Art Fair Insiders

Call for Artists, Making Money at Juried Art Fairs, Craft Shows and Festivals

I got lots of great ideas from this site on running my booth lights from a Deep Cycle Marine battery.  Here's the setup that I pulled together.


From Amazon

Charger - Schumacher SC-10030A SpeedCharge Automatic Charger and Maintainer 5 yr warranty

Inverter - Wagan 1000 Watt Continuous Power Inverter Model 2294 1yr warranty


From Walmart

Battery - Everstart MAXX-29.   Also a battery box.  18month warranty


From Home Depot

EcoSmart 18-watt LED Flood E*  Model # ECS 30 V2 WW FL 120 Internet # 202670523

Store SKU #406027 Equivalent to 90 watt flood  3000 degrees Kelvin 5 year warranty


With this setup I am running 6 lamps in black swing arms from Flourish.  I tested this setup and am able run in excess of 10 hrs, actually got to 12 hrs before I shut the system down.

The inverter and charger are much larger than you might need but I wanted something that was robust.  Charge time runs 5-8 hours after I have run the battery to the 50% point indicator on the charger.  The inverter is much more than needed but I wanted to run it at less than rated capacity to help keep heat down.  I put the battery under my ProPanel work table and there isn't a heat issue.

After the first two shows I took a piece of 1x12 pine board, added casters/rope pull and strap the battery to it so that I can pull it in and out of the show for charging in the evening.  Left room to put my cooler on it.

It is HEAVY, something like 70# or so and keep that in mind as you are taking it into and out of your vehicle for charging back at the hotel or wherever. 


Views: 21564

Reply to This

Replies to This Discussion

I'll have to get back to you on that one. The 10.5 volt cut-off for inverters is keyed to the discharge curve of the lead-acid battery. Once the specific gravity of the cell hits a redox potential of 1.75v per cell instead of the 2.23V of the fully charged cell, it's a sudden and rapid drop of capacity after that. The 10.5 volt limit is supposed to be the magic mark. The internet has a lot of confusing and contradictory information. I've seen the 50% figure cited before, but nothing that gives an explanation of why or what determines the 50% point. I have that information in one of my old engineering textbooks, but heavens only know where it's at it as that was 35 years ago. Some things about chemistry just don't change ;-)

For flooded cells I'm certain that you start to see a lot of sulfation and flakes of lead sulfate coming off the plates that might be part of the redox chemistry physical reactions
Oscar when you hear the signal that is the point at which the inverter does not work properly anymore that is different then the battery capacity

So how you figure when the battery is 50% capacity.

If you had a digital readout on your inverter, you could get % charge or voltage. But voltage isn't everything. Age of the battery (older is bad), outdoor temperature (hot and very cold are bad) and efficiency of your inverter (inefficient inverters will drain your battery faster) all lay a factor. As your battery ages, it doesn't charge like a new one and you don't get as much power from it compared to a new one.

Find the links I poster to the battery calculator pages for more info. Just remember, it isn't so much voltage, but capacity of the battery. Yes capacity and voltage have a relationship, but not 1:1. Robert, you want to explain in plain English?

Voltage can be a close approximation of the percentage of the remaining charge, but it doesn't say what the remaining capacity is. 13.4 to 13.8 is full charge depending on the temperature. From there it goes downhill steadily in a fairly straight line, all things being good. When it hits 10.5 the chemical reaction is about exhausted and the voltage suddenly goes from a bunny ski slope to a sheer drop off. Go past the drop off and you've screwed the battery. 

The percentage of remaining charge is a good thing to know, but that still doesn't tell you how many watt/hours or amp/hours are left. You could have 70% of charge remaining, but if all that amounts to is another 20 A/H then you're screwed if you need another 80 A/H.

I'm not up on the latest microprocessor driven inverters that do the computations of a lunar lander to tell you how much time you have left, but I would imagine those are out there and the folks who make them are willing to take your money. Monitor your current and run time to see what % you've dropped, and you should be able to estimate how much time you have left.

I know what the supposed capacity of my batteries are, I know what the current drain is, and between those two I can estimate to within a reasonable degree what my battery life is going to be. What confounds all this is that the amp/hour ratings are based on a 20 hour span. No problem; that 105 A/H battery is good for 5 amps at 20 hours rounded off. Now if you look at the reserve ratings that are based on a 25 amp drain, that same battery will hold up for 180 minutes. That's only 75 A/H. Yep, it's just like horsepower, it takes more hp to go faster. Double the speed, and it takes four times the horsepower. Drain the battery faster, and it takes more out of the battery to deliver that.

Solution; get more battery than you think you need, then put together the package before a show and run it to see how long it lasts. If it doesn't last as long, then take the battery back while you can and exchange it for a bigger one or use a two battery pack to get a higher capacity. I've thought more than once about taking some old surplus panel meters and rigging up a current meter and a voltmeter that reads from 10 to 14 volts. If I could find the voltage/charge graph, it would be easy enough to make a new meter face to include percent of charge. Mein Gott in Himmel! That sounds too much like my previous life =8-0

And..... that would be why you use the battery calculator.........

Using an inverter? -

Take the results from that calculation and enter it into the following calculator


Battery calculator


Anyone try to run MR16 led bulbs in regular line voltage track lights using a battery source instead of line voltage?  I had a show neighbor recently who did this. I just can't remember if there were any tricks to it like fuses required, etc.  There are some very bright 6 watt bulbs being made now and I'm ready to invest in lithium ion and set something up that will last 2-3 days.

I did it for a while. The problem I ran into is that the current drain was much greater with 12V lights running direct off a battery. There wasn't any really battery saving. Even though the 12V running to the fixtures was heavy duty (12-ga) it still heated up something fierce. 

I still have about 15-18 MR16 fixtures with the transformers removed that fit 110V track. If you want to try it, contact me off-list. 

I need to light up my tent... and I understand not that much about currents ect..... I tried... got an inverter...> my trusty 5 in one car battery... and it lasted mmm 1.5 hours..? Im thinking I need to upgrade? I have... > Progress Lighting - P9215-28 - Alpha Trak Kits lighting which has a plug and four lights on it..
and I could add another lighted track.. with 4 lights on it…. but I guess I should deal with one track of 4 at a time..
My question is… how do i keep them lit for several hours… ? in 2017? i'm using 4- led bulbs 12w/120v 60hz, 3ut1 Im pretty sure I used the wrong inverter the first time out…(too weak) and I used a car battery charger (i figured this out without google) … 1 hour… THE inverter spoke to me… and seemed to be using a lot of energy to change from the battery to the plugged in unit! ...(whispering,, sounded like something from a horror movie when its energy was dying out!, it speaks!) anyways.... this is what is suggested... I need simple answers... (pictures help) .. and the WHY's so I can understand as well . I can and want to learn, I 'will' learn but it does not come naturally, this stuff so dumb it down, pls. .... I cannot afford to waste money... I haven't the tools to weld... and I want to use my lighting again for things other than the tent when Im done with it..and although Ive worked in a machine shop... this wasnt one of the skill sets Ive learned! Help appreciated... Janice

Search for a company that is a good resource for batteries and chargers. I have gotten good information from Power Stream in Utah for batteries and especially chargers and 1000 for lights. I chose to make my system 12 volt so no converter is required. That may be more than you want to deal with as I had to retrofit my track lights to accept 12 volt bulbs without using fixtures that have their own transformers to work with 12 volt bulbs. I have three 100 amp hour batteries which is a $900 investment and I can run 18 7.5 watt lights for a three day show. Each battery takes time to recharge. Batteries need to be kept fully charged and maintained.

Thats kind of you to reply Paul... I need something simpler... and I do wish to be able to use the lighting in other ways.... hopefully someone will respond with answers to both my question ie.. what do i need? in regards to batteries ect.  and considering my limited capabilities. 


15% Off All Orders! We are offering 15% off every order now through May 31st, with our best wishes for a swift economic recovery for all!

Fiber artists -- use this resource to find new buyers:  Advertise with Reach over 60,000 fiber arts lovers.

Our 50 Best Art Fairs

Look Inside the 2018 Art Fair Survey:
Who Won and Why

Join the MasterMinds Group for personalized coaching on your Internet Lifestyle Business! 

60 Page Report - Best US Art Fairs

Click Here to
Learn More


  • Add Photos
  • View All

© 2020   Created by Connie Mettler.   Powered by

Badges  |  Report an Issue  |  Terms of Service