This is a good one for me as I have been in Automotive, Marine and
Industrial repair for 45 years.
Battery voltage on an 12 volt battery varies anywhere from up to 14.0V down
to nothing. Also connecting anything to DC current incorrectly could be a
disaster.
If I were you, use an inverter connected to the battery and simply plug
your laptop power plug into that. Electric motors that run at high or too low
voltages will not survive. plugged into an inverter they will be protected.
DC to AC inverters can be purchased for around $25.00 that will handle any
laptop.
Hope this helps,
Bud Jarman
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