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Just one battery for the Propeller. — Parallax Forums

Just one battery for the Propeller.

LoopyBytelooseLoopyByteloose Posts: 12,537
edited 2012-06-15 06:29 in General Discussion
You have 10Ah at 3.2V. What more could you want? If you need to jump to 5V for some devices, Polou has tiny boards.

http://www.youtube.com/watch?v=DWMFizC3H7k&feature=related

Comments

  • Mark_TMark_T Posts: 1,981
    edited 2012-06-14 03:43
    What more? A solar panel to keep it charged? - for 8 cogs flat out it would last 5 days, enough for most cloudy weather systems(!)
  • piguy101piguy101 Posts: 248
    edited 2012-06-14 09:57
    I couldn't tell, is it rechargeable?
  • xanaduxanadu Posts: 3,347
    edited 2012-06-14 10:29
    piguy101 wrote: »
    I couldn't tell, is it rechargeable?

    Yes, looks to be LiFePO4 :)
  • Mark_TMark_T Posts: 1,981
    edited 2012-06-14 11:31
    xanadu wrote: »
    Yes, looks to be LiFePO4 :)

    3.2V gives the game away that its a LiFePO4 - a traction battery cell I suspect. No one makes disposable batteries that big anyway AFAIK.
  • GadgetmanGadgetman Posts: 2,436
    edited 2012-06-14 13:42
    Trust me, disposable batteries can be much bigger...

    Take a look at the 'PP-Series' cells...
    http://en.wikipedia.org/wiki/List_of_battery_sizes#PP_series
    Most of those are uncommon or no longer in use, but some still exist.

    My uncle used similar batteries in the electric fences on his farm. Takes a lot of power to deliver 5000V pulses a whole summer... (Add 'training pulses' of 8000V, or the ability to burn off grasses that touches the wire, too, to get a better idea of what is needed)
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2012-06-15 06:29
    These LIFePO4 cells are serious capacity at 10AH. Charging may require some research and I am constantly seeing people confuse the 3.2-3V LiFePO4 with LiMO2 which is a 3.6-7 volt battery.

    There are real hazards in confusing the two.
    Running these at excessively high voltage may cause a fire
    Running these at excessively low voltage may short circuit the battery and cause a fire the next time you try to charge it.
    And there is a maximum safe temperature which is a bit higher for LiFePO4.

    The nicest thing about LiFePO4 is that it is least toxic of all the Lithium batteries.

    For LiFePO4 do NOT use voltage above 3.9V for charging - the LiMO2 can go to a higher 4.25V
    For LiFePO4 do NOT use voltage below 2.8V for charging - the LiMO2 may only go to 3.00V
    For LiFePO4 do NOT go over 60 degrees centigrade - the LiMO2 may only go to 50 degrees centigrade

    And above all else, consider these only guidelines in lieu of other facts provided by the manufacturer. But be aware that a lot of vendors on line are claiming to sell 3.7volt LiFePO4 when that is NOT chemically possible.

    I try to get good information only, but I fear that inspired bloggers and rather uninformed sellers are very fuzzy on these details.
    Read Wikipeida for Lithium Ion and Lithium Fe PO4 cells before you believe too much from others.
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