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Hi I've got a higher end laptop where the need will be arising to charge it when on the move. For background info; the boat itself has a 12V, 176AH [upgrading to 264AH later] leisure battery bank charged off a 60-Amp alternator onto a generic 1000 Watt modified inverter [upgrading later to a Sterling Quasi 1800 Watt unit]. Though I could charge the laptop from the Inverter, feel it would be wasteful going from DC to AC, then back to DC. The laptop itself already comes with a 19V external power supply brick rated at 180 watts which I guess gives about 87%ish conversion efficiency. Despite it's max rating, using a watt meter has shown the laptop at it's absolute maximum stress only draws 145 watts from the wall. On lesser use with browsing & youtube it only draws about 45 watts when fully charged or double that when charging at the same time so shouldn't suck my batteries dry with the engine off. To avoid the unnecessary use of the Inverter, I've been looking into DC-DC regulators / converters and was after peoples experience with them. Initially I've only found one from Maplins which claims to be rated at 150Watts output [selector on 19V claims to deliver 8A] but I am sceptical as it only comes with a cigarette plug input which would most likely fry beyond 90 Watts and the body shows no signs of heat dissipation. Digging further, I came across this wide range input [9-19V] heatsinked version on eBay http://www.ebay.co.uk/itm/251375457679?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_3711wt_1162 and was wondering if this is a solution? Given it's claimed 90% efficiency, it shouldn't overload as the wattage should be a little less drawn in equivalent amps than the current laptop brick. The bare ended wires will also allow soldering on a barrel jack of my choice and it can be mounted next to the inverter taking it's power directly from the inverter input terminals. Would this source be a problem? My assumption was that taking the high amp draw from the thickest cables would minimise any voltage loss. I also noticed similar 12V wide-input regulators here http://www.ebay.co.uk/itm/DC-DC-Power-Converter-Wide-Range-Regulator-8V-40V-to-12V-6A-70W-/300950050478?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item46120556ae#ht_3221wt_1162 of a similar design. I figure I can just rewire the ends on to a standard cigarette socket & plug to act as a pass-through in the final stage of my 12V system. My reasoning is I can then run more voltage sensitive stuff like standard domestic TV's [with external 12V bricks, bypassing them entirely] directly off my 14V alternator. Are there many here who regulate their DC? On another note, I'm also looking at mounting a small victron 15A MPPT solar regulator next to the inverter and was wondering if I can attach the regulator output wires onto the inverter input terminals as well to allow charge flow down the thicker cabling direct to the batteries and avoid extra wiring.