Running out of batteries on a boat...

[Peter Ford]

Got a problem to solve with an upcoming shoot, where I might end up running out of batteries

I could do with some help:


i'll be shooting on a boat, and i'll be a 1 man crew, shooting for 5 days.

I will only have 1 8gig card, 1 16 gig card, and a sony ex hard drive available.

The original plan was to back up footage in the evenings to laptop and an external hd.

But i've now learnt the ships generator will only run during the day (when i'm filming)- so no power will be available in the night.

Which leaves me a bit of an issue - during the day, charger will be happily charing two batteries. Enough for my next day. However, my laptop doesn't have an express card port- i'll have to use USB through the camera- which means camera will have to be on and will use up the batteries which i will need for the next day. Sony's SxS card reader is no help - it needs external dc power

So, im very concerned im going to run out of batterys during this trip.


Only solutions I can see are:

1) My company buy or rent more SxS cards- so no need to transfer footage. (renting seems to be an issue- our regular rental place isn't very keen on hiring out their cards)

2) My company buy or rent more batteries for me to take out fully charged. (again, impossible to get rental)

3) Company or me invest in a laptop with an express card slot (not going to happen)

4) Find a way to power an SxS card reader from the laptop? - i know some portable HDs use two usb
ports, one for connection, one for power. Anyone powered a SxS card reader in this way?

5) Find somewhere to hire a Nextdodi type device- can these even be hired?


Any thoughts on this would be much appreciated!

[Jim Michael]

Have you thought of taking some sealed lead acid batteries and an inverter?

[Peter Ford]

Good idea, but getting to location with the extra gear wouldn't be that appealing. - im already going to be lugging quite a few bags of kit. Probably wouldnt be allowed in the hold of the plane either. (sorry, should have mentioned i've got to fly out there first)

Could be an option though if I could source one locally

[Alastair Traill]

Hi Peter,

Does the boat have a standby electrical system like a large 12 volt battery? If so you could consider an inverter to to produce 240 volts AC. These come in two types - pure sine wave and modified square wave, the latter are cheaper but some things will not run on them. I sometimes use a modified square wave inverter to charge my MacBook Pro but it only works if the computer's battery is down to about 60% charge.

Be aware of the capacity of the boat's battery and the amount of charge you are drawing from it. There are cut-outs available that would disconnect the inverter from the boat's battery when the voltage drops to a certain level. These save the battery from excessive discharge and hopefully leave enough charge to restart your motor when required.

Good luck

[Les Wilson]

The SWIT 8u62 batteries will run the Sony SxS reader using the same built-in connector that you use to power the EX when you use the to run the camera. They will also charge on your EX charger. Dolgin makes a battery adapter that will take your BP batteries and give you the same connector.

Another approach is to get a Hoodman Raw SDHC based SxS card and use the EX co copy your SxS cards in one slot to the Hoodman in another. THen use an SDHC card reader on your laptop to ingest the BPAV folder as usual with XDCAM Transfer or whatever.

Since you have the SOny hard disk, can't you copy the sxs cards to it in the same fashion and then import it to your computer from it's USB connector? I'm not that familiar with that device.

Lastly, I used an MxM SSD recorder but put a 320GB hard drive in it instead. I was then able to copy SxS to the MxM using the camera as described above. One problem is that it seems the EX only supports a maximum of 600 files and will report the MxM is full even tho there is available hard disk space. You can hook the MxM to your computer via USB or eSata.

[Peter Ford]

Thanks for the reply Les - all good options

My trouble is I cant afford to use any camera batteries in the footage capture process.

I can only charge two batteries a day- and those two will need to be used for filming the next day.

I really need to be able to capture just using the laptop and a bus powered reader - and after a lot of research, it turns out all usb express card readers wont work with SxS pro cards. Only device that does, is Sony's, which needs external power

Even the Sony hard drive unit i'll be taking takes a camera battery on board to run, even when hooking up to computer.


I think only answer is more batteries, and another charger, so while i'm filming I can leave 4 batteries charging on the boat.

I need to make it clear to the company i'm working with- it might cost a few hundred quid to get extra batterys and charger sorted out, but it'll be nothing compared to the reshoot cost if I run out of battery power!

[Bruce Rawlings]

You have answered your own question. It is not fair to have added pressures put on you when you have to come up with the goods. Simple - the job cannot be done without the additional batteries and perhaps another charger. This is part of the cost of the job, end of story. Even the cost of a Nexto is a cheap way out to have peace of mind within the budget of the whole project.. As you say reshoots would cost a lot more.

[Alister Chapman]

You can almost certainly hire extra SxS cards, batteries and chargers. Try Visual Impact or ProMotion.

[Dean Sensui]

You might want to consider using MxM's newest adapter and SanDisk's UHS-1 32-gig cards. Much cheaper than getting Sony's SxS cards, and each 32-gig SDHC UHS-1 card will get you 115 minutes of footage.

I might do the same thing you're doing on a fairly small boat. Not much room for anything except what's absolutely necessary.

[Peter Ford]

Thanks Alister - been trying all the hire companies today, but no-one will part with EX3 batteries.

I've tried visuals, promotion, alias, and procam. All say the same thing- the batteries only go out as part of a complete kit. The only hire out big boy batterys, V lock et al.

My company is just going to have to stump up for some extra batts and a charger.

What are peoples experiences of non-sony batteries? Is it a false economy, or do you get more bang for buck? I've had bad experiences in the past with non brand NPF style batteries

[Les Wilson]

I know what you mean about aftermarket batteries. In this case, Sony does not make a battery for the EX that also has a D-Tap. Other companies like SWIT and Switronics have stepped in and done so. The SWIT 8u62 is a proven product I can speak from experience about. There's also the Switronics 96 which is a different company, a bigger battery and lasts longer. You'll find a lot of folks here use them. Both have the tether to run the EX or SxS reader and a D-Tap.

[Peter Ford]

Les - thanks for that, top info, just what I was after. The swit looks good value for money, and especially useful that it has a d-tap. Found a place that sells Two large capacity swit's, complete with a charger- that should do perfectly

Thanks to everyone for all the suggestions, thoughts and info - you've all been a big help

[Les Wilson]

Oh. And one more thing. The location of the d-Tap is different on the different batteries. Some have it on the back and others on the bottom. It may matter to your rig in terms of the direction that the d-tap cable connector projects. I prefer the SWIT 8u62 design that projects the connector straight back. YMMV.

[Alister Chapman]

Swit 8u62 gets my vote as well. Very useful battery.

[Simon Wood]

You'll be filming on a boat.
You'll be filming during the day.
The generator is on during the day.

Can you just get a big extension cable and tether the camera to the power supply? How big is the boat?