So I figured I'd try to put together a nice kit for portable power for my strobes. Sometimes I wish for more power for outdoor family photos than my speedlites can provide. I have a mix of D-Lite4 and Elinchrom BX500Ri units. I only need ONE light for my outdoor shoots.
So I looked into the Tronix Explorer XT. Looks awesome... but too big for my preference and pretty heavy at 18 lbs. Not something I want to lug.
Looked into the Vagabond 2. Looked better to me than the XT, but still too big for my preferences, and still way too heavy at 18.6 lbs.
With the prices of these units, cost was not a factor. I wanted smaller and lighter more than anything else. My shoots are short so I do not need to be able to blast off 800 full power flashes. All I need is about 150 at the most. So it didn't make sense to me to carry all this extra weight for power reserves that I just don't need.
So I hacked my own setup. Butt ugly but works.
I used the Professional-grade Samlex/Cotek SK350-112 pure sine inverter. I bought it from donrowe.com here for $229:
http://www.donrowe.com/inverters/sk_350.html
It provides a continuous 350W and a surge of 700W.
I was going to use the much cheaper ($159) Samlex PST-30S-12, but I figured I wanted the tougher build and extra surge wattage, since recharging a strobe will pretty much put these things into surge wattage territory. Like I said, price is not my main concern. But I'm sure this cheaper one would perform just fine too:
http://www.donrowe.com/inverters/puresine_300.html
Bought a 7Ah SLA battery. $20. Smart SLA charger bought for $40.
Attached them together with some flat aluminum and anti-slip foam, bolted an aluminum door handle to it for carrying.
Yeah! I love ghetto hacks!
The 'business' side:
Weighed it on my (supposedly) super accurate kitchen scale. 3.863kg!! (which is 8.5lbs for your Americans) Now THIS is a weight range I can see myself lugging around. TEN pounds lighter than the Vagabond 2. Less than half the weight of the Tronix Explorer XT.
Equally as important was the overall size. It's not very big at all. Here it is next to a camera for comparison:
So how well does it work?
I first tried plugging it into a BX500Ri. I wasn't too optimistic on this but it kinda worked. Charging time was rather slow... and it would beep a few warnings or something every time I tried to charge up 100%. If I turned the power down a bit, it seemed to work ok, but it didn't seem all that happy.
I measured the AC voltage drop during full power recycling. At idle, voltage was normal and steady. Recycling from a full power blast, the AC voltage drop went down to the 85V area. It didn't seem to like the voltage going that low, which is unsurprising as it's rated to work only at 90V or higher. I figured this is the reason the Explorer uses dual 7Ah batteries, and the Vagabond uses a BIG battery... to reduce the load resistance of the circuit and therefore have less of a voltage drop (in addition to providing more pops per charge). My small battery probably falls below the acceptable threshold for a larger-scale production product for mass compatibility.
But I'm not designing for mass-compatibility. I'm designing for Lloyd-Compatibility.
So I hooked it up to my D-Lite4.
This setup loves the D-Lite4. Recycle time is very very close to mains power. AC Voltage drop is a little smaller at just over 90V. There are no warning beeps going off during a full power recharge from the strobe. BUT... with each pop, the low voltage warning beeps start going off from the INVERTER. The DC voltage drop goes down to about 10.7V during recycle. The inverter spec is to give warning beeps if the input voltage drops below 11V. It doesn't seem to affect the performance though. It recycles beautifully and works really well!
I never did a pop test to see how many blasts the battery will give me, but I've shot about 80 full power shots on one charge and there didn't seem to be any loss in performance up to that point. So it will definitely keep me happy on my relatively short shoots. I looked into smaller SLA batteries, but the internal resistance ratings of the smaller batteries were getting too high, considering the voltage drop to 10.7V was already really close to the 10.5V shutdown threshold of the inverter.
It works really really well for *me*. I don't see myself using it THAT often (I'm still a speedlite junkie) and I don't need to take too many strobed photos for a typical outdoor shoot.
Here is a little family shot taken with the power pack, D-Lite4 at full power, and a small 24"x36" softbox. ISO100 1/250 F/11:
Overall I'm quite happy with it. If I get a sudden influx of unexpected cash, I'd get a Profoto AcuteB setup, but this is working really well for me.
