Jump to content

Alexa Mini - lowest battery voltage to run


Steve Conry
 Share

Recommended Posts

We've been shooting on our Mini for a bit now and have had the camera power down a couple times during operation. So far we haven't had any data loss but I have read about the potential to lose an entire card if the camera shuts down due to power loss.

 

I have been looking around but have yet to find the recommended voltage to pull batteries at. We are using Anton Bauer Dionic HC and 90's, as well as the Switronix Hypercore Slim (75wh).

 

Thanks for any insight!

Edited by Steve Conry
Link to comment
Share on other sites



I pull my batts between 14V- 13.5V.. under that they will go really fast.. you should only lose your last clip not the whole card.. unless you have one long take of course..

 

90 and 75 are fairly small capacity.. .. personally I,d get some bigger batteries .. even my 146 WH iDX duo,s are really small.. they are no longer "brick batteries"..

Link to comment
Share on other sites

Thanks for the reply Robin. I prefer to keep the camera as small and light as possible, so I'd like to stick with these batteries, even if it means I need more of them. They usually last about an hour or more. Im just not really sure what voltage the camera dies at specifically. Curious if anyone knows when that is so I can set my low battery voltage reminder a bit above there and avoid issues.

 

Thanks!

 

I pull my batts between 14V- 13.5V.. under that they will go really fast.. you should only lose your last clip not the whole card.. unless you have one long take of course..

 

90 and 75 are fairly small capacity.. .. personally I,d get some bigger batteries .. even my 146 WH iDX duo,s are really small.. they are no longer "brick batteries"..

Link to comment
Share on other sites

Like all Alexas, Alexa Minis are voltage regulated and can accept between 10.5 and 30V. See technical specs on the Arri website.

 

But the voltage cut-off point depends on the battery being used. You don't want to be draining a 24V battery down to 11V for example.

 

As a general rule of thumb, once a battery is down to about 10% below the nominal voltage, it's depleted and ready to be swapped out. Past that and the voltage will start to drop more quickly, depending on the cell condition and capacity, and the load being drawn.

 

So for 14.4V batteries for example, a safe low voltage warning setting would be around 13V. Some people set it as low as 12.5V, but a low capacity battery that's seen some use and is powering accessories as well as the camera might start to plummet around there.

  • Upvote 1
Link to comment
Share on other sites

Steve.. Im not in anyway connected to iDX.. but they have some new high capacity batts out now that are very small in size and weight and relatively cheap... worth checking them out if you are thinking of getting new ones.. my batts are 16V fully charged and on iDX advise, I don't use them lower than 13.5V..

Link to comment
Share on other sites

  • 3 years later...

There's a correct answer to how low you run your batteries down to, and it's based on what the cells in the battery pack are rated for.

14.4v "nominal" packs we use for camera is typically a 4s3p config...4 groups of cells in series, creating the 14.4 voltage, and then 2 or 3 cells in each group, creating the Ah or watt-hour capacity. (the P part of the 4s3p above)

Modern lithium cells are usually specced at a range of 4.2v at max charge, to a low of 3.12v or 3v when they are considered depleted. This is data off of spec sheets from the manufacturers like Sanyo and Panasonic.

That translates to a depleted pack voltage of 12.5 to 12v

You are good depleting to 12.5 for sure..my new Bebob batts are specced to 12v. The dual battery plate I got from them runs each pack down to 12.0 before switching.

You do no harm running down to 13 and swapping out of course...it gets you more cycles out of the battery pack. But cells made in the last few years will be good from 300+ cycles down to 3-3.12 volts.

If you're wondering how I know so much...I lost a lot of Anton Bauer packs on rentals and I thought it was because people were running them down too much. There was another problem. But I learned a lot along the way.

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

Forum Sponsors

Film Gears

Serious Gear

Metropolis Post

Abel Cine

Tai Audio

New Pro Video - New and Used Equipment

VidGear.com - Broadcast Video Warehouse

Visual Products

Gamma Ray Digital Inc

Broadcast Solutions Inc

FJS International

CineLab

Wooden Camera

Cinematography Books and Gear

TripdsVideo CamerasLightingVideo Camera LensesMonitors

ADVERTISING INFO


×
×
  • Create New...