Welcome to our community

Be a part of something great, join today!

Log in
  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

External power for a MacBook Pro laptop?

OK, I know I'm going to get shot down in flames here for suggesting this, but what about this for a cheap solution...

A portable golf cart battery - £40

pga22-12side.jpg

http://bit.ly/GolfTrolleyBattery​

Battery Charger - £50


A Mac car charger - £23

RAP85CW_2.jpg

http://bit.ly/Appchar (And don't scoff at the 'Made in China' label - take a look at your current Apple charger and you'll see that's made in China too)​

So my thinking is you don't wait for your MBP's battery to run down (why shorten its life?) but leave this plugged in providing external power. If the golf cart battery runs down the MBP's internal battery kicks in. There are bigger models of cart battery to choose from, and you can have one on charge somewhere near mains power while you're using the other. the charger is a full 3 stage trickle charger (overnight), but there's a cheap portable 2 stage battery charger here - http://bit.ly/aEUBoR (works fine on my boat!)

As for the G-Tech external hard drives - they need a 12V power supply, so could have their own battery (one battery perhaps serving two drives) and would only need a simple voltage regulator.

Thoughts? I'm bound to have overlooked something... :undecided:
 
Ah! Just thought of something.

The MBP requires an external voltage of 14.5 to 16.5V (though I’ve read of different figures on the net, but let’s stick with that for what I’m saying now). Let’s say the golf battery and car adapter give an output of 15V. After some hours it starts running down, but is still above 14.5. Then you choose to transfer large amounts of data, the hard drive starts up and the MBP draws more current causing the voltage to drop below 14.5. This makes the MBP switch to internal power (would this cause a possible glitch and corrupt data?). But now, because the golf battery is not under load, its voltage goes back up to above 14.5 causing the MBP to switch back to that. Once under load again the voltage from the golf battery drops, and the MBP switches back to internal, and so the cycle goes on…

Or have I completely misunderstood this?

One cure would be some kind of power monitor you could keep an eye on and unplug the battery when the power begins dropping. Or maybe there’s a Mac app already available..?
 
I would just build a battery system from a RED Brick or any V-Mount using a spare Red Battery Plate a DC-DC converter and a custom made cable. That way you can power form batteries you already have.
 
Another one would be the one IDX is making (not out exactly). It would provide the power to the Mac Book Pro and regular video 4pin canon output, powered by regular IDX video bricks.
 
Hawk-Woods make a range of Broadcast/video camera battery plate adapters for macbook Pros including v-Lock, NP-F & BPU adapters which are all available for sale immediately. If you have some compatable batteries and a charger it would make sense.

I am in no way affiliated to them just saw them at a trade show a while back and they looked really handy.
 
Karel,

I like your thinking here and was heading in that line of thought for a DIT vehicle or cart but struggling with finding power consumption figures for working out the power consumption for a full Mac Pro tower, RED rocket and pair of external raid drives - which is the kit would want to get further down the line and be able to power for a full 16-18 hr day (plus have fully recharged by the next morning) .
 
I asked about this in the Apple forums, and someone's reply seemed to be that he was using something like this http://www.halfords.com/webapp/wcs/...&TB_C_TITLE=Halfords Power Pack 200&width=800 to run and recharge his Macbook via an inverter. :laugh: "300 watts of portable mains power for TVs, laptop computers etc. anywhere!"

I asked if he'd considered running the Mac using the car adapter I linked to above http://bit.ly/Appchar but he hasn't got back to me yet. I bet that way it'd be twice as efficient.

And I bet you could run the external drives off that. 12V - why not? And even pump up your car tires while you're at it!

It's worth remembering that the RED camera only exists because someone was prepared to think outside the box...
 
I've been mulling this over some, and I don't think I should take any chances with possible data glitches. Tempting as it may be to experiment. :emote_head_explode: But that doesn't mean those cheap portable auto-based backups should be dismissed. They're a very viable way of adding a bit of juice to an MBP's battery when things are a bit quiet, but you still can't get to mains power. But then, I've found that's rare. The only time I've ever been on a shoot where there hasn't been mains somewhere or a decent genny was out on a fishing boat. And I bet they had a 12V outlet somewhere. If the need ever arises I'll shell out for the expensive options mentioned earlier.

Was a time when asking production to hire a couple of extra camera batteries would be the solution...
 
You must log in or register to reply here.
Back
Top