Get a hybrid automotive grid charger/discharger and harness. You don't have to fuss with building your own and you have (I believe) a 3 year warranty. If you really feel like messing with building your own charger/discharger there are tutorials o believe to building your own. Do it wrong and you will cook your battery. It's also a lot more difficult building a harness for a HCH than an insight, before anyone says otherwise.
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