If what you are saying is you only have one cigarette lighter plug, and you already have something plugged into it, then yes... they make a plug that has two plugs. It turns your single outlet into two. Or, get yourself a Lithium-ion battery pack that has a 12 volt output.
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It has a cable that will fit the 436HP or SDS100, and has enough power to both run & charge the SDS100 at the same time. (The 436HP, as already noted, must be turned off in order to charge.)
It also has two additional USB ports for powering additional devices.