Search results

Date Relevance Most replies

  1. U

    BMS/battery trouble

    Thanks! As a matter of fact I already ordered and received this exact charger. What confused me was how inaccurate it seems to be - when measuring with a multimeter it's 0.1V off. And after searching the web I found no way to calibrate it, unlike the SkyRC version. Is this as expected? Maybe I...
  2. U

    Battery voltage drop overnight

    That's an excellent suggestion, I'll ask him if he's willing to do that! You are correct, thanks for pointing that out! I had forgotten to mention that upon opening the pack it became clear that the aliexpress seller had pulled one on me and given me cheaper cells than what the listing said -...
  3. U

    Battery voltage drop overnight

    The voltage on the bad group is dropping steadily, now it's at 3.93V while the others are at 4.09V. The BMS has been disconnected the whole time so it's not the problem. I found a repair shop in my country who can fix batteries. The seller gave me a couple of alternatives: 1) I can give him...
  4. U

    Battery voltage drop overnight

    That makes sense, the problematic group is the first/last one. But the charging cable had also fallen off that same group before(?) winter storage so it was probably way off the first couple of times I used the pack before I discovered the problem. I did, at least 48-ish. It does, ~0.1 vs...
  5. U

    Battery voltage drop overnight

    Oh crap!😱 Will store it outside tonight!
  6. U

    Battery voltage drop overnight

    The charger seems to stop (or go into extremely slow mide) when one group reaches 4.1V. The rest of the groups were at 4.09V, except the bad one which I later charged separately until it was 4.12V. But it didn’t stay there, it kept falling. Was nearly at 4.0V when I started charging it again...
  7. U

    Battery voltage drop overnight

    So you're suggestion would be to use the battery and see what happens and charge the low group separately if it is considerably lower than the others after a ride? I'm just a little worried that using the pack could somehow make matters worse :confused:
  8. U

    Battery voltage drop overnight

    I looks like it stops charging when a couple of the groups reach 4.1V, the rest stays at 4.09. The lagging group remained at 3.65V before I charged it manually with a single cell charger. Having said that, I never left it charging for more than 9-10 hours after the regular charger had "finished".
  9. U

    Battery voltage drop overnight

    Hi! I recently had a problem with my 72v 21ah triangle pack when a charging wire had fallen off one of the cell groups. After soldering it back on, it seems degraded. All the other groups can hold their voltage (or drops ~0.01V after charging), while the said cell group drops by a whopping 0.1V...
  10. U

    BMS/battery trouble

    My voltmeter battery was out, so the readings were way off. I have started to charge the low voltage cell group with a 18650 charger for dual cells, 4.2V. Feels like I’m charging a Tesla with an iPhone charger, it will take days😅 Where can I find a good charger for scenarios like this?
  11. U

    BMS/battery trouble

    Thank you very much for your help, sir! You were absolutely right, a wire had fallen off so I soldered it back on. I find poking around in the pack a little scary so I probably wouldn't have done it if it wasn't for your advice :) Now the 1-2 connector voltage is 3.8V and all the rest is...
  12. U

    BMS/battery trouble

    My 72V China battery says it's fully charged but stops working after a few minutes usage. I opened the pack and started measuring the small wires from the BMS connector to the battery. Here are the results: connector 1-2: 0V connector 2-3: 0V connector 1-3: 7.2V connector 3-4: 4.2V connector...
  13. U

    Tiny hub motor sucking the life out of my batteries.

    I will probably go the safe voltage route when I'm ready to throw the things away and find somewhere to deliver them. But if I can make one good battery with to bad ones, how long do I have once they start getting weak, is it a linear curve or are they degrading rapidly?
  14. U

    Tiny hub motor sucking the life out of my batteries.

    That's interesting! I won't be able to use the em3ev battery because it's 52V, but I do have an old li ion battery with the same problem as this one, but it's a different size, 12Ah instead of 20-ish. Could it still work? I may have to get a little creative in regards of placement since I don't...
  15. U

    Tiny hub motor sucking the life out of my batteries.

    So I got the wattmeter from from hobbyking and a new motor from aliexpress. It turns out that you were right @dogman dan, the battery seems to be getting tired. I also read about your battery fire now, so sorry to hear about it. My battery is very similar and bought around the same time. Thank...
  16. U

    Tiny hub motor sucking the life out of my batteries.

    I'm sure that's the best there is, but I am looking for something cheaper. Not because I'm cheap but because the bike is kind of illegal and could be confiscated by the cops at any time. Interesting zombie theory - I think I may have been abusing the battery a little bit with the 30 amps...
  17. U

    Tiny hub motor sucking the life out of my batteries.

    I get it:) Do you have any recommendations for my 72V system?
  18. U

    Tiny hub motor sucking the life out of my batteries.

    OK, so I went ahead and ordered a power meter from Hobby King https://hobbyking.com/en_us/turnigy-180a-watt-meter-and-power-analyzer.html. I will try the battery on my other bike as per your suggestion. Will try both bikes on the same route, starting fully charged and measure the voltage...
  19. U

    Tiny hub motor sucking the life out of my batteries.

    1) Unfortunately I don't have a CA or anything with a display so I would have to go oldschool with a wattmeter and a long wire to measure that. But what I don't understand is that the neither the wires, controller or motor feel hot. 2) The battery is a 48V 20Ah one, als bought from aliexpress...
  20. U

    Tiny hub motor sucking the life out of my batteries.

    Very similar to this...
  21. U

    Tiny hub motor sucking the life out of my batteries.

    So I have a 500W 48V brushless hub motor I bought from aliexpress. It's been working OKish for a couple of winters now, but it has always been a bit noisy and the range has been much shorter than that of my summer bike. At first I thought it was because of a weak battery, but after switching to...
  22. U

    Upgrading advice, 1000W 48V China kit

    Thanks for your suggestion, markz! The Leaf Motor kit looks nice, but I've decided to try to overvolt my current motor before I go for a full upgrade. Sadly, my controller is not pluggable, everything except the motor wires is soldered and shrink-tubed in place. I've looked for connectors to...
  23. U

    Upgrading advice, 1000W 48V China kit

    How about this controller: https://www.ebay.com/itm/36v-48v-60v-72v-40A-BT-PROGRAMMABLE-E-BIKE-BRUSHLESS-ELECTRIC-MOTOR-CONTROLLER/122976931745?hash=item1ca1ff0fa1:g:vBMAAOSwfdBal9eR With a powerful 72v battery? Tuning your controller from your phone sounds pretty darn sweet, if the...
  24. U

    Upgrading advice, 1000W 48V China kit

    Thanks Dan, your answers are always helpful! Safety > price, I have a kid in my flat so I need to be able to store/charge my batteries inside. Do you think my li-ions should stay outside? Variable controller, that's a good idea! Maybe I should look for one that is rated for 3kW. The Chinese...
  25. U

    Upgrading advice, 1000W 48V China kit

    Thank you for your response, amberwolf! I see some sellers are offering pre-built MXUS 3k wheels but considering the extra weight when also adding a much bigger battery I think you're right, the thing will be a monster and too heavy to carry 3 floors every day. About your "52v" option...
Back
Top