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Continuous Discharge Current Rating - Gen1 & 2 Battery Modules ?

Discussion in 'Generation 1 Prius Discussion' started by TexomaEV, May 10, 2013.

  1. TexomaEV

    TexomaEV Member

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    Is there any information posted about the Gen1 & Gen2 prius battery modules? I'm most interested in the Continuous Discharge Current rating of a single module.

    Wanting to make up some small battery packs, IE: 48volt for my Electric Riding Mower, but need to make up a pack with enough modules in parallel & series to get at least 50amp discharge capability. Thanks in advance!
     
    #1 TexomaEV, May 10, 2013
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  2. bwilson4web

    bwilson4web BMW i3 and Model 3

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    New, 6.5 Ahr. But you are looking at:
    • 50*48 = 2.4 kW
    Perhaps you might consider something like not a 'rider' but perhaps a 'walk along', self-powered? It will consume considerably less . . . do you have a big dog?

    Bob Wilson
     
    #2 bwilson4web, May 11, 2013
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  3. NortTexSalv04Prius

    NortTexSalv04Prius Active Member

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    So is the following correct 28 modules at 7.2vdc 6.5ah......201 vdc .
    for gen 2
    what about the following concerns/issues
    over charge voltage
    over discharge
    cycle age.
    be address.
     
    #3 NortTexSalv04Prius, May 11, 2013
  4. TexomaEV

    TexomaEV Member

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    I'm looking for how much current can one pull from them safely without damage. Some call that rating 1C, 2C, 3C., etc.

    1C = 6.5 amp continuous discharge
    2C = 13 amp continuous discharge
    3C = 19.5 amp continuous discharge
    and so on,
    10C = 65 amp continuous discharge

    Therefore most batteries have a maximum charge rating, and a discharge rating. Once these parameters are known along with the given Ah capacity we already know, one can easily build a battery pack to match required charge/discharge/ah/voltage needs for any EV project. Put modules in parallel to increase Ah capacity/Charge & Discharge capacity, and then those groups in series to increase the voltage to match the EV project's need. Once the pack is built, there are lots of inexpensive (scooter) chargers on the market from 12 to 6o volts DC, to charge the pack with. I do all this currently (pun intended) with Pb/acid batteries, but now that the Prius packs are readily available in salvage yards, I want to upgrade my existing projects to NiMh chemistry.

    Riding Mower: www.flickr.com/photos/mbarkley/sets/72157616705485636/
    Push Mower: www.flickr.com/photos/mbarkley/sets/72157606565232358/
    RotoTiller: www.flickr.com/photos/mbarkley/sets/72157618463643481/
    and so on....... :)
     
    #4 TexomaEV, May 11, 2013
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  5. Russell Walker

    Russell Walker Junior Member

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    They charge and discharge at 30 to 50 Amps in the car but not for long they are arranged with a variable cooling fan that should keep them at a reasonable temperature. 6.5Ah at 20A doesn't give you much time to mow the acre. Better getting a small heard of sheep. I could arrange a small family of kangaroos to keep the grass down.
     
    #5 Russell Walker, May 11, 2013
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  6. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Each module has six, NiMH cells, and as a general rule:
    • 8V is close to upper limit - no appreciable energy above 8V
    • 6V is the lower limit - no appreciable energy below 6V
    • cycle age - not well defined, appears to be a non-linear function of charge/discharge history
    Bob Wilson
     
    #6 bwilson4web, May 11, 2013
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  7. TexomaEV

    TexomaEV Member

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    ROTFLOL, I'll keep the sheep option on the table, but for now I will build up a pack with 4ea modules in parallel (26Ah) x 8 in series to make up a 48 volt battery for the riding mower. It's current pack is only around 15Ah, and gave me plenty of run time for my small lawn for close to 5 years now but the pb/acid has grown tired & weak.. I will have to charge the Pb/acid pack with it's 48volt charger and see what voltage it shuts off at, and make sure it's shutoff knee is within specs of the HIGH charge knee of the NiMh modules I'll have series into a pack. Seems like NiMh cells like to charge to 1.45vdc per cell (going by the "AA, AAA, C, D" cells charged in my microprocessor controlled charger), so a module's max charge voltage would be something like 8.7 vdc which is close to what Bob mentioned earlier.

    4 modules in parallel - 7.2 vdc nominal/26Ah/80amp discharge continuous (if 20amp per module seems reasonable)
    3 modules in parallel - 7.2 vdc nominal/19.5Ah/60amp discharge continuous (if 20amp per module seems reasonable)
    2 modules in parallel - 7.2 vdc nominal/13Ah/40amp discharge continuous (if 20amp per module seems reasonable)

    I believe the above will be my only options, dependent upon how much room I have under the hood of the riding mower to work with. Ideally the 4 modules x 8 in series would be best, but might be to large physically. Fun times ahead.......

    SORRY for the Off Topic Thread - There's not an area for (Odd Ball Uses for Prius Batteries) :)
     
    #7 TexomaEV, May 11, 2013
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