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DC Battery Solutions for Lighting


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Hello,

Usually I'm operating lights only with AC. But want to be prepared for mobile applications requiring more DC power

The lights I often come across have DC ranges from 14.4v, 26v, 48v (I think the skypanels are the only ones that use 48?, but usually powered by 26v bricks and the plate has a transformer?? If that's the case that's interesting because I didn't know a transformer could double the voltage like that)

Basically, what's the most common DC solutions available? AB has a larger brick solution, the Cine VCLX to switch voltage. I like solutions like this because it means it will be more universal and more WH. Block battery seems to market similar solutions but heavier and larger WH.
https://blockbattery.com/block-batteries/

So far I'm liking the block batteries, but wanted to hear any other user's thoughts. Additionally, it'd be really cool to get a super high WH solution with an inverter, to power larger wattage 120v AC only lights...like a j800. Any precautions there?

I would also like to see if anyone DIY'd a bunch of deep cell batteries and inverter to a dolly and would like to see their build!

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Block batteries are going to be your best bet for consistency, build quality, and connectivity.

I've used a string of AA batteries to power a Litemat, but it wouldn't last too long.

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I don't know the inner working of those regulated 48V DC batteries, but I don't suspect that a step-up transformer is utilized, as they're rather heavy, expensive, and are not regulated. The two batteries are likely run in series to combine their voltage, and then regulated through a boost and buck DC-DC converter. Doesn't really answer your question, but I couldn't help it. 

As for running an 800W HMI off of battery, the necessary warm-up time for an HMI might really chew into any operating time that the battery could supply. Short of buying or renting a voltstack, I don't know. If someone has a recommendation, I would also love to hear about it!

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Transformers don't work on DC; transformers are an AC thing. Any device designed to increase the voltage of a DC power supply is simply termed a DC to DC converter. While very large DC converters in the multi-hundred-watt range do exist, it is likely to be cheaper and more efficient to use batteries in series in the circumstances that exist in filmmaking.

Mains loads in the kilowatt range can absolutely be run from batteries via an inverter, although beyond about 500W it's likely to become a stack of equipment that requires a cart to move around and quickly becomes more hassle than any reasonable amount of mains cable. Special circumstances might exist that make it worthwhile, of course. I once consulted on the creation of a cased inverter and battery combination designed to run a smoke machine with a 1000W peak consumption, although that peak is only reached when the heater is on. We designed it around a 48 volt DC bus which therefore peaks at a little over 20 amps. It uses lead acid batteries which work but it is very, very heavy; money can offset that by using more advanced batteries, which also require more advanced chargers.

The electrical hazards of high current DC devices should not be overlooked; it might not be enough volts to sting (though you will feel 48 in the right conditions) but the fire and arc flash hazards are very real. A member of my family was once hospitalised by an arc flash accident while configuring lead acid battery banks.

P

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On 4/2/2020 at 10:03 AM, Joseph Tese said:

...it'd be really cool to get a super high WH solution with an inverter, to power larger wattage 120v AC only lights...like a j800. Any precautions there? I would also like to see if anyone DIY'd a bunch of deep cell batteries and inverter to a dolly and would like to see their build!

To power a small HMI off of batteries for an unlimited time in a car rig you can use a "Battverter" - which is a Battery/Inverter system. A "Battverter" system consists of a 12V DC power source (usually large Marine Cells), a DC-to–AC True Sine Wave Power Inverter, and a Battery Charger.  Here is a link to some production stills that show you two Battverter systems I built to run lights in vehicles at various times. The first is a 750W "Battverter" rig wired into a Calzone case. The second is a more elaborate 1800W Battverter system that I built to run 16 - 4’ kinos tubes inside an airport shuttle bus. Use this link - https://cinematography.com/index.php?/topic/70937-indie-tricks-of-the-trade-or-how-to-get-good-production-values-on-a-modest-budget/- for details.

Guy Holt,  Gaffer, ScreenLight & Grip, Lighting Rental & Sales in Boson

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Just an FYI on block batteries:

 

Block Battery S600 Battery About 2 hours Plus of run time on Skypanel S60 (Skypanel runs at 1/2 power)
 
Block Battery S600 Battery 48Volt Adaptor for Skypanels About 60 Plus minutes of run time for Skypanel S60(At full power) S600 Battery required.
 
Block Battery 2F1 (2) with 28.8 Volt adaptor About 35-40 minutes of run time (Skypanel runs at 1/2 power) 
 

Block Battery 2F1 Battery Belt About 50 to 60 minutes of run time (Skypanel runs at 1/2 power)


http://www.woodennickellighting.com/Public/rental/lightingrentalpackageframe.html

 

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Other options 

Goal Zero Yeti 1400 Lithium pricey though @  $1,800.00

Great option for LED lighting
- Has a LED display showing remaining time to battery "runs out"
 
Will run a 
-SkyPanel s-60 for about 2.5 hours  @ Max Power(Plus or Minus)
- SkyPanel s-30 for about 5 house @ Max Power (Plus or Minus)
- Kino Flo Select 30 for about 15 Hours
- LiteGear LiteMat for 6+ hours
 
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On 4/3/2020 at 5:19 PM, AJ Young said:

I think we strung together 8 of them for a litemat 1? It was, oh man, almost five years ago now. ?

Non-rechargeable AA cells are typically 1.5V, so eight would give you 12V.

Nickel metal hydride rechargeable cells are 1.2V, so 10 would give you 12V. 

In either case you might aim slightly higher than 12, to provide for better runtime; naturally, observe the limits of the device you're powering.

Sprung-contact battery holders are very bad at passing lots of current, so this is not a great way to go for large loads, even with big D cells.

P

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On 4/6/2020 at 2:49 PM, Phil Rhodes said:

Non-rechargeable AA cells are typically 1.5V, so eight would give you 12V.

Nickel metal hydride rechargeable cells are 1.2V, so 10 would give you 12V. 

In either case you might aim slightly higher than 12, to provide for better runtime; naturally, observe the limits of the device you're powering.

Sprung-contact battery holders are very bad at passing lots of current, so this is not a great way to go for large loads, even with big D cells.

P

That's good to know, thank you!

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  • 2 weeks later...

I've run a couple hundred watts using an inverter on a car jump start battery.  Not elegant but it works and it's cheap.   There are some "power packs" that are big batteries with inverter built in.  

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