Video Assist 7" 12G rapid battery charge depletion

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97xvideo

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Video Assist 7" 12G rapid battery charge depletion

PostFri Jul 30, 2021 8:00 pm

Hello,
I have a new Video Assist 7" 12G that I am using with a new pair of 3rd party NP-F970 batteries. I am experiencing two issues:
1. The batteries discharge very rapidly with the video assist turned on and no recording in progress, and it can take less than 4 minutes for a fully charged battery to go from a video assist reading of 95% down to 65%. Placing that same battery back into a Dolgin charger shows that the battery is actually 80% charged.
2. Prior to updating to the latest firmware (3.4.3), when two batteries had been installed, the video assist's battery indicator would show the charge level for both. But now, the number two battery is grayed out, while t he number 1 battery shows the rapid depletion of charge.

Anyone else noticing issues with the Video Assist 7" 12G's power consumption and charge readings?
Thank you in advance,
Ron
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carlomacchiavello

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Re: Video Assist 7" 12G rapid battery charge depletion

PostMon Aug 02, 2021 7:46 am

Try to downgrade it. Remove newer software from computer, install older and connect videoassist, if it is a problem of firmware it solve the problem.


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97xvideo

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Re: Video Assist 7" 12G rapid battery charge depletion

PostMon Aug 02, 2021 4:06 pm

Hello, and thank you for the suggestion ... I may give it a try.
That said, I now suspect that there may be a battery related issue, as I've noticed that while the charger (a Dolgin) reports that the battery is fully charted, the Video Assist does not agree, and reports it to be less than 90%. So, before downgrading the firmware, I am awaiting the arrival of a new battery pair to see if they will solve the problem.
Thanks again.
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OlliVan

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Re: Video Assist 7" 12G rapid battery charge depletion

PostMon Aug 02, 2021 8:00 pm

The issue #1 happens to me too and I have just assumed it's very power hungry and I have understood others complain the same. It seems the battery draw slightly if you use a LUT.

I have also noticed that my charger thinks the batteries are more full than the VA shows. I have thought maybe it has something to do with the fact that the batteries are burning hot after a long shoot. Although I have never heard of such a behavior.

At first I Used NP-F550 batteries but changed to NP-F970 batteries. That makes the device too heavy to be mounted on a side or almost anywhere but on a desk. So I eventually bought a D-TAP cable and IMO that works decently fine, it still draws a lot of power but at least I can mount a large V-mount battery on a more convenient location on my rig.

#2: I'm on v 3.4.2 and I see the status of both batteries. Looks like it's better that I don't install the update.
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97xvideo

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Re: Video Assist 7" 12G rapid battery charge depletion

PostTue Aug 03, 2021 3:34 pm

Hello, and thank you for your reply.

It is nice to know that I am not alone with the battery/power observation. It may mean that my battery exchange arrangement will turn out to have been moot. And I agree that the NP-F 970 batteries are bulky and heavy, but I have continued to use them for want of a better solution. That said, I would be interested to hear about your D-Tap setup—from where obtained—and how you have mounted—where—the battery.
Regards,
Ron
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alexdolgin

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Re: Video Assist 7" 12G rapid battery charge depletion

PostTue Aug 03, 2021 4:05 pm

Hello, just wanted to share some thoughts regarding the Li-Ion cells, and charge level measuring. While there is a definite correlation between the battery voltage and the state of charge, it is hard to know exactly where the battery is at any given time. A fully charged DV battery is about 8.4V, discharged about 6V. But the discharge curve is not the same between different brands/models. And, most importantly if the load draws more current, the voltage sags. A higher capacity Sony 970 battery would have a lesser sag as it can deliver more power than a smaller one. All this makes displaying the percentage of charge prone to underestimation/overestimation by the simple built-in algorithms in the equipment.
The higher-end cameras talk to their own OEM batteries (Sony Cam - Sony battery) using their digital communication via their proprietary protocols. This results in much more predictable readings.
Hope this helps
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97xvideo

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Re: Video Assist 7" 12G rapid battery charge depletion

PostTue Aug 03, 2021 9:33 pm

Hello Alexdolgin,
I am using a brand new Dolgin turbo, dual charger for the NP-F970 batteries. What I've gleaned from your helpful explanation, is that the issue with charge determination is related to the accuracy of the algorithm used by the powered device for said calculation? If that is the case, am I to assume that when the Dolgin charger reports that the battery is "ready," that it is fully charged? As in, 100% charged?

I have yet to measure the voltage of a fully charged NP-F970, or a battery that is said to be "ready," but perhaps I should do so, as I have performed that test with other batteries, such as those that I have charged with a Dolgin Dual, turbo charger for the Panasonic BLJ-31 batteries that do not always read as 100% charged when inserted into, for example, a Panasonic S1r or S1h.
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alexdolgin

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Re: Video Assist 7" 12G rapid battery charge depletion

PostWed Aug 04, 2021 1:17 am

97xvideo, charging on the charger is much more deterministic and precise. Voltage measurements are not used to terminate the charge when fully charged. Our chargers terminate charge at about 97%-98% as the Li-Ion batteries service life is greatly improved this way.
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97xvideo

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Re: Video Assist 7" 12G rapid battery charge depletion

PostWed Aug 04, 2021 4:50 pm

Hi Alexdolgin,

Thank you for the explanation, it is very helpful.
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97xvideo

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Re: Video Assist 7" 12G rapid battery charge depletion

PostWed Aug 04, 2021 9:19 pm

Since the update to the latest firmware, I have noticed an element of strange behavior for the Video Assist 7". When I install a pair of fully charged batteries, the video assist's battery indicator will occasionally choose to begin using battery #2 as opposed to the battery in the #1 position. If I then switch battery positions the Video Assist will then begin using battery #1. Has anyone else experienced this strange behavior? There is nothing in the manual that explains this, and I haven't found anything on the Internet either.
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97xvideo

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Re: Video Assist 7" 12G rapid battery charge depletion

PostSat Aug 07, 2021 5:41 pm

This is a followup to my last post in re the Video Assist firmware, as well as batteries.

1. Following a conversation with Black Magic support, I tried to roll back the Firmware to version 3.4.2 by downloading that version from the BM website. However, despite the fact that it was labeled as 3.4.2 it was installed on the Video Assist as 3.4.1? I reinstalled 3.4.3.
2. I'd received a pair of brand new Sony NP-F970 batteries yesterday, popped them into the Dolgin turbo charger and found, that when the charger said 'READY' the batteries had only reached a charge of 85% as per the Video Assist. Put them back into the charger that later reported that they were 'READY' and the Video assist reported that they were now only 90% charged. I have a pair of brand new Wasabi NP-F960 batteries and placed them into the very same Dolgin charger, and when the charger reported that they were 'READY' I loaded them into the VA which promptly reported that they were 100% charged.

The moral of the story, at least IMO, is that at 6.8 times the price of the Wasabi, the Sony is not a good purchase ... so much for OEM superiority.

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