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Alexa Mini - lowest battery voltage to run


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#1 Steve Conry

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Posted 24 August 2016 - 12:06 AM

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, 24 August 2016 - 12:07 AM.

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#2 Robin R Probyn

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Posted 24 August 2016 - 07:14 AM

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"..


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#3 Steve Conry

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Posted 24 August 2016 - 11:44 AM

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"..


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#4 Dom Jaeger

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Posted 24 August 2016 - 07:38 PM

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.


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#5 Steve Conry

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Posted 24 August 2016 - 08:04 PM

Thank you very much Dom! Exactly what I was looking for!
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#6 Robin R Probyn

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Posted 25 August 2016 - 06:56 AM

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.. 


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