I just installed the Journey kit on my bike and although the speed is adequate I know 48 volts will definitely give me what I'm looking for. I just took apart the Crystalyte pack and there are no markings on the D cells. My idea is to add another 10 cell pack in series and charge that pack separately. The controller is rated for 48 volts, so I should be OK with the higher voltage. The specs on the pack describe it as a 36v 8aH pack. I would like to get the same exact cells to keep everything in balance. Any ideas?