12V -> 230V Inverters (running a lappy off 12V)

[NickK]

I'm looking at ways to run everything off 12V (ie looking at the powerstation thread). The fun is that the MacBook Pro uses 18V with a apple magnetic connector, so it's worth just running through the adaptor via 'mains'.

On battery the MBP will run for 4.5hrs (old '07 MBP) doing normal things but about 3.5-4 hours for harder use (ie fiddling with images etc). I could use a second battery but I was thinking of something like this:

Pure Sine Wave 150W DC 12V to AC 230V Power Invertor Free Delivery : InCar Power Invertors : Maplin

Anyone used one of these?

I'd be looking to run it off a large 100Ah Bosch S5 battery which will power the mount etc too.

[Macavity]

Hi Nick... For the moment, I'm just trying my (NC10) Netbook via a Maplins:

100W Laptop Car Adaptor with USB Charging Socket : InCar Power Adaptors : Maplin

Provisionally, it works well! Just jacks up the nominal battery 12V to 19V in this instance. FWIW, a wide selection voltages and "tips" (plugs) come with this device....

For what it's worth: I am about to try out one of Maplins NON-sinusoidal 240V / 300W invertors. About all I could afford! I'll let you know if it works?

Without much consideration of your own circumstances, just wondering if you NEED to go via 240V? Like you(?), I am quite keen to get my new observatory running on 12V - At least for now.

[NickK]

Without much consideration of your own circumstances, just wondering if you NEED to go via 240V? Like you(?), I am quite keen to get my new observatory running on 12V - At least for now.

The problem is that the MBP uses an Apple specific connector. The connection is flat and the pins are held against the latop power pads by magnets. If you pull the connector then the connector comes away as if you were pulling apart a magnet rather than ripping out the socket. The down side is that the connector isn't available normally as Apple patented it.

So running 110-230V would be fine. The only thing is non-sine wave can cause a problem with some transformers (the same reason you should not run an audio amp off a uninterruptable power supply).

The inverter would be off normally (ie lappy running off battery to ensure it keeps it in power saving mode) then when on reserve, switch on the inverter for the period to charge the laptop (and run it). Cycle and repeat as required..

The MBP's power adaptor is 86W, so 150W (300W peak) means the inverter isn't running at an inefficient maximum rate (they tend to have peak efficiency at a particular load). It also allows things to be plugged in if required in future..