Running a Laptop with 12 volt battery ?

iisollie

Would it be posible to power a laptop with a 12 v battery ?

ollie

longword

You can buy an inverter that'll turn 12V DC from a car battery into 220V AC that you can plug your laptop's PSU into. I'm sure the likes of Maplin and Peats have them. Probably around €60-€70 mark. It's not as efficient as trying to power the laptop directly from DC, but most laptops demand a higher voltage - often around the 16V mark. You might be better off looking for an extra laptop battery instead.

sirlinux

an inverter is the best way to go, plus you can plug more than one thing in, it also smooths out the power, a good one will even give you a decent sine wave. Running straight of a 12v would be difficult as when it's fully charged it's probably giving over 13 volts and heads down below eleven when it starts to run low.

BigEejit

Posted by longword
You can buy an inverter that'll turn 12V DC from a car battery into 220V AC that you can plug your laptop's PSU into. I'm sure the likes of Maplin and Peats have them. Probably around €60-€70 mark. It's not as efficient as trying to power the laptop directly from DC, but most laptops demand a higher voltage - often around the 16V mark. You might be better off looking for an extra laptop battery instead.

That is very power inefficient (DC converted to AC, which is converted back to DC), but if the laptop is to be used in a car and you want to use the power from the battery you can find a DC to AC with a cigarette lighter connector/attachment (I bought several of them off Maplin a few years ago for this exact purpose) ... but if you want to use your laptop for extended periods and are miles away from a power source or a car then get a DC to DC converter ... they can (usually) take a range of input voltages and a (few) specific voltage(s) ... all you have to do is get the correct DC/DC (matching input and output voltage and power requirements), the correct connector for the power inlet on your laptop and youre all set.... of course then you will have to lug a battery weighing a few stone around ....:D

longword

Originally posted by BigEejit
if you want to use your laptop for extended periods and are miles away from a power source or a car then get a DC to DC converter ...

Got a URL that'll sell me one of these beasties?

BigEejit

You will need to know the voltage needed for the laptop, and then try to figure out the power requirments (how many watts does it take maximum, power=voltage*current) and then go to maplin, farnell, radionics, any of the other component suppliers and buy one ...!

My dell latitude is 20 volts at 3.5a (sticker on the bottom of the laptop).. its been a long time since I did my power formulas but I reckon this is about 70 watts of a power supply

Just had a quick look, maplin has a 12VDC to 220VAC converter (160watts) for stg£39 (p/n VF69A), maplin dont seem to have DC/DC converters....Farnell have LOADS of them ... when looking at DC/DC's make sure the nominal input voltage is in the range 10-15VDC ... as was posted elsewhere the voltage of a standard car battery goes all over the place depending on its level of charge...

The last thing to check is the connector on the laptop, despite appearances, are usually not standard DC input jacks ... the pins in the middle are usually larger

iisollie

Folks,

Thanks for the info
I will check out both options

regards

Ollie

sceptre

I'm obviously the only one who thought this was a query about powering a laptop off a Duracell.:D (no, really, I did)

I suppose power wouldn't last long

Saruman

Is this a "Can i do it?" project or do you have some sinister plan to take over the world going on here?