Lithium Ion Batteries

Discussion in 'Equipment' started by BlueSkyGuy, Nov 27, 2012.

  1. BlueSkyGuy

    BlueSkyGuy Been here awhile

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    It is time to replace my oem after 6 years and 55,000 miles the punch is getting weak. Thinking of upgrading to a Lithium Ion Battery (Ballistic) at about twice the price but one fifth the weight. Any feed back?
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  2. Morgan Steele

    Morgan Steele Been here awhile

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    If you're getting 6 years/55k miles on a battery, I wouldn't change what you're currently doing. In AZ, batteries fail much more quickly because of the heat. I switched to Li-ion to get some longevity.
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  3. _cy_

    _cy_ Long timer

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    have posted this several times, but here goes again:

    for most folks, my advice is go with AGM. unless weight is totally critical. AGM has one of the main advantages of LiFePO4 which is very low self discharge. unless one has a large parasitic current drain. trickle charger will not be needed for LiFePO4 or AGM over the winter.

    some bikes normally have a small self discharge. for those bikes a trickle charger will be needed regardless of what type battery is used. Your lead/acid battery charger may or may not properly charge LiFePO4 batteries.

    if you've got a modern adventure bike and decide that it's worth $$$ to save 10 lb or so over AGM or Gel. forget the marketing hype mfg use to calculate which battery to use.

    use actual amp hour rating less 25%. note this is for modern Adventure bikes, which has one of the highest battery demands of any bike. example, if factory ratings is 12 amp hour x .75 = 9 amp hour actual LiFePO4 amp hour rating.

    some bikes that only are used in fair weather can get by with much lower LiFePO4 amp hour ratings. one advantage of LiFePO4 batteries is ability to deliver larger amps for size, while maintaining a very flat discharge cycle.

    learning how to start your bike with LiFePO4 in cold weather is mandatory. yes procedures are different.

    take mfg amp hour ratings with a bucket of salt... use real amp hour ratings to size your LiFePO4 needs. LiFePO4 batteries when sized properly are robust, super lightweight batteries.

    visit LiFePO4 link in sig if you need details why ...
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  4. AKDuc

    AKDuc Alaska Born Ducatisti

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    I think you meant lithium iron instead of ion. Big difference.

    I'm kind of a weight fanatic and 10lbs is a lot to me so I went lithium iron a few years ago.

    I've had flawless performance with both Ballistic and Anti-Gravity batteries in a '00 Ducati 996 and a '07 KLR for a few years now. This includes sitting a few months during winter w/o any kind of charger on them. There was an inmate on here selling one one brand but I've forgotten which if you want to do a search.

    Good luck and have fun, Mark H.
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  5. Twilight Error

    Twilight Error Going nowhere slowly

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    I wouldn't bother.

    The 7lbs you'd save is, at best, 3% of the weight of the bike. You'll see a much better performance gain by putting yourself on a diet and regular attendance at a gym.
    The batteries are capable of an impressive pulse discharge, but in the real world, so are modern Lead Acid batteries. Your starter isn't going to draw the full discharge of either type.


    As far as Li-Ion vs. Li-Iron, they're the same. Li-Ion describes the movement of a lithium ion across a membrane during charge and discharge cycles. Li-Iron is just a variant of the chemistry, which includes Cobalt and Manganese Oxide based versions. LiFePO handles abuse better than LiNiCo, but isn't capable of the same high charge and discharge rates.

    I used to build these things for military aircraft, more satellites than I care to recall and even one submarine. I would not put one in my motorcycle. The charge control and balancing electronics, when present, aren't very robust or effective.
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  6. _cy_

    _cy_ Long timer

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    ah .. another battery guy flushed out :D

    the only constant in battery technology is change. how long since you were building batteries?

    odds are LOTS of advances in battery technologies. for instance due to inherent stability of Lithium iron phosphate. BMS or battery management system if used at all are minimal in design. individual cells have a small shunt that bleeds off excess current once a set volt is reached. this allows cells that have not reached full charge to continue to accept current.

    BMS large enough to handle the 200amp+ current draws needed would be larger than motorcycle size LiFePO4 battery. not even considering costs...

    to get up to speed on latest tech... follow link in sig
    #6
  7. Boatman

    Boatman Membership has it's privileges ;-)

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    Question for the masses regarding lithium iron batteries????


    I keep reading that they require special chargers, that's fine. But what happens when you put them in your bike that does not have this "special charging" capability? Does the vehicle charging system adapt to the charging needs of the lithium iron battery??
    #7
  8. C/W

    C/W Adventurer

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    Lithium *Iron* batteries have a max charge voltage of 14.4v which is higher (it better be!) than what your voltage regulator is going to provide. As long as your bikes charging system is in good working order things will be fine, although you'll probably never fully charge the battery. Given lithium batteries flat voltage curve under load you'll never notice in day to day usage.

    To fully charge & balance the battery you'll need a charger that can charge Lithium batteries. Most hobby stores (online & brick) carry Lithium (LiPO,LiFe,etc...) battery chargers that can be used. You just have to find the correct adapters for balancing & charging.

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  9. _cy_

    _cy_ Long timer

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    an excellent question... most bike charging system when working properly will put out 13.8-14.2v.

    a LiFePO4 battery is fully charged at 14.4v, but that number is deceptive. there's little effective power from 14.4v to 13.6v. most of power happens 13.6v to 12v in an extremely flat curve.

    [​IMG]

    [​IMG]

    a common question .... will a standard lead acid battery charger properly charge my LiFePO4 battery?

    answer is it depends on the charger. for not all lead acid battery chargers work the same. it's best to use a charger designed specifically to charge LiFePO4 batteries. But one can improvise and use a charger designed to charge lead acid by carefully monitoring charge. then remove when charge gets close to full. being careful not to exceed max voltage of 14.4v for LiFePO4 batteries.

    Cellpro Powerlab 8 is what I'm using. A favorite of the RC world. considered the most powerful/versatile of all hobby chargers with software to track charge cycle and generate graphs.

    here's my charge station with a full electronics lab
    [​IMG]
    #9
  10. C/W

    C/W Adventurer

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    This chart would be a good thing to print out and stick on the top of the battery. Providing it's accurate of course. :)
    #10
  11. _cy_

    _cy_ Long timer

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    yup it's accurate ... note LiFePO4 battery's narrow range, almost all available power falls within 13.6v-13v.

    a known to be accurate meter is required. one can successfully use cheapo Harbor Freight meter, if meter has been checked to be correct against a quality meter like Fluke 87V.

    if you don't have access to a Fluke meter. simply take a 3v lithium battery into a HVAC supply that sells Fluke 87V. then proceed to measure battery with both meters. Tell the salesman exactly what you are doing. they won't mind letting you check out new meter.

    [​IMG]
    #11
  12. Twilight Error

    Twilight Error Going nowhere slowly

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    Less than 5 years. I keep up on the tech through NASA Techbriefs, my IEEE membership and industry publications. The last batteries I built were for the X-37. They were power for the avionics and control surfaces during re-entry, it didn't burn up when it came home, so I must have done something right.

    My problem with the commercial LiIon batteries is cell matching. Every cell, no matter how consistent the manufacturing process, is a little different.
    A simple BMS system will shut off charging when the top cell reaches a full charge, leaving every other cell slightly lower, these systems are typically found in power tool batteries. This protects the battery against overcharge, and while LiFeX is more tolerant of overcharge than other variants, it still suffers an effect. Overcharging causes the Lithium to plate out on the anodes. The Li is then unavailable for movement across that membrane, and the capacity of that cell decreases. So the top cell loses capacity, but at the same time, the other cells are chronically undercharged.
    A battery that lacks a BMS system will let the cells overcharge, our motorcycles do not have any ability to shunt excess power to ground when the battery reaches full charge. A Lead acid battery, esp. the modern VRLA and AGM units, tolerate it just fine and don't appear to suffer much in the way of dendrites and other uglyness.

    If the battery starts with a set of tightly matched cells, it will delay the onset of the overcharge/undercharge cycle, but it won't prevent it. A good BMS system will use a DC-DC converter to regulate the voltage and current fed to the cells and a bleed resistor array to shunt power from the high cells while the low cells continue to charge. Charging will shut off when the low cell reaches full capacity. This is easy to do on a spacecraft designed to use a battery of this type, it is not so easy to retrofit a motorcycle with an 'always-on' charging system. Any BMS used with the charging system we've got on our bikes will need to shunt all excess power to heat, I don't see any of that in the current crop of LiIon batteries.
    And none of this addresses the thermal management issues of these batteries. Heat kills LiIon. Cold kills LiIon. We got around the heat problem by attaching the battery to an actively cooled heatsink. Cold was overcome by attaching heaters to the case. All the batteries I built used prismatic cells, which are far easier to manage from a thermal perspective than cylindricals, which are the cells used in every LiIon battery sold for motorcycles. I've seen active cooling systems for cylindricals, but the water jackets are heavy and require their own hardware. They do have a benefit in being able to maintain the battery at a stable temperature, but again, I don't see this feature on the offerings for our market.
    Some of The stuff I worked on 5 years ago still hasn't reached the civilian market, it may never get there.
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  13. _cy_

    _cy_ Long timer

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    ah... makes sense why you think all that... well dump all that out the window. Li-ion or lithium cobalt required an entirely different set of protections.

    li-ion is an inherently unstable chemistry in that it will accept a charge long as it's delivered, until thermal runaway occurs about 4.35v or so. so special protections had to be built in to prevent this from happening.

    main disadvantage of LiFePO4 is energy density is about 1/2 of Lithium cobalt. but so much more stable. most importantly 4x 3.0v-3.6v = 13v-13.6v falls within our motorcycle's 12v electrical system. vs lithium cobalt 3.7v-4.2v range doesn't match 12v systems without some type of voltage stepup or down.

    now days BMS can be a full blown protection circuit that can isolate entire load. or the most commonly used scheme is to use four individual boards that protects each cell individually. when that particular cell reaches full charge cutoff at say 3.65v. rest of cells that have not reached cutoff will continue to charge until cutoff is reached. that that point excess current is shunted off.

    note how each individual cell is protected by a independent BMS. picture shows a true 20 amp hour LiFePO4 battery. originally designed for electric scooters.

    please consider dropping in my LiFePO4 testing thread .. link in sig

    [​IMG]
    #13
  14. AKDuc

    AKDuc Alaska Born Ducatisti

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    Wow, interesting thread.

    Thank you guys for taking the time to share.

    Mark H.
    #14
  15. AdrianB1

    AdrianB1 Adventurer

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    Guys, please help a noob like me to understand: what kind of lead-acid batteries do you have on the bikes with the weigth around 10 lb? My Honda CBF 600 battery was ~ 5 lb and the Yamaha Fazer's is about the same, so why should I care about saving the weight of the breakfast?

    Also I am interested in the lifetime of the Li-Ion batteries: what I read about that suggests that the useful life is just 3-4 years at most (and just a couple of years top if used in cell phones), my lead-acid battery I changed on the CBF last spring was 8 years old, so what is the deal with Li-Ion?
    #15
  16. cyborg

    cyborg Potius Sero Quam Numquam

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    Not quite right, Shorai motorcycle batteries are flat-pack prismatic cells. No BMS, but wired for external smart charger.

    This is the cell pack inside a Shorai LFX18A1-BS12

    [​IMG]
    #16