Low Cost Portable Power - 300 watts under $250 -

[marknagel]

<p><u><strong>Low Cost Portable Power Source </strong></u></p>

<p>I posted a couple weeks ago about a low priced alternative portable power

supply.  I looked into the Alien Bee’s Vagabond, but at $500 for a

300 watt unit, I couldn’t justify it for the amount I’d use

it.  So I made my own.  Here’s my results:</p>

<p>First off, my background isn’t an electrical engineer, but I’m

pretty mechanical, pilot, by profession, own a cabinet shop, wired my cabin,

shop and my small home studio (I’m comfortable with a soldering iron)</p>

<p>Parts, I am using a 31amp deep cycle gel battery, Samlex 300 watt PURE sine

wave inverter (Vagabond uses the 150 watt Samlex), SV roller case, 10 ga. wire,

220v 20amp plug connectors, and ½” ply wood.  The battery was

$79, the inverter was $130, the charger was $30, and he wire/wood/connectors

was about $10.  The total invested was about $250.</p>

<p>I made a wood box to fit tightly in my SV roller case that can hold he power

unit, two Alien Bees strobes, and light stands and accessories.  The

battery is heavy, so the wheels case is handy.  The 31 amp battery (for

wheelchairs) is about 25lbs, yes that’s heavy, but its up to you to

weight the benefits of weight vs. number of flashes.</p>

<p>Assembly is straight forward.  I went to my home center and bought

several 220v 20 amp plugs.  Samlex recommends disconnecting the battery

from the inverter when not in use.  I used these because the high load

capability and they are unique plugs and won’t get accidentally used with

something else.  I made two accessory plugs, one for hooking the battery

to charger (while in box) and one for hooking the inverter to another battery

(spare battery is needed).  Note I hooked the female end to the battery to

avoid exposed prongs.  I also have an extra female end to protect the

prongs of the inverter end because the capacitors do store energy and can short

if exposed.  </p>

<p>After charging the battery, I tested the unit.  I got 200 flashes at

full power from both my Alien Bee 1600 and 800 (approx 960 w/s total).  I

did this over an hour time period and only stopped because I was getting

bored.  I put the battery charger on and it was reading about 60%, so not

too bad.  The recycle time is about 4 seconds for the two strobes at full

power and about 2-3 seconds with the 1600 alone.</p>

<p> </p>

<p><u><strong>Things to note:</strong></u></p>

<p>I bought (2) 300 watt inverters in hopes it would recycle faster.  It

did, but the rapid draw of two inverters would drop the battery voltage below

10.5volts during recycle and the inverters low voltage alarm would sound (loud

beep).  So I boxed the other one up and will list it on Ebay.  With

one inverter the battery is more than enough and the recycle times are close to

house.</p>

<p>Wire, I used 10ga wire for all the connectors.  This is more than

adequate.  I’ve seen other posts challenging this, but I upgraded

the power posts and the internal wiring is 12 ga. like the power chord of the

strobe.</p>

<p>Charging, I’d recommend a smart charger that prevents over charging

and ensures a full charge.  You can pick up a good smart charger for $30.</p>

<p> </p>

<p>Here’s a link to some pictures:</p>

<p><a

href="http://www.nagelhome.com/powerpack/">http://www.nagelhome.com/powerpack/</a></p>

<p> </p>

<p>Mark Nagel</p>

[phoneguy]

Very nicely done. Half price 300w inverter. Can't beat that.

[mikeseb]

Mark, very slick. Especially clever, using those 220v plugs. Safer, less resistance.

 

Did you look at the Innovatronix Tronix Explorer 1200 w-s portable power unit at http://

innovatronix.com/detailpage.asp?categoryid=42&productid=323&categoryname=Products%

20and%20Services ?

 

It would be about $300 shipped and unless I'm missing something it would do what your

system does, albeit without the fun of doing it yourself! :)

[marknagel]

Michael, the specs are a bit misleading on those units. They can handle a 1200 w/s monolight, but are not 1200 watt inverters, they have a 150 watt inverter and a 12 amp battery vs. my 300 watt inverter and 31 amp battery (1/2 recycle time and 2.5 times the flashes). Many have posted the recycle time is 4-8 seconds with a 600w/s strobe and about 250 flashes with those units.

 

If you want apples to apples, A DIY kit with a 150 watt inverter ($90), 12amp battery ($25), slow charger ($10), misc ($10) for a total of $135. This would be more comparable.

 

Mark

[mikeseb]

Mark, thanks for clearing me up! Where did you get the battery, the inverter, the charger, and the SV Roller case? (I googled the case but didn't turn up anything.)

 

Nice job.

[d_g5]

If you can find a great case for it and self contain everything and even make a 2 and 3 outlet version the only thing is getting 1 charger to chain to all and recharge all of them at the same time would be the real test. I actually have the Innovatronix Tronix Explorer system its pretty nice when it finally dies I'm gonna get a salamex battery and pop it in there to replace the one currently inside.

Is there a way you can put 2 batteries in a case with 2 outlets for power and a single charger that would recharge both at the same time? Can you to setup an led lighted powergauge like or better than the innovatronix tronix explorer 1200 (Green, Yellow, Red LED lights indicate power).

[marknagel]

Michael,

 

Sorry, SV is Smith Victor at Adorama, about $80 or so I had two of these already, I like the case because they hold the AB's perfectly. Battery and charger were at my local Batteries Plus. the inverter I found online and called to order it. I can't find the paper work, so I don't recall the website, I'll look.

 

dg,

 

Any case size is easy with wood, I wanted mine to fit in the SV case. I didn't enclose the inverter to allow better cooling. As for the two batteries, the one I used is 2.5x the amps of the tronix, so no need for another battery IMO. I plug in a 6 way power strip to mine. My smart charger can charge multiple batteries wired in parallel. As for the gauge, I think you could just go to radio shack and get a cheap voltmeter. Its considered dead when you hit 10.5 volts, so you just need to watch it. As I said, I hit 200 flashes full power with 960w/s and the battery was only 40% depleted.

 

Mark

[d_g5]

WOW... wait a minute! You put a 6 way power outlet on it! Thats how you got both the 600 watt AB1600 and the 300 watt AB800 to fire at the same time! Your da man! I read you loud and clear with the wood case idea and the item needing to cool... how much would you make and sell one for?

[d_g5]

how bout the case made only of wood then we find some sort of foam padding then cover it with a good nylon cover. Then we pop some removable wheeles! Man you got such a good thing you had better start makin up tons of em after a bit more test and ship it out with a 100% moneyback guarantee and make some great paperwork (manual and upkeep) on it!

[marknagel]

DG,

 

If you live in MN, we can get together and I can help you build it, but other than that, I don't plan on making/selling these, sorry. If you have access to a table saw, you can build one easy. The key is the inverter. I tried an AIMS 300 watt pure sine wave inverter and it did not work, not even with the AB800 alone. The Samlex is the way to go. It has no problem with the AB1600 and 800 together at full power.

 

I did plan on a stand alone box made of aluminum to double as a light stand weight, and still fit in the SV case, but my tig was out of gas and I was too lazy to fill it. Maybe in the future, I'll post if I do.

 

 

Mark

[d_g5]

Awwwww, I'm in Los Angles. Mind emailing me hwo to make it and where to order the parts from? I want to make 2.

[r._eric_summerfield]

I?m planning the same project, with about the same 900 ws load.

 

I was thinking a larger inverter would work better, such as a 1000 w. with a surge capacity, for faster recycling. But then I noted that you initially used two 300 w. Samlex inverters, but the bat voltage dropped too low. So I guess using a larger inverter would do the same?

 

Do you have any idea why the AIMS 300 wouldn?t work? Looking at the specs, there shouldn?t be much difference. Is there any way to determine, before purchase, whether one brand of pure sine wave inverter would work better than another?

 

Thanks!

[savagesax]

Way to go, I built mine too! so easy! I picked up an enclosed rolling cart with big wheels at Home Depot for $30 so everything is on wheels. The weight doesn't matter! Now you can also change batteries on the job! I do have a background in electronics but still the wiring is pretty simple. Make sure you use car battery size cables running from the inverter to the the battery. An inverter with a built in fan is also nice to keep things cool. I use this whenever the power goes off, such as quakes.

[savagesax]

I also rent mine out! Paid for many times over. It's about 7 or 8 years old, same batteries. I use a slow trickle charger.

[marknagel]

R. Eric Summerfield,

 

Not sure why the AIMS didn't work. A couple posters on Dpreview said they had problems with the AIMS too.

 

m

[conraderb]

this is so cool.

 

Mark, do you happen to have the links to the exact inverter and battery you are using? I see it is a werker, but there are so many werker options. I am dumber than a phonebook when it comes to electronics, so I would want to see exactly what inverted/battery you used so I can order the same thing.