, pouch cells are no better or worse than cylindrical or prismatics for longevity, however the one ace in the hole (copyright Zap Brannigan) they do have is the potential to discharge batchit crazy amps. This is because it's possible to have a meaty connection between all of...
  21. jonescg

    Tabless design cylindrical cells tests

    Those copper ends look beautiful, but do you have a photo of the aluminium end?
  22. jonescg

    BMS question

    For what it's worth, I installed one of these 16s LFP Seplos BMS 3.0 units on my home storage battery and it's working for that purpose. It does communicate with my Goodwe hybrid inverter but only when I select a Pylontech battery from the list. The Goodwe battery listings didn't work...
  23. jonescg

    Why do EV's have high voltage low amps?

    EV manufacturers using 800 V architecture are doing so for fast charging. 200 kW into a battery at 750 V is 266 A - manageable with 35 mm2 cables. Half the volts means twice the amps for the same power (hefty cables and connectors) or, accept half the charge rate. Other than charging, it carries...
  24. jonescg

    jonescg's NEW electric racebike BUILD thread!

    Sorry Frank, I missed this post from 5 months ago. 660 mm tall, 324 mm wide, 223 mm deep.
  25. jonescg

    Hybrids > EVs?

    We bought a 2020 Ioniq (38 kWh) in June 2020 - AUD$50,000 on the road. First and last new car we'll buy, but it's done 96,000 km and saved me at least $3500 in fuel a year. I've driven it to Esperance (700 km) in 9 hours. Fits more crap than an SUV and is super efficient. I regularly get under...
Back
Top