Trouble shooting AB batteries powering 435

[Yuk Hoy Cheong]

Warmest regards one and all,

 

I hope some one can help me trouble shoot. I have a three batteries system for my set up. I went with Anton Bauer and own 2 units Hytron 140's, 2 units Dionic 90's and 3 units Trimpacs for my initial start, hoping that they will help me power up 435 film cameras.

 

I did a day's work successfully a month ago with no problems at all powering a 435 ES film camera running @ 25fps only.

 

Yesterday, my problems started. We were running the 435 ES @ 50fps. I had the combination set up - Hytron 140 for Accessories / Trimpac and Dionic 90 providing 30V to power the 435. Did about three takes of approx. 25 secs each and the camera stops showing LOW BATT. After changing the Trimpac, again we could do another three takes or so. I have tried the combination of 2 Dionic 90's to power the 435 but that failed. I had to revert back to having a crew to tag along behind me with the Rental house's 30V battery. Very embarrassing. Not a good sight.

 

Does anyone experienced anything like this? Hope you guys could share your thoughts or a light on this.

 

Cheers

cheong

[Mike McGowan SOC]

I don't know the trimpacks or the dionic 90's but I know the Hytron 50's.

 

For about a year, they should power the 435 at high speed with no problem (at least that's my experience). Once they get much over a year old (with normal use) you will have trouble with super high frame rates (120+ fps).

 

Your solution options are these:

 

Get new Hytron 50's.

or

Use one of your Hytron 140's for your camera power.

or

Use a camera house 30v battery (like you are already doing).

or

You could try starting the camera in 24fps and then fliping the switch to 50 (or whatever frame rate you want to shoot) once the camera is up to speed. If I understand correctly, your having trouble starting the camera at high speed.

 

Hope that helps.

[Yuk Hoy Cheong]

Hello Mike,

 

Yes! I'm having problems when going higher frame rates. I will definitely try your suggestion of using the Hytron 140 with either the Dionic 90 or the Trimpac combination to power the 435. And as a fall back plan, starting the 435 at 25fps and then switching to the higher frame rates.

 

Are you using just the Hytron 50's, or any other combinations for your battery power set-up?

 

Thanks for your help. Appreciate it very much.

 

Cheerio

cheong

[Alec Jarnagin SOC]

Cheong,

 

I'm surprised you had troubles with a NiCad battery in the mix (the Trimpac). New Dionics should have been okay too, but a Dionic 90 and a Trimpac in Series should have performed well.

 

Here is a wattage chart from Anton Bauer:

 

http://antonbauer.com/selecting_batteries.htm

 

I think they are not giving the Trimpac enough credit here though as they list it below all the others (except the Hytron 50) in terms of maximum load.

 

While I have the utmost respect for Mike, I'm not a fan of Hytron 50s. Not enough watt hours to justify its limited load capacity - I think the Dionics are a much better choice (come on Mike, make the switch - you'll love em).

 

Another tip, if you are using the 435 Advanced or Extreme go into the menus and set the camera to "slow start up" (or something like that). This brings the camera up to speed a bit slower and therefore decreased the amperage and gives your batteries a fighting chance.

 

Also, ambient temperature plays a roll. If very cold out, you'll have more problems (guess you don't get much cold weather down your way Mike).

[Yuk Hoy Cheong]

Hi! Alec,

 

I was dumb founded when it happened. I had thought that I had all my bases covered when I decided to have the combinations of battery set-up. Looks like I still need more research on this. I wonder if Paul Dudeck could enlighten us here.

 

Thanks for the tip on the menu set-up in the 435 Advance and Extreme. Will surely work on that one.

 

Would the temperature and humidity affect the Batteries? It is definitely hot and humid where I live.

 

Many thanks for your tips

 

Cheers

cheong

[Mike McGowan SOC]

I didn't know about the slow start option in the menu, I'll have to check that out.

 

As for switching, I'm a big, "if it aint broke don't fix it" guy. The day I start to think those Hytron 50's suck, I'll loose them faster than an ugly blind date.... But, as long as they keep kicking super big bootie for me, I'm a Hytron 50 man!

 

Are the Dionic's Lithiom or NiCad? I like the travel friendlyness of the 50's........ Also, the cost, the 50's are super cheap, how about the dionics???

[Alec Jarnagin SOC]

"Are the Dionic's Lithiom or NiCad? I like the travel friendlyness of the 50's........ Also, the cost, the 50's are super cheap, how about the dionics???"

 

You got me there Mike. The Dionics are Lithium Ion (but each battery is under the limit - still some restrictions, but they are legal to fly with) and more expensive than the Hytron 50s.

 

Regarding the slow start up; I should add I've never needed to mess with that so I have not actually done it. I've read/been told that it is an option in the later models of the 435. You should ask Arri about it (in case it is not a menu but a factory setting - I'm virtually positive it is a menu which is why I stated that above).

 

Cheong, something else occurs to me. What sled are you flying? Mike and I have PRO 2s and I think we were assuming you did as well, but the gauge of your cable running up the post, etc is a factor too.

[Ramon Engle]

Cheong, something else occurs to me. What sled are you flying? Mike and I have PRO 2s and I think we were assuming you did as well, but the gauge of your cable running up the post, etc is a factor too.

 

Gentlemen, Arriflex suggests that a 14 gauge cable be used to supply power to the camera. So if the combo of an underguaged cable in the post and from the sled to the camera you could experience your situation. I've been able to run a 435 at 120fps on my nexus sled using 2 dionic 90's and a hytron 140. Using the same batteries in the AR setup I couldn't turn over the camera at all! In the AR configuration I have to use a camera power cable extension. The gauge of those cables was 22. I made a 6', 14 gauge camera power cable. I'll let you know if that solves my problem. I've yet to test it.

 

Cheong, good luck with the 435. Its a real power hog.

You've got to luv the 235!

[Yuk Hoy Cheong]

Hi! Guys,

 

Sorry for the late reply, was on a job flying with the 535B. This time no problems running at 24fps with the same combination of Trimpac and Dionic 90 powering it.

 

I am not as lucky as you bigger boys as to having the PRO 2's and the likes of it and also enough of work to go by. Where I come from there's hardly enough work for any of those high end investment for Steadicams. There is hardly any returns, there is still so much work to be done to educate the local producers as to put aside an amount for Steadicam to be included in their equipment package. I am having the ActionCam - Zero-G at the moment.

 

As for the gauge of the cable, I do not know but I am finding out. Yeah, that could also be the case but I am sure Brian (ActionCam) is professional enough to put in a decent cable.

 

Will hit the rental house next week to try out all you guys' suggestions. Thanks for all the help and suggestions. Have a great weekend ahead.

 

Cheers

cheong

[Imran Naqvi]

Couple of questions, how old are your batteries?

 

Did you buy new? Or have these been recelled?

 

Do they live on the charger when not is use?

[Yuk Hoy Cheong]

Hello Imran,

 

All the AB batteries and the two dual chargers are new, about five months old and since I had seven batteries and two dual chargers, they sit on the chargers every other day when not in used.

 

Thanks for what-ever light you can shed on this.

 

Regards

cheong

[Imran Naqvi]

The only thing I can suggest it to check your outputs with a voltmeter.

 

If you're getting correct volts out of the ports, then check the pins on your power cables once they're plugged into the rig with fresh batteries. It does sound like you're getting a voltage drop somewhere.

[Yuk Hoy Cheong]

Hi! Imran,

 

I will check the next time I power up my rig. So what can one do if there's a voltage drop, what steps can one take to rectify the problem?

 

Thanks again for the interest shown.

 

Cheerio

cheong

[Jess Haas SOC]

I think they are not giving the Trimpac enough credit here though as they list it below all the others (except the Hytron 50) in terms of maximum load.

I believe the chart is correct because they are talking about continuous load and our concern here is the peak load during camera start. Trimpacs use smaller cells than the other AB NiCads and as such can't handle as much current. That being said when it comes to short durations such as when starting a camera they should be able to handle a higher peak load than an equivalently rated lithium ion(dionic) or NiMh(Hytron).

 

I think that the cabling could be a factor here. I would love to hear from Brian about what gauge wire the Zero-G uses. I wouldn't be too surprised with it being a smaller gauge which would be contributing to your problem.

 

~Jess

[Eric Fletcher S.O.C.]

I'll post this again, it's a good primer of what's going on in our rigs when it comes to power.

 

22 AWG wire is rated at 7 amps in clear air. That means NOT next to another wire, which is something that we all ignore. if we actually paid attention to that it would mean a current capacity of only 4.6 amps and that will power a film camera, well not a 435 but the rest of them. It will NOT safely power a F900, Viper, Genesis or F23 since they are all 9+ amp cameras.

 

20 AWG is rated at 11 amps in clear air or 6.6 amps in a cable pair/bundle. Still Not enough to power a HD camera.

 

XCS uses 14AWG Wire in their post which will carry 32 amps free air or 19.2 amps in a cable pair/bundle. Tiffen is also using 14awg in the U2. Pro is using 20AWG wire, MK-V and Actioncam use 22awg and they have some other serious power issues due to voltage drop.

 

Voltage drop goes up with length of the cable run. That cable run is the length of the post cable plus the camera power cable. in a Pro with the standard post that's around 65" but voltage drop is round trip so it's a ~11ft run. For the sake of argument let's use the maximum current capacity of each wire size to figure out voltage drop. For the 22awg wire you are looking at a 4% or 1 Volt Drop. the 20awg wire will see a 3.5% or .8volt drop.

 

Lets look at 2 XCS center post's the Fixed and the expandable. The fixed post has a 6' round trip and the expandable has a 12' round trip. the Fixed Voltage drop is 2.75% or .3 volts. the expandable has a 5.5% or .6 volt drop

 

The U2 is going to have a 6.64% or .797 volts.

 

MK-V has an internal cable run of 9 feet on the four section post with it's 22awg wiring suffers a whopping 11.5% or 1.4 volt drop.

 

What does this mean? Since HD cameras are the the worst case scenario for voltage with their 11 volt shutdown, it means MK-V will shut down first even though the battery is showing 12.4 volts, Followed by the Pro at 12 volts the U2 at 11.8 and the XCS at 11.3

 

The Dangers of Powering a HD camera on a 22AWG wire is that the resistance goes up on the wire with temperature, and as you pull more than rated amps you increase the wires skin effect which increases the temp which increases the resistance which increases the voltage drop which increase the amp load... and that increase the wires skin effect which increases the temp which increases the resistance which increases the voltage drop which increase the amp load, and on, and on, and on. It's called a cascade failure. (It's also why NiMH battery chemistry is so bad same thing happens)

 

In the end you CAN power the HD camera off the smaller wire but you will have to accept the shorter battery life.

 

I had a Pro II with the MK-V center post conversion and when I did a long show with a Genesis the rapid battery depletion was killing us, that's what prompted my change over to XCS.