I run a Magicshine MJ-872 headlight and MJ-818 taillight off of a single battery pack using the splitter/Y cable included with the 818 package. I'm working off-hour shifts more lately and using 2 commuters, and looking for an easier way to switch my lighting setup between bikes. I tried self-contained units but found the mounts cantankerous and the lumens inadequate. Is there perhaps an adequate battery pack with 2 input/output lines? Anyone with a similar, portable setup worth sharing?

Many thanks.