Battery Amp Hour Rating – This rating is based on the size of the battery that you purchase. Higher amp hours run . Our advice is to buy the largest battery that you can afford or carry. Portable or compact units are often rated in Watt Hours (Wh) or sometimes milliampere-hours (mAh). All of these numbers represent the capacity of the battery and can be easily converter to Amp Hours. Set this slider to your battery’s amp hour rating. Watt Hours / 12 = Amp Hours Milliampere-hours / 1000 = Amp Hours.

Battery Usage % – To maintain the long term life of your battery it is recommended to not drain the battery below 50% of it’s capacity. Set this slider to determine your usage percentage.

Wattage Draw – This is the amount of watts that are being used. To determine this number, take the wattage of each bulb that you are using and add them up.

Let There Be Light!!

Over the years, ProPanels has spent a lot of time trying to solve the problem of lighting a portable art booth off of a battery. Various configurations of 12-volt batteries, automotive, marine and RV light fixtures and bulbs were tested to no avail. In recent years though, we have been introduced to some really exciting LED technology that is finally energy efficient enough to make running it off of a battery possible. To test it, we took an old 12-volt battery and charger that we had laying around and a power inverter and gave it a try. The results were so promising that we decided to dig further.

Keep in mind that while we do sell an excellent LED lighting set-up, we don’t sell the components needed to run it off of a battery – this is just information to help you acquire the necessary hardware. We have tried to make this as clear as possible. If you have further questions after reading, please contact markburris@propanels.com.

Here is what we came up with:

Battery:
We started with a regular acid flooded deep cycle marine battery that we bought at Sam’s Club. This battery is rated at 125 amp hours. The number of amp hours is indicative of the capacity of the battery. The higher the amp hour rating the longer the battery will last. There are other gel or glass mat type batteries that would be better suited for extensive traveling. These types of batteries are sealed, maintenance free and are typically more expensive. Choose the battery that best suits your needs. Our best advice is buy as large of capacity battery that you can afford or carry!

Charger:
Next is a state of the art automatic battery charger. We found some affordable units on Amazon.com for around $60. The type we bought is automatic which means it won’t over charge your battery. It has a digital readout so you can see when the battery is fully charged and the amount of voltage being put into the battery. Also it is designed to handle all types and sizes of batteries. We bought the Schumacher SSC-1500A-CA Ship ‘N’ Shore 15 Amp SpeedCharge Charger with Battery Clamps.

Inverter:
When it comes to inverters, bigger is not always better. We settled on 200-watts. This is big enough to run all the lights, but not so big that it draws more amps than needed. We found that using a larger (400-watt) inverter drains the battery faster than the 200-watt. We bought ours from a local electronics store for around $20.

Other Items:
You will also need a cigarette lighter to battery clip adapter and a good multi-meter. The battery clip adapter converts the cigarette lighter plug on the inverter to battery clips and the multi-meter will help you measure various aspects of set-up.

The Set up:
The battery adapter clips to the terminals on the battery. The inverter then plugs into the adapter and the cords from each of the lights are plugged into the inverter. Our inverter only had 2 outlets, so we also used an extension cord to allow us to plug in 3 cords.

The Test:
As mentioned earlier, the amp hour rating measures the battery’s capacity. To determine the amp hours needed the formula is (amp hours = amps used x hours). Our multi-meter helped us determine that our system is using just shy of 9 amps. So based on the formula we should be able to get about 14 hours out of our battery. To help maintain the life of our battery and to keep the recharge time quicker, we chose to run our test for 8 hours.

Our 8 hours test ran over a 6-day period. We always started with a fully charged battery and ran 3 sets of track lighting each with 2-14watt Par30 LED bulbs for a total of 6 bulbs.

On the first 2 days, we connected the lights to a fully charged battery and monitored the voltage every hour. The voltage ranged from 13.7 volts in the beginning to 12.3 8 hours later. At the end of the 8 hours, we connected our automatic charger to the battery and allowed it to fully recharge, usually overnight. The system ran perfectly for these 8-hour test periods.

On the third day we wanted to simulate traveling to an art show. The battery was fully charged on Friday morning, but we waited until Monday morning (72 hours later) to plug the lights back in. Again, the results were the same, 8-hours with no problems.

Conclusion:
We couldn’t ask for better results from this system; it worked flawlessly in our test. It produced the same great light output with the battery as running it on a regular electrical circuit. We have seen other 12-volt systems, but none with high light output (over 5400 lumens) while maintaining an even light distribution and lasting 8 hours between charges. Also, being able to use regular electrical current when available and switching to battery power as needed is a huge added benefit.

As always, your results may vary and anytime you are dealing with batteries and electricity safety is paramount. Please be careful. We are still working on these tests and if any new insight is developed we will definitely share that information too. Also if you have any information regarding your experiences with battery powered lighting please forward any relative information to markburris@propanels.com

Lastly, here is a great link with a lot of great information regarding batteries and charging. Battery Basics

Pros:
Great light output and light quality
Save money on electrical booth fees
One system works on both 12-volts and 120-volts

Cons:
Batteries are heavy to carry
System needs to be recharged every night after a show
Requires more effort to tend to battery