Backup Battery



  • @DrN3RD - you're right. I certainly don't want to come across like I'm jumping to conclusions - or bashing FM, that is not my intent. I'm a huge fan and wouldn't give up my boards for anything...however - being a geeky engineering type - this has definitely piqued my curiosity...





  • @DrN3RD I believe I have fount the battery manufacturer... and although at first glance it portrays itself as li-ion, further reading is indicative of a LiFePo system

    http://www.a123systems.com/lithium-ion-cells-26650-cylindrical-cell.htm



  • @DrN3RD So after digging some more. I have found these patent related statements

    For example, power supply xxx may include sixteen (16) A123 lithium iron phosphate batteries (e.g., size 26650). The batteries of power supply xxx may be arranged in a 16S1P



  • @D-Wave Probably the delta come from the fact that the batteries capacity can vary from 6600mah at the lower range to 6900mah for best ones, so I guess it's where the delta come from...



  • It does appear as if the term "Lithium Ion" is used to broadly describe several types of batteries, including LiFePo types, from what I read. I am in no way trying to bash or corner FM here by doing what I am doing. I am simply trying to fill a void they have left by not providing the ability to swap batteries. Yes, I realize I am on my own, and have voided my warranty by doing so, but My curiosity got the best of me. What does baffle me is that FM has chosen to NOT chime in and clear up some of these questions, as they have in many other forum posts. I do not think I have uncovered some type of cover up, and lets face it, we ALL would still be riding our OneWheels regardless of the paper specifications. However, some basic answers would be nice???



  • @Count I don't think any of us are bashing Future Motion, you've just uncovered something that appears to contradict a very important feature of the board that they advertise on their site. The company seems pretty honest, though, so I'm thinking what you're saying is probably correct, that the label on the battery packs isn't completely accurate.

    But I think we'd all like to hear from the company on this issue, just to clear it up.



  • @DrN3RD nice digging - looks like a high probability match...and the specs do say LiFePo.
    http://www.a123systems.com/lithium-iron-phosphate-battery.htm



  • @Tartopom - Thanks - I wasn't aware of the battery capacity range...I didn't see that in the manual - where did you find it?



  • @Count We are with you on this one my good sir.

    It is not bashing we want, but questions answered. And you have fulfilled many a void. :) My hat goes off to you sir



  • @D-Wave it's not in the manual, it's in the specs of the battery pack :) each lipo are not always at their top, so they guarantee a minimal capacity and a generaly observed max one, but we are all the time in the middle.



  • Im surprised they still have yet to answer on the battery issue.



  • Have you tried contacting them directly? They're probably too busy to read all the forum posts just in case someone wants their input. That's why they have support contacts.



  • @badcheese I don't expect them to read all of the forum threads, but you'd think they'd at least read the ones they've been tagged in, which I did. This would be a good fire to put out, pun intended.



  • Fire? Problem? I see no issue to address here. The battery works as advertised, correct?



  • @Angryviking It's not about how it's been advertised to WORK, it's about what it's been advertised to BE.

    There are significant differences between Lithium Ion and Lithium Iron Phosphate batteries (LiFePO4 are non-toxic and non-hazardous, have a lower discharge rate while idle, have a longer life, don't heat up while charging or while in use so are less likely to catch fire, basically just a much more modern energy source), so if the batteries in the Onewheel are not what they're advertised to be, that would be pretty serious. And illegal.



  • and with what Greck said, it would be a huge lawsuit to boot due to false advertising.



  • Might want to get your facts and terminology straight.

    LiFePO4 is a type of lithium ion. The iron/phosphate being the specific ion. The more unstable but powerful batterise people refer to as lithium ion is the LiCoO2. Both contains lithium and an ion. The difference is the type of ion. (Cobalt oxide)

    LiFePO4 has 3.65v/cell max charge. 16s battery of the one wheel charges to 16x3.65=58.4v (check your charger)

    If it were LiCoO2, max voltage per cell is 4.2v. 16s would yield 67.2v



  • @tomtnt Oh man... you're totally right! That's exactly the info we were hoping FM would jump in and give us, so thanks for clearing this up!

    I'm no battery expert, and I had been doing all my research on the subject through articles I found with a search for "Lithium Ion vs Lithium Iron Phosphate," and all of these seem to actually be comparing LiCoO2 to LiFePO4 (exactly as you said). But on the Wikipedia page for Lithium iron phosphate battery, it says:

    "The lithium iron phosphate a type of rechargeable battery, specifically a lithium-ion battery, which uses LiFePO4 as a cathode material."

    And it goes on to say just what you said, that it's more stable and safer than the LiCoO2 battery (which apparently is what most people are referring to when they say "Lithium-ion")

    https://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery



  • LiFePo4 has a nominal charge of 3.2V, which is lower than the other Lithium batteries.
    4x 3.2 = 12.8 V, so if it's 4 cells and labeled 12.8 V, then it's a LiFePo4.
    And you always charge batteries with a higher voltage than their nominal voltage.


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