Pairing Monolights and Batteries

[hugebob]

<p>Hello All,<br>

What specifications should I look for when trying to pair a monolight with a battery so that I don't damage either one? If the lights have a certain Ws spec, what should the battery be rated at if I want x-number of full power flashes? Can battery size affect flash speed?<br>

Thanks!</p>

[Matt Laur]

<p>Before we get into the watts/capacity weeds - are you talking about large 12V (like sealed lead-acid, automotive or marine style) batteries to be used with an inverter to provide the monolight with 120VAC? Or are you talking about monolights that have a native DC input?<br /><br />If you're looking at inverters, be sure you're choosing one that will provide a continuous sine wave, rather than switched output, as the latter will quickly damage the monolights. But first, explain the larger situation so the conversation will make more topical sense.</p>

[hugebob]

<p>Hi Matt,<br>

<br />I meant the former: SLA's with an inverter. By native, do you mean the internal batteries for units like the Profoto B1?</p>

[ellis_vener_photography]

I have used both the Paul C. Buff, Inc. Vagabond Mini Lithium and Vagabond Extreme Lthoum battery /inverter

combinations without any problems with a few different MONOLIGHTS from Flashpoint, Bowens Gemini, and of course

the Paul C. Buff Einstein E640. I simply connect them to the MONOLIGHTS AC connection, and make sure the modelng

light is turned off and stays off.

 

What Matt is referring to are MONOLIGHTS that have a dedicated DC power connection for that brands external DC

power supply.

 

Which brand and model of monolghts are you asking about?

[studio460]

<p>I think the old Dynalite XP-1100 AC inverter/batteries are excellent values. Although discontinued, they can often be found on the used market for $400-$500. New, 17-amp hour, better-than-OEM, replacement batteries for the XP-1100 can be had for only about $120 (Enersys PC-680). These are SLA-based batteries and are super-easy to maintain. Dynalite now sells the Li-ion based XP800 for $999 (which appears to be a re-branded Godox).</p>

<p>Li-ions are more finicky than SLAs, and require you to store them at 50% power to maintain their maximum life. I've already killed two of my Paul C. Buff Vagabond Mini-Lithium batteries by not properly maintaining them (not always easy when you have multiple battery chemistries in inventory). The XP-1100s are heavy as heck (26 lbs.), but you get house-power like recycling times (<2 sec. for a 1,000Ws Speedotron monolight at full-power), and hundreds of full-power pops. I wrote a summary of AC inverters on my personal website here:</p>

<p>http://lightbasics.com/portable-power/</p>

[studio460]

<p>Robert said:</p>

<blockquote>

<p><em>What specifications should I look for when trying to pair a monolight with a battery so that I don't damage either one? If the lights have a certain Ws spec, what should the battery be rated at if I want x-number of full power flashes? Can battery size affect flash speed?</em></p>

</blockquote>

<p>I just realized I didn't actually answer any of your questions! The exact answers are likely beyond my technical expertise, but at least I can cite some examples. Most manufacturers will rate their inverters in terms of peak current supplied: e.g., "750-1,400W peak" for the Dynalite XP-800. Dynalite also states a recycle time example for their own strobe product: "1.4 sec. to full power with Dynalite MP800, 800W/s pack." If you're in the US, you can call Dynalite and ask about your specific strobe (I've spoken to Dynalite before, and they're very helpful).<br /> <br /> Paul C. Buff lists detailed capacity ratings for their own strobes for both of their inverters on their website, but most manufacturers do not. As a very general rule, the larger the inverter and its battery, the larger the strobe it can support, and the faster it will recycle that strobe. For example, powering my 1,000Ws Speedotron monolight from a Paul C. Buff Vagabond Mini-Lithium takes about 9 seconds to recycle. Such a long recycle leads me to believe that this is probably not the best match for the VML since continuous large current-draws may eventually negatively impact the longevity of its small, Li-ion battery (again, I'm not an engineer, so I'm just guessing here). But when powering my 1,000Ws monolight from my Dynalite XP-1100, recycle time is virtually identical to house-power (1.6 seconds). Also, since the XP-1100 uses deep-cycle SLAs, I believe they're inherently more well-adapted to large current draws.</p>

[studio460]

<p>By the way, there happens to be three Dynalite XP-1100s on eBay right now ranging from $350-$450 ("buy it now" price), I assume, based on varied cosmetic condition. They appear to be rental units from Samy's Camera in L.A. Even though the batteries are marked "good" in the photos, just assume you'll be buying new batteries. The Enersys PC-680 is a direct replacement for the OEM Genesis battery, and actually has a bit more capacity at 17 amp hours. The PC-680s are available from a ton of online battery suppliers for about $120 each. If you buy a replacement battery, you'll need to keep the Dynalite terminal posts and screw-downs from the original battery and attach them to your new Enersys.</p>

[hugebob]

<p>Ellis,<br>

I have an eye on the Broncolor Siros 400S or 800S. I'm drawn to their claimed HyperSync capability. Broncolor has an external power offering: the Powerbox 900. Its specs say:</p>

<ul data-selenium="highlightList">

<li >240 Full Power 300W/s Flashes</li>

<li >900W/s Capacity</li>

</ul>

<p>So, using either Siros at 400Ws or 800Ws, I'd be starting out below 240 full power (FP) flashes, correct? To calculate/estimate the number of FP flashes I'd be getting with a battery, is it as simple a matter of dividing the Ws rating of the monolight by the battery's FP flash rating? So, for example, a monolight rated at 600Ws using the Powerbox 900 would get 120 FP flashes from it. In the case of the Siros 800S, I'd be getting roughly 90 FP flashes (240*[300/800] = 90).<br>

<br>

Ralph,<br /><br>

The XP-800 looks good too. I wonder if you could connect more than one monolight to these units and apply the math above to see how many FP flashes you can get.<br /><br>

</p>

[bob_bill]

<p>If you are just starting to select your lights, consider more than just initial cost, consider the entire line of products that are supplied by the mfgr. It is the reason I use Einsteins. Great lights at a great price at the core of the system. Full range of reasonably priced modifiers or ability to use other manufacturers. Reasonably priced battery packs. I don't use any other studio strobes but theirs. The beauty of Einsteins is they don't have to be fully charged to pop if there is enough power for the exposure. I tend to keep my lights in tight so I get multiple burst shots on battery shooting them at my typical less than half power setting. Go with them and you won't find yourself jury rigging and hoping the mixture doesn't fry something. As for service, AB is flat amazing in this day of overseas help desks.</p>