Using Prius Batteries in an off grid

solar_dave
solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
in Off Grid Solar & Battery Systems #1
Seems to be quite a few of these available for sale, how would they play in an off grid RE system?
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
    Re: Using Prius Batteries in an off grid

    Technically the batteries themselves would be "ideal" but for two things: the Voltage and the price.
    They're 288 Volts I think; could be difficult to adapt to systems that generally run no more than 48 nominal.
    As for the price ... Gimme $30,000 and I'll let you know how it goes. :p
    Oh! You were just going to buy a battery pack? :p
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #3
    Re: Using Prius Batteries in an off grid

    I believe they use NiMH batteries and cycle them around 40-60% state of charge for long life.

    Battery bank:
    A sealed 38-module nickel metal hydride (NiMH) battery pack providing 273.6 volts, 6.5 A·h capacity and weighing 53.3 kg (118 lb)[55] is supplied by Japan's Panasonic EV Energy Co. They are normally charged to 40–60% of maximum capacity to prolong battery life as well as provide a reserve for regenerative braking. Each battery pack uses 10–15 kg (22–33 lb) of lanthanum. As each electric motor in Prius also contains 1 kg (2 lb) of neodymium, the car is described as "the biggest user of rare earths of any object in the world."[56]
    Lithium may not even make it into a Prius:
    Now we learn that the 2010 Prius was indeed supposed to have a new, more energy-dense lithium pack. But Toyota, by its own admission, chose the wrong lithium-ion chemistry for the cells, meaning they just couldn't be produced economically.
    ...
    That nickel-based chemistry turned out to have low materials costs but a much more complicated production process, making its overall cost high.

    As a result, Toyota concluded it had to switch its development efforts to a "tri-metal" electrode that combines cobalt, nickel, and manganese. That cell chemistry, Saga said, is less expensive to produce.
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #4
    Re: Using Prius Batteries in an off grid
    providing 273.6 volts, 6.5 A·h capacity
    That's 1,778.4 watts or at 48V only 37 amp hr. :(
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #5
    Re: Using Prius Batteries in an off grid
    mike90045 wrote: »
    That's 1,778.4 watts or at 48V only 37 amp hr. :(

    Isn't that per module? You could go through 1700 Watts pretty fast powering the car electrically.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #6
    Re: Using Prius Batteries in an off grid

    Probably somewhere around 200-400 Watt*Hours per mile:
    • 273.6 volts * 6.5 A·h 0.2 cycling range = 356 Watt*Hours usable
    Or around 1-2 miles of range... Googling around seems to state about 1 mile on flat ground for a 2010 Prius on battery only. Seems about right.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #7
    Re: Using Prius Batteries in an off grid

    The Pruis, by design, never gets below ~60% nor above 70% soc. This allows it to maimize battery life.

    Additionally, the battery is itself series of batteries that could b coupled and wired a number of different ways if one were to undertake the project.

    T
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  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    #8
    Re: Using Prius Batteries in an off grid

    They are all over eBay, just wondering if they could be cost effective, the number of charge cycles has to be pretty high. Shouldn't they be able to be wired to about any voltage. SOC on 60-70% range seems very conservative.
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  • TheBackRoads
    TheBackRoads Solar Expert Posts: 274 ✭✭
    #9
    Re: Using Prius Batteries in an off grid

    Cant remember where I read it, might have been Home Power.. anywho, there was an article of somebody buying a "used" battery pack for a Honda Civic Hybrid and taking each stick out and refreshing it. Saved a ton of money. Anyway, something to think about if you have the time or want a project..

    TBR
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #10
    Re: Using Prius Batteries in an off grid

    The 60-70% range IS conservative, by design to ensure battery longevity. A scan gauge installed in a number of Prius confirm this.

    Tony
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  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    #11
    Re: Using Prius Batteries in an off grid

    According to this guy the nominal voltage for the Prius battery is 220 volts. If you dig into his site he has lots of test data and describes how he bought a mid-range UPS which requires 220 volts nominal for home backup (leaving the Prius running to act as an inverter-genset). This is the site that convinced me to buy a similar UPS for my house but I ended up buying a dedicated lead-acid battery bank instead of using my wife's Prius.

    http://www.priups.com/tests/summary.htm
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
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  • sub3marathonman
    sub3marathonman Solar Expert Posts: 300 ✭✭✭
    #12
    Re: Using Prius Batteries in an off grid
    icarus wrote: »
    The Pruis, by design, never gets below ~60% nor above 70% soc. This allows it to maimize battery life.

    T

    That is not correct, and as a Prius owner I hopefully can add some information.

    For the state of charge, it varies between 40% and 80%, as can be seen at: http://www.eaa-phev.org/wiki/Image:Index.54.jpg and was developed by Wayne Brown, a person who has extensively studied the Prius.

    For the batteries, there is a real danger in recharging them. One lady in England burned her car up because of inadequate charging safeguards: http://priuschat.com/forums/gen-ii-prius-modifications/48653-plug-in-hybrid-electric-vehicle-mod-under-way-bristol-uk.html , you'll have to read the thread and it also shows some photos in there too.

    It is possible to rearrange the cells to go to 48V, but the main problem is each cell is only 6.5 Ah. Panasonic, the supplier for the Prius, used to make a spectacular large-format NiMH battery which was used in the Rav4EV, but the Cobasys/Chevron patent lawsuit put an end to them. (On a side note, I keep hoping to hear some news about these batteries again, since it is my understanding that this patent expired.)

    There has been speculation about using true EV batteries that have been depleted to about 80% of capacity for storage, but using that basis on the Prius battery, you'd only have 5.2 Ah of capacity per cell. So you'd be using more cells, and each cell would be more expensive on a per kwh cost.
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #13
    Re: Using Prius Batteries in an off grid

    Sub3,

    Not to disagree, but with a calibrated scan gauge, I have never seen the HV Prius battery drop much into the 40s nor rise appreeciably abov 60%. I super the difference is in how one is calculating SoC. We are however in basic agreement.

    T.
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