How long approximately will a car battery run a laptop using a basic inverter for? Say a small-ish battery from my XR2?

Hi, I don't know the answer but it has always seemed rather wasteful using an inverter to provide 240v to power a transformer to take it back down to the laptop power of around 16v.
Ray

Typical laptop battery is 7ah. So 40ah car battery so 5 x the standard laptop run time. Maybe less with the invertor.

I would guess 6-9hrs depending what you are running on the laptop.

Tiz' a little wastful.

Try looking for Laptop in car chargers. they will have less wasted heat, be smaller more compact. They obviously wont allow you to power other 3-pin plug stuff though.

I used to use a 12v to 24v step-up inverter (bought from a truck-stop) and then a multi-voltage adapter that had various settings from 6v up to 19v, which worked a treat. Now I use a £3 inverter, bought from Asda, that plugs into the ciggy lighter, and that charges my phones and lappy. I've used the same cheap inverter to run the lappy off a car battery whilst using OBD software and it was still charging after 8hrs use!

My IBM thinkpad runs directly off the battery, try with nothing inbetween in the first instance.

Maplins have some car laptop chargers on offer at the moment - I've had one for ages and they work really well.

I run mine in the car using a dc/dc convertor from RS. Steps up from 12v to 19v (can't remember what's juice it rated at) and works a treat. Pretty much the same size as a standard laptop charger.

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Originally posted by whitestu
Maplins have some car laptop chargers on offer at the moment - I've had one for ages and they work really well.

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