Results 1 to 7 of 7

Thread: Lion vs LiPo? Which better, or are they just different?

  1. #1

    Default Lion vs LiPo? Which better, or are they just different?

    I was wondering why radio controlled cars and planes etc, and mobile phones use Lithium Polymer batteries, whereas flashlights use lithium ion?
    How come power tools eg battery operated drills don't use Lithium Polymer?
    How are the two types different, and which is better, if any?
    Last edited by peterharvey73; 11-30-2012 at 02:13 PM.

  2. #2
    Join Date
    Dec 2011
    Northern Europe

    Default Re: Lion vs LiPo? Which better, or just different?

    Li-polymer are lighter and can provide very high currents, but they don't have too long cycle life, they have to be used with very big care, and they're not very safe.
    Lithium-Ions, on the other hand, can't provide so much current and are heavier (for same stored energy), but they are much safer.

  3. #3

    Default Re: Lion vs LiPo? Which better, or just different?

    I just found out that:
    Lithium is the lightest metal.
    Lithium also has the highest electric potential - meaning the highest potential voltage?

    Lithium ion is:
    Higher in energy density.
    Cheaper to manufacture.
    More rigid in shapes and styles.
    More internal resistance, for slower discharging, and lower amperages.
    Has greater aging, even if not used for 1 year.
    More explosive, so requires an IC circuit.

    Lithium polymer is:
    Moulderble, and flatter shapes.
    Less internal resistance for faster discharging and higher amperages, at up to 65C continuously, or 135C in bursts!!!
    By comparison, a typical RCR chemistry 18650 can only discharge at up to 5.8 amps.
    While an IMR chemistry 18650 at 2000 mAH will discharge at up to 10 amps, though an IMR chemistry 18650 at a puny 1600 mAH can discharge at up to 15C, but for the diminished capacity.
    Has less self aging, even if not used.
    Less explosive, so no IC circuit required.
    Less energy density.
    Expensive to manufacture.

    Thus, LiPo is used in radio controlled cars for their lighter weight and faster discharge rates, for massive amperages, for more power.
    LiPo is used in mobile phones especially for their flatter shape, and their lighter weight.
    While Lion is used in flashlights for their greater energy density for longer run times.

    Is that right?
    The safety business seems to be opposite to what Shadowww posted???
    Last edited by peterharvey73; 11-30-2012 at 02:37 PM.

  4. #4

    Default Re: Lion vs LiPo? Which better, or are they just different?

    Well, LiPos have a soft pouch, so they might not explode as violently. I'd still argue for protection circuit for both though.

    The round Li-Ions have been favoured by flashlight enthusiasts because it's easier/cheaper to produce a tube-like flashlight out of aluminium, and we want a metal for heat dissipation with our high power LEDs. For low power stuff, arbitrary plastic shapes are fine, but there we also don't need high power, and the aim is usually cheapness, so both Li-Ion and Li-Po are absent from that.

    Someone else here once said that it costs alot more to setup a cylindrical Li-Ion factory than to setup a Li-Po factory, so there are many Li-Po manufacturers out there. This has resulted in wide availability and selection of LiPo batteries offered to the hobbyists that use alot of them, RC.

    Some people say that LiPos are more dangerous. Whether that's true, or just a "urban myth" because of LiPos from newly started small Li-Po factory not quite being up to quality, is another question.. I'd definitely use a protection circuit of some sort. In the RC world, there's, I think, maybe 3 different strategies used. Cheapest, use a wristwatch and voltmeter. Set your watch to countdown from 5 minutes. Start it when you take off in your heli or airplane or similar. Land when your watch goes off. Check voltage, if it's very high still, you can increase your flight time for next flight. If it got a bit low, decrease. For $5 extra you can get a buzzer to mount on your RC model, the buzzer goes off at a certain voltage threshold, and you know it's time to land/park/etc... Then we have more advanced stuff, like speed controllers (sits between battery and motor) with programmable cutoffs. When battery voltage drops below a certain threshold, motor power is either cut entirely, or reduced before getting cut. The radio receiver, and the servos are powered "forever", so you can make a engine-out landing with your airplane or heli.

    In the flashlight world we've got as wide a range of options with our Li-Ion. Directdrive flashlight, and we can notice the drop in brightness. Maybe. Protected battery, and the batteries cutoff when empty. Intelligent/fancy flashlight and the light itself gives warning signals when battery starts approaching low.

    One thing though, outside of hobbyists, in the comercial space, there's always protection circuitry or battery management systems.

  5. #5

    Default Re: Lion vs LiPo? Which better, or are they just different?

    Is it true that a LiPo can discharge at 65C continuously, and 135C in bursts?
    While a Lion RCR chemistry 18650 2900 mAH can only discharge at 2C or 5.8 amps max???

  6. #6
    Flashaholic* Yoda4561's Avatar
    Join Date
    Jan 2007
    Florida, U.S.A.

    Default Re: Lion vs LiPo? Which better, or just different?

    If treated well lipos are more resistant to violent unexpected explosions, however they're soft and easily damaged in their natural form, and not very tolerant of poor charging habits. If you hold an RC Lipo pack in hand you'll notice it's rather soft and wouldn't be too hard to squish between your fingers, get too agressive with it and you'll get a vent with flame. Newer Lipos seem to be better about this, and cylindrical lithum cells are safer than they used to be as well.

  7. #7

    Default Re: Lion vs LiPo? Which better, or are they just different?

    LiPos come in all sorts of sizes, shapes, capacities, and power.

    LiPos made for cellphones usually have a max discharge rating in the range of 1C - 2C.

    LiPos made for RC typically range between 10C and 60C continuous rating.

    Li-Ions made for powertool manufacturers have much higher C rating than 2C.

    When in doubt check the specs and datasheet for the specific battery model.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts