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    The care and feeding of a123-based packs...

    Before choosing a charge method, I want as many opinions as possible, so I emailed John Reid from BattleBots fame, who has a page with A123 info: (http://www.terrorhurtz.com/a123/). Conversation copied with permission: --- I'm looking at building a charger for a 10s4p A123 pack, to replace...
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    The care and feeding of a123-based packs...

    Thanks for the explanation Gary! That really helps. I see now, there are three basic ways to charge with balancing: -charge entire pack in (mostly) CC mode, cut off cells at threshold by dissipating current as heat, as described above -charge each cell individually with CC/CV chargers...
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    The care and feeding of a123-based packs...

    Some RCers already use CC/CV supplies to charge their A123s, and there's even a YouTube video showing how it's done with a Mastech 5020E supply. I think there's an issue with your overvoltage-threshold-in-series idea. I'll assume that a CC/CV charge is being used, with voltage set to...
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    The care and feeding of a123-based packs...

    lawsonuw, you want to check out Jeff's "BMS package for A123 cells" thread here: http://endless-sphere.com/forums/viewtopic.php?t=2387 It features an improved version of the MetricMind BMS schematic, with SMT components sized just right for the A123 cells. IF someone combines this with Bob's...
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    LiFePO4 Battery Showdown!

    Where are you sending the cells for spot-welding?
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    Custom A123 pack charging options.

    Doctorbass, This is an issue I've been looking into for the last month as well: do I use a big honkin' power supply or a multiple independent power supplies? I'm leaning toward going with a Mastech HY5020E 50V 20A supply, because there is so much info out there on using it as a CC/CV charger...
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    BMS package for A123 cells

    Below is a copy, with permission, of questions asked to Jeff via PM. He is busy, but is working on an amazing A123-powered EV Attack, with details at http://www.attackforums.com/showthread.php?t=2419 [First Email]--------------------------------------------------------- Hi Jeff, I had a few...
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    Custom A123 pack charging options.

    Can you give a part number and vendor for the extra-wide heatshrink? I've been looking for it, and have only come across some expensive stuff at buyheatshrink.com, 5". And I'd love to see your LVC implementation when it's done...
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    LiFePO4 Battery Showdown!

    Magudaman, There was an August thread on rcgroups where I guy cycled an A123 cell over 1000 times, then intentionally went over-voltage with each charge: http://www.rcgroups.com/forums/showthread.php?t=732148 Here's the summary text, copied from the first post in the thread: " A couple of...
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    LiFePO4 Battery Showdown!

    This link was posted to the evtech list yesterday, and it's definitely worth checking out. http://zeva.com.au/tech/LiFePO4.php It's a comparison of different LiFePO4 cells from Valence, Huanyu, PHET, and A123, in both discharge and charge. The author also posted a schematic and software (!)...
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    BMS package for A123 cells

    Cool! I've been looking at designing something just like this, to get away from having to use 10 cells with the DeWalt charger, with slow charging, on a 10s4p pack. This is a great first building block in the construction of larger automotive packs. A few questions: 1) It looks like you've...
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    A123 Charging and Pack Construction Questions

    Thanks for the info. Do you have any pictures of your pack? I'm having trouble visualizing it.
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    A123 Charging and Pack Construction Questions

    Hi all, First off, props to magudaman for pointing me to this forum at the Silicon Valley EV Rally last August. There’s a ton of great info here. I’m building a gyro-balanced scooter (aka custom Segway) powered by A123 M1 cells taken from Dewalt 36v packs...
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