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Anton/Bauer battery LCD showing single bar across middle of screen


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#1 pauldudeck

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Posted 23 June 2009 - 01:54 PM

Guys,

After speaking with a number of you during CineGear Expo, the most common issue that I heard was "my battery shows a single bar on the LCD".

After double-checking here, I confirmed what I thought was happening; when putting 2 or 3 batteries onto a sled, you need to be sure that all batteries are isolated from each other. Otherwise, one battery can backfeed (or essentially try to charge) another battery. You can do this by simply adding a diode in series with the battery. This is not good for the batteries, as the weaker of the batteries is the one that will try and take a charge from the other and this will shorten the life span of it.

The single bar on the LCD is stopping the battery from communicating with a false charger, as a preventive measure. So, the battery will still work and the LCD will return to normal once it is returned to the charger....

Paul
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#2 Sydney Seeber

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Posted 23 June 2009 - 03:24 PM

So I wasn't the only one, huh?

Thanks man
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#3 Andrew Stone

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Posted 23 June 2009 - 05:14 PM

Which stabilizers appeared to have this problem?
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#4 Jerry Franck

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Posted 23 June 2009 - 07:48 PM

Guys,

After speaking with a number of you during CineGear Expo, the most common issue that I heard was "my battery shows a single bar on the LCD".

After double-checking here, I confirmed what I thought was happening; when putting 2 or 3 batteries onto a sled, you need to be sure that all batteries are isolated from each other. Otherwise, one battery can backfeed (or essentially try to charge) another battery. You can do this by simply adding a diode in series with the battery. This is not good for the batteries, as the weaker of the batteries is the one that will try and take a charge from the other and this will shorten the life span of it.

The single bar on the LCD is stopping the battery from communicating with a false charger, as a preventive measure. So, the battery will still work and the LCD will return to normal once it is returned to the charger....

Paul



Hi Paul,

I have a PRO2 sled and I noticed recently that it did the issue that you've just addressed.

here's a picture: http://img14.imagesh...4/pict0089x.jpg

that is what we're talking about right?

So, can you explain again, how we can solve this problem? I didn't quite understand the diode thing...?

Thank you,

Jerry.
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#5 Kelsey W. Smith

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Posted 23 June 2009 - 07:55 PM

EXCELLENT, thanks for the info Paul! It's been driving me crazy for a long time now and I had no idea what was happening with my batts. I even went as far as taking my sled into a tech to have it checked out, but he said he counldn't find anything <_< .

So the answer is to just add a diode, too cool!

Cheers,
Kelsey W.
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#6 RonBaldwin

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Posted 23 June 2009 - 08:18 PM

sombody do a fix and take pictures of the wiring. Will fit in the ab plate or does it have to go in the lower jbox?

rb
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#7 Sydney Seeber

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Posted 23 June 2009 - 09:17 PM

I'm wondering could the problem be caused by attaching different chemistry batteries to a sled, in my case, a Hytron 140 and Dionic 90? I ask, because I never had the problem before I started doing that... Is it possible the Hytron 140 has enough oomph, if you will, to overpower the original diode? This may be a sled manufacturer question, but it doesn't hurt to ask.
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#8 Sydney Seeber

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Posted 23 June 2009 - 09:21 PM

Will fit in the ab plate or does it have to go in the lower jbox?

rb

I took mine apart, (jbox) and there isn't much in there, but there is one diode matching the description already in there... That's why I'm wondering if the battery chemistry is overpowering it somehow...
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#9 Jerry Franck

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Posted 23 June 2009 - 09:24 PM

I'm wondering could the problem be caused by attaching different chemistry batteries to a sled, in my case, a Hytron 140 and Dionic 90? I ask, because I never had the problem before I started doing that... Is it possible the Hytron 140 has enough oomph, if you will, to overpower the original diode? This may be a sled manufacturer question, but it doesn't hurt to ask.



I don't think it's a mixture of different type of batts.
I only use dionic 90's and I have the problem too.

Did someone ask Jack at GPI about this yet?

And yes, if someone has fixed it already, can we see some pictures?

thanks,
Jerry
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#10 pauldudeck

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Posted 24 June 2009 - 10:57 AM

Guys,

I will see if I can have one of the technicians in back put a diode in a gold mount and show you what to do. It is very simple and only requires a little soldering.

As for mixing chemistries, yes, this could be a reason why you may see if more often now. Let me explain; when a NiCad or NiMH battery discharges, it does so that if you graph it, it looks like your leg/knee when you are sitting down. There is some slight "skin voltage", around 16.9/17v, but once a load is applied, that voltage drops until it reaches a nominal voltage of around 14.4v, where it will spend about 80% of its time at discharge. Hence, a 14.4v battery. A li ion is different, and will discharge more linearly than a NiCd or NiMH.

So, if you are using two of the same chemistry, and close to in age, batteries, you may not see this issue. However it will still occur at some point. If you mix li ion with NiCad or NiMH, you may see it more because your piece of equipment will automatically be powered by the battery with the higher voltage. Once it reaches the same voltage of the other battery, then they will draw simultaneously. If one battery is a lot older than the other, then the discharge may go back and forth between batteries more often than you realize, because the cell impendance of the older battery is much higher and the voltage will drop quicker.

In any scenario, a diode will protect the battery from backfeeding, so I highly suggest that they are installed in your rig. Or, some type of protection against backfeeding. We typically use a 7amp / 20v diode. However, if you plan on powering a RED camera, you will need a higher current diode, like a 10amp, which would be a lot larger.....

I hope this helps...

Paul
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#11 Lawrence Karman

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Posted 24 June 2009 - 11:05 AM

I'm wondering could the problem be caused by attaching different chemistry batteries to a sled, in my case, a Hytron 140 and Dionic 90? I ask, because I never had the problem before I started doing that... Is it possible the Hytron 140 has enough oomph, if you will, to overpower the original diode? This may be a sled manufacturer question, but it doesn't hurt to ask.



I don't think it's a mixture of different type of batts.
I only use dionic 90's and I have the problem too.

Did someone ask Jack at GPI about this yet?

And yes, if someone has fixed it already, can we see some pictures?

thanks,
Jerry


This single bar has happened to my Dionic 90's once in a while. Usually when the camera is cold. Happened first day of this show and not since. Strange. Think this only happens when the batteries sit around unused and not freshly charged for a couple of days. I asked George at GPI maybe a year ago about putting a diode in and he said it was not necessary. The way the sled was wired it was not possible for one battery to back-charge the other. Using only 2 batteries in 24v mode, BTW.
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#12 pauldudeck

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Posted 24 June 2009 - 01:19 PM

This would only happen if you put the batteries in parallel for 14.4v, not for putting them in series for 24/28v.

Paul
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#13 Jerry Franck

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Posted 24 June 2009 - 02:19 PM

This would only happen if you put the batteries in parallel for 14.4v, not for putting them in series for 24/28v.

Paul



Lawrence, even in 12v mode, there's no problem, according to George?

btw, all my batts are brand new, about two old and they have this issue. But I noticed only the one on the AUX ports on the pro sled.

Yes, I would like to see some pictures from your techs, Paul.
I'm interested in the 10amp one because I fly the RED on occasions...

thanks,
Jerry
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#14 Alec Jarnagin SOC

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Posted 24 June 2009 - 03:55 PM

Out of the box, the PRO 2 base will never put your batteries in parallel. In 24 volt mode, the AUX and camera batteries are in series and in 12 Volt mode, the AUX battery and camera battery are each providing isolated 12 volts to their respective ports. Now, if you purchase the optional "12 volt only" block, then the back two batteries are in parallel. Also, if you use a "Y" power cable for the RED or Genesis that plugs into the AUX port and camera power port, then these two batteries will be in parallel. I just finished a RED feature using a "Y" cable and we occasionally had this problem with the batteries (had never seen it until then). Come to think of it, I was using the standard 12/24V block because you are putting the batteries in parallel through the cable (and if you flip the sled to 24 volts, it doesn't matter because the pins are not active on the cable). If you used the 12 volt only block with the "Y" cable is that somehow guarded against the feedback? (I don't think it would, but maybe I'm missing something).

Would installing this diode ever cause a problem?

Thanks.
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#15 Iain Baird

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Posted 24 June 2009 - 04:23 PM

When a PRO II rig is in 24v mode the two batteries are in series and can not cross charge each other as the (+)positive of battery #1 is connected to the (-)negative of battery #2 and together they make the 24v (closer to 32v actually and 28v under load).

In 12v mode it is another story though, there is nothing in the PRO II rig to prevent cross charging. One of the great things about the Pro is that there is no circuitry involved, it makes for a very rugged and easily field serviceable rig. That being said it is also very easy to add diodes to the PRO rig by placing them in the power jumpers. I have a few jumpers with different diode combinations to prevent cross charging.

In order to use a 'Y' power cable for the Genesis and other power hungry cameras each of the two batteries needs to be independently protected so two diodes are required, one on each battery. The diodes I use actually have two inputs and one output so they can protect one or two batteries at once as long as only one output is required. Another one of my jumpers is wired for paralleling two batteries to power the monitor if I'm in two piece mode using a Genesis and the camera is being powered by another source. I get extra long run times on the monitor this way and I need the weight anyways so might as well have the battery powering something!

Heres the diode I use, it's very low loss and just small enough to fit two inside the PRO power jumpers.

Attached File  diode.pdf   36.6KB   149 downloads

I used to get the single bar all the time until I installed these, I never saw it again. Panavision Toronto built a great battery belt for the Genesis that can parallel 3 AB 140's using the same diodes, it works like a charm.

The one diode already in the PRO II base is a voltage regulator hooked up the the recorder power output. I think it is a 9v regulator, I can't remember exactly as I've long since changed mine out for a variable voltage regulator.
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