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-   -   Are sealed lead acid batteries any good? (https://www.dvinfo.net/forum/photon-management/6421-sealed-lead-acid-batteries-any-good.html)

Marco Leavitt January 28th, 2003 02:47 PM

Are sealed lead acid batteries any good?
 
Can someone tell me the pros and cons of this type of battery for powering an on camera light? They seem to be really cheap. How long would a 12v, 14.4 amp hour battery power a 100 watt light?

Don Bloom January 28th, 2003 03:18 PM

I can't say for sure how long but I use a Bescor 50W with a Bescor juice box that goes about 75-90 minute depending on how much on/off and a Bescor belt w/2 batteries that goes around 21/2 hours. More than enough to do a complete wedding reception. The downside is they are heavy batteries! However in the Chicagoland area that sometimes works out well especially for guys like me who aren't as big as some others! Also I always charge them up (as I do all my batteries) the night before a shoot. You never really know how much juice is left in them.
Don

Dean Sensui January 29th, 2003 04:51 PM

These pack quite a bit of power in an inexpensive package, and they can tolerate fairly high amperage loads. Backup power supplies use them.

You could make a rough guess at how long they might run under a particular load. A 12-volt, 100-watt lamp draws 8.3 amps (power = amps x volts). Theoretically, a 14.4 ampere-hour battery might be expected to run 1 hour and 40 minutes (14.4 ampere-hours divided by 8.3 amps).

Of course it's not quite as simple as this as battery capacity depends on the nature of the load, chemistry, battery condition, temperature and where a device's performance is no longer considered acceptable.

Dean Sensui
Base Two Productions

Imran Zaidi January 30th, 2003 08:37 AM

Question.... aren't sealed lead acid batteries basically what car batteries are? Don't know too much about field lighting and batteries, but I'm just curious.

I do know that running a car battery down to zero and then recharging it reduces its life significantly over a normal vehicle situation where the alternator keeps recharging it without ever letting it get to zero.

I know this isn't an auto discussion forum. It just got me wondering about cheap possibilities for lighting on the run...

Don Bloom January 30th, 2003 10:34 AM

Yeah, I guess thats pretty close. I can tell you that I have never run down either battery to dead. If I'm using the juice box, I figure I've got about 1 hr to 1 hr and 15 mins (lite on/off/on/off etc.) then it's done. The belt, well if it goes a total of 11/2 hours at a wedding reception, then thats a lot, so I never get to the point of complete discharge on that either.
Don

Jeff Donald January 30th, 2003 08:39 PM

The advantage of lead acid is none of the alleged memory effect of Ni-Cds. The recommended charging of Ni-Cds (to prevent the memory effect) was to drain completely, then recharge to a full charge. Lead acid batteries do not have a memory effect. Just like the battery in your car, keep your lead acid batteries charged all the time. Storing them in a partial, or completely discharged state decreases their overall life (number of total discharge-recharge cycles).

Dan Holly January 30th, 2003 10:31 PM

try this......
 
Gentlemen,
Try this out.........we have this setup for lighting on one of our boats. It works perfectly, and takes the worries out of what everyone is talking about above. If you do the math below, it's 34 cents ($0.34) per discharge. IMO, you can't beat the cost/discharge price of these type batteries.

I realize that everyone doesn't have the "application need" that we do, so just use a freight dolly with a marine battery box type cover to protect it (or whatever that meets your application needs).

Cut and pasted from www.cabelas.com

Optima Batteries (one version is $119.00)
These batteries provide clean, reliable power and great cranking ability with life spans two to three times longer than the competition. They can be fully recharged in as little as one hour - half the time it takes other batteries. Spiral-cell design resists jarring and vibration, and eliminates plate shedding, the leading cause of failure in Flat Plate Deep-Cycle Batteries. Tested to exceed 350 complete discharges - outcycling conventional batteries by up to three times. Slow discharge rates means your battery can sit for a year and still start your boat. Completely leak and spill-proof, they come with a one-year warranty. New Troll Fury combines two deep 900m into one convenient package. Can be wired for 12V or 24V.

Marco Leavitt January 31st, 2003 08:18 AM

These batteries sure look like they put out a lot of juice, but good lord -- 38 to 90 pounds? And people complain about how heavy the XL1 is. :)

Don Parrish February 2nd, 2003 07:58 AM

I have used a lead acid battery since I first began buying my equipment, and I too had a lot of worries about carrying around this type of battery. 16 months later the batteries are still fine. Are far as cycling goes, the price for a lead acid battery pack vs ni-cad means you can buy 3 or 4 lead acids for the price of one ni-cad and not worry about memory. The lead acids have never dimmed on me but admittedly 45 minutes or so has been my longest shoot. I use an NRG variable power light that can be both bright for distance and dim for interviews. I dont know about the ni-cad but the lead acid bescors can have both XLR and cigarette lighter connections meaning that you can discharge the battery and then connect to your vehicle's cigarette lighter to charge it up. I also can use the cigarette connection in a pinch to run other equipment, scanners etc. Mine are in a belt that has two 1"x3"x5" batteries. The belt is not comfortable enough to be worn around the waist, I usually sling it over my shoulder or use it to weight my tripod down for camera safety. Great bang for the buck, just wish I could find a trustworthy voltage regulator that could cut the voltage down to run the camera also, it would be great to have that much power available for disasters when your shooting for hours or when your shooting in the wilderness. I have learned to shut it off when not in use.

Jeff Donald February 2nd, 2003 08:18 AM

Don,

NRG makes an adapter to convert between 9 and 16 volts to 7.2 volts required for the XL1. They aren't cheap, but they do the job.

Don Parrish February 2nd, 2003 08:31 AM

Thanks Jeff, these belts provide a tremendous amount of power compared to a camera battery. Would you have any concerns using the adapter? Having them adapted as a camera battery would give me protection for those news stories where your running your tale off and shooting some unexpected event. (they are also great at night when your lost in the forrest :).

Jeff Donald February 2nd, 2003 08:36 AM

NRG equipment has an excellent reputation for reliability and workmanship. I've owned their belts for many years and have been 100% satisfied with their performance. The convertor, voltage adapter is not a tricky circuit. I'm sure it's safe for the camera and belt.


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