I took my jury-rigged 48V pack and put it on my Tidalforce today for the ride in. The pack consists of the ebikekit.com 36 volt 12AH sealed lead-acid battery pack with an additional 12V 18AH SLA battery in series with it for a total of 48V. It was an exhilerating ride and a blast to be able to easily keep up with rush hour traffic. I also felt safer because I could pass parked cars at regular traffic speeds instead of slowing down to wait for an opening in traffic.
All-in-all, a very satisfying experience. I like 48 volts on my ebike. All I need now is to reduce the weight by swapping out the SLAs for lithium.