My turn for a nasty DIY battery powerpack hackjob

[picturecrazy]

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!

http://www.nightanddayphoto.ca/misc/forumpics/POTN/powerpack/pack1.JPG

The 'business' side:
http://www.nightanddayphoto.ca/misc/forumpics/POTN/powerpack/pack2.JPG

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.

http://www.nightanddayphoto.ca/misc/forumpics/POTN/powerpack/pack3.JPG

Equally as important was the overall size. It's not very big at all. Here it is next to a camera for comparison:

http://www.nightanddayphoto.ca/misc/forumpics/POTN/powerpack/pack4.JPG


http://www.nightanddayphoto.ca/misc/forumpics/POTN/powerpack/pack5.JPG

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:

http://www.nightanddayphoto.ca/misc/forumpics/POTN/powerpack/pack6.jpg

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.

[tim]

Nice hack! I suggest you take out the annoying speaker to stop it beeping :)

[SYS]

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.

The bottomline: what works for you and makes you happy! Nice job. I'm surprised how small it is. :)

[picturecrazy]

Nice hack! I suggest you take out the annoying speaker to stop it beeping :)

LOL... I thought about it, but then again, if anything ELSE went wrong, I'd have no warning. hahaha

The bottomline: what works for you and makes you happy! Nice job. I'm surprised how small it is. :)

thanks. Yeah, I'm all about convenience and the small form factor. I figure the easier it is to lug, the higher the probability that I'd actually want to use it.

[bobbyz]

Why not get vagabond and change the battery? I have heard that it can be done easily but I haven't tried it myself. Being handicapped I am also looking for lower weight options.

[fashioneyes]

Nice job.

I'm interested in doing something similar and not quite understanding the principles behind prompts the following question:

Why do I need a pure sine inverter ?

There are other inverters that I've seen that are approx 50% of the price of the pure sine wave ones ... will these not do the job ?

[picturecrazy]

No, you NEED a pure sine inverter. Most precision electronics require a pure sine inverter. For a better description... see here:
http://www.donrowe.com/inverters/inverter_faq.html#modified

I know the price of the modified sine inverters are tempting, but it just won't work.

[Big Mike]

Very interesting, nice work on the DIY Lloyd.

[picturecrazy]

Thanks mike. I was wondering if you had portable power for your bees. Do you have a vagabond or something like that?

[Big Mike]

No I don't...but I've considered the Vagabond.

I wonder if your set up would work well with the Bees...

[picturecrazy]

you are welcome to take it out for your next shoot! I'd like to know if it works too. :)

[Marloon]

how did you get that EF-S 10-22 on a 1d body?

[Johnny V]

Cool Idea....it's so ghetto that it looks dang cool!

[PKSmith]

+1 on a EF-S on a 1D?

[tim]

how did you get that EF-S 10-22 on a 1d body?

I vaguely remember Lloyd using a hacksaw or something!

[picturecrazy]

Cool Idea....it's so ghetto that it looks dang cool!

Hahaha i love ghetto. Ghetto stuff that actually works well is the shiznit. :lol:

I vaguely remember Lloyd using a hacksaw or something!

LOL. Just replace the EF-S baffle with an EF baffle and it will mount onto any EOS body. I love using it with my 1D3 and 1Ds3. The last family shot in my first post of this thread was taken with the 1Ds3 with the 10-22. It works around 15mm without vignetting.

[Big Mike]

For anyone who cares, Lloyd graciously allowed me to borrow his ghetto contraption and it worked perfectly with one of my B800s. I didn't try to push the limits though, I kept the light set to about 1/4 power....but it worked just as if it was plugged in to an AC outlet.
If I recall correctly, it only gave me warning beeps when I was rapid shooting near the end of the session.

I'm already starting to build my own version.

Thanks Lloyd :)

[blam]

wow, i wish i saw this before buying my vegabond. lol

[picturecrazy]

Glad it worked out for you Mike. I'll have to check out your setup when you put it together. Brian, you'll have to let us know if your vagabond works with your two D-Lites. I know mine for sure will only work with one D-Lite.

[Vascilli]

Hahaha i love ghetto. Ghetto stuff that actually works well is the shiznit. :lol:



LOL. Just replace the EF-S baffle with an EF baffle and it will mount onto any EOS body. I love using it with my 1D3 and 1Ds3. The last family shot in my first post of this thread was taken with the 1Ds3 with the 10-22. It works around 15mm without vignetting.
On a APS-H body (1D) you can use it at around 12-13mm and up with little vignetting. (Any wider and the mirror hits the rear element)

This looks like a good price to get some portable power, maybe I'll have to try this sometime. :)

[blam]

Lloyd, it works fine with 2 D-lites even on full power.

i leave the modelling lights off however, especially since the fans are running full time. I haven't had much time to really test them though due to weather and some personal stuff.

[Wilt]

Might TWO SLA batteries, in parallel, resolve the beeping?

[picturecrazy]

Might TWO SLA batteries, in parallel, resolve the beeping?

Yes, it probably would as it would effectively HALVE the internal resistance of the power source which would yield a lower voltage drop under surge load. I believe this is exactly what the Tronix explorer XT does.

But if I wanted something that big and heavy, I would have just bought the Explorer XT. But I wanted something small and very light compared to what's out there.

If you mean use two batteries of half the capacity, it wouldn't really give much benefit as it'll *typically* yield approximately the same internal resistance as one of double the capacity.

[Wilt]

Yes, it probably would as it would effectively HALVE the internal resistance of the power source which would yield a lower voltage drop under surge load. I believe this is exactly what the Tronix explorer XT does.

But if I wanted something that big and heavy, I would have just bought the Explorer XT. But I wanted something small and very light compared to what's out there.

If you mean use two batteries of half the capacity, it wouldn't really give much benefit as it'll *typically* yield approximately the same internal resistance as one of double the capacity.

Proves 'no such thing as a free lunch'!

[Big Mike]

I assume I could just swap over to a larger battery (say like a car battery) if I wanted more juice and didn't mind the weight?

[picturecrazy]

Proves 'no such thing as a free lunch'!

Yeah, I WISH! Then I'd have a 2lb portable powerpack! :)


I assume I could just swap over to a larger battery (say like a car battery) if I wanted more juice and didn't mind the weight?

Yes, you totally can do that, though I'd try to find a deep cycle battery for the job. Car batteries are not deep cycle, but can definitely be used in a pinch. But not something I'd get for a dedicated setup.

The larger batteries will also have less internal resistance so it might work even better. It's all a balance of what you need. Weight vs number of pops. weight vs voltage drop. wattage vs desired recycle time. etc...
The 7ah battery was my happy place.

[blam]

something you might consider, Lloyd, for a carrying case is a lunchbox.

I skipped on buying the vegabond carrying case as the total cost was 40USD less without it.

I went to walmart and got a large lunchbox/cooler that fits the unit perfectly. for ~15$ not 100% sure on the price anymore as it was actually my lunchbox for work i purchased 2 years ago.

[Big Mike]

I got my inverter today. It's about the same size as Lloyd's, maybe a touch bigger. I was hoping it would be a little smaller. It feels lighter, although Lloyd's had the bracket & handle attached to it.
If this one hadn't been on sale, I would probably have opted for the same one that Lloyd has. His has two outlets and it's a GFI outlet. Plus, it's got better connectors (plastic plugs). Mine has the straight socket with a set screw.

[The Fox]

That is cool, but Vagabonds cost ~$10 more and has 15Ah battery, a nice case and is heavier. This puts out a little more wattage, 350 vs 335 for the vagabond.

I love the idea, but it cost too much for me personally to use it against my vagabond.

I did see a guy with one like this, but he had a 200Ah battery with a 1500watt inverter on it, now that was one hell of a powerful pack.
Nick

[blam]

The Fox, the 3 of us (me, big mike and lloyd) live in canada, add $70USD shipping and multiply by ~1.2 for the exchange rate.

[The Fox]

Then that makes it worth it.
Nick

[Big Mike]

That is cool, but Vagabonds cost ~$10 more and has 15Ah battery, a nice case and is heavier
This was the whole issue to start with....the Vagabond is just too heavy (for Lloyd anyway, he's a lightweight ;) )

The beauty of this little kit is that it can be attached right to your light stand. Then you can just pick up the whole unit (battery, stand & light) all in one and place it as needed or carry it to your next location. This is especially useful when you have a camera in your other hand and a camera back slung over your shoulder (or vice versa).

For me (and probably Lloyd as well) there was also a little bit of 'do-it-yourself-ish-ness' involved...just wanting to see if we could build it and make it work.

Overall, I'd probably recommend the Vagabond to people, rather than doing it yourself...but as blam mentioned, we Canadians sometimes have to be more creative because of the additional costs of ordering things from across the border.

[The Fox]

I like the weight, it means that I can crank my 47" octabox with a x1600 13' into the air.
I completely understand about ordering things that will cost a small fortune because of exchange rates, and international shipping.
Nick

[ueb0258]

Just a little FYI. I have one of these I built myself a while back. The beep while recycling is not a good thing. If it is short it shouldnt cause a problem but while I was building mine another person on here was doing the same a contacting Samlex about the beep. When it beeps due to low voltage it actually converts from pure sine over to a modified sine wave. Like I said probably not bad if it is short beep but if it starts getting longer you could possibly damage your equipment. Just throwing out a little info.

I love mine. I can use 3 Photogenic StudioMax 320ws at full power and dont get a beep with a 25Ah battery. On the other hand I get a beep when trying to power my PL06 600ws light. It is an older light and might be less efficient than my 320's but it only has a short beep and I need to try it with heavier gauge wiring from batt to inverter.

[Johnny V]

ueb0258... have any picks of your setup?

[ueb0258]

No real setup I just carry the battery and the unit and hook it up when I get where I am going. So far have not needed to cary it a long way so no really need for bag but I am going to pick up the replacement bag from Alienbees V1 since they are local to me. I actually used to work around the corner from their shop.

[Big Mike]

I just want to mention how disappointed I am with the input connections on my Samlex inverter. It's basically a tube connection with a set screw (which requires a precision size screwdriver...another fault IMO) Their included cables have the proper pin type male connector on them but my problem is that in trying to make up battery wires, I can't find similar pin type connectors. I've been to every hardware store and a few electrical supply stores...nobody has them.

I've managed to take a male bullet type connector (10-12ga) and squash it enough so that it fits...but I'm thinking that this would then be the bottleneck in the circuit. I could just twist the wire end and put that in...but that's not idea and it says right in the instructions not to do that.

I'm thinking that I will cut the ends off of the included cables and put a connector on the end of a short wire. Then put matching connectors on my battery leads. PITA but I just can't find a simple pin type connector.

I guess another option would be to take the inverter apart and change out the input connectors...but I'm not sure if I'm up to that task.

[picturecrazy]

Hey Mike, that's what I did. I hacked off the ends of the included wire and crimped on some connectors to attach to the battery terminals.

hmmm, lunchbox huh? that's interesting. Though I'm trying to keep this as small as possible. As it is now, it's really easy to attach it to a light stand. It doubles as a sandbag! kill two birds with one stone!

[justincase724]

I've thought about this DIY project before too, but it was a light weight car battery (like this (http://www.braillebattery.com/index.php/batteries/b106c/#)) that I thought of using. I'm not sure if it would even be ideal to use, but I didn't go any further with it. Thanks for sharing your build though. I may do something like this in the future.

[ueb0258]

I just want to mention how disappointed I am with the input connections on my Samlex inverter. It's basically a tube connection with a set screw (which requires a precision size screwdriver...another fault IMO) Their included cables have the proper pin type male connector on them but my problem is that in trying to make up battery wires, I can't find similar pin type connectors. I've been to every hardware store and a few electrical supply stores...nobody has them.

I've managed to take a male bullet type connector (10-12ga) and squash it enough so that it fits...but I'm thinking that this would then be the bottleneck in the circuit. I could just twist the wire end and put that in...but that's not idea and it says right in the instructions not to do that.

I'm thinking that I will cut the ends off of the included cables and put a connector on the end of a short wire. Then put matching connectors on my battery leads. PITA but I just can't find a simple pin type connector.

I guess another option would be to take the inverter apart and change out the input connectors...but I'm not sure if I'm up to that task.

I took a look at mine tonight. I hadnt used it but with the jumper cables as of yet and hadnt really looked at the connector they used. If you ask me it looks like they took a male and female spade bit and attached the female to the wire and pushed the male in and crushed down the part that wraps around the wire without the wire in it. Throw on a piece of shrink wrap and it and I think that will give you want you are looking for.

[Johnny V]

Here's one with a car battery... cost around $1000 with all the parts:

http://www.flickr.com/photos/tonyd/2487365899/

[picturecrazy]

Here's one with a car battery... cost around $1000 with all the parts:

http://www.flickr.com/photos/tonyd/2487365899/

wow... exactly the opposite of what I wanted. Gigantic, huge, and very expensive!

But everyone has different needs I guess.