Hi all, I'm hoping somebody can help me as a novice. I am a photographer with a home studio and we have been having a lot of power cuts lately. I was thinking of getting some sort of generator that I could use in an emergency if I have clients in and we have a power cut but as it would be noisy/smelly somebody suggested some sort of battery pack.

I need to power a 500w strobe light and ideally two 200w lights but could get away with just the 500w. Would a UPS be something I should be looking at? I don't actually want to have it plugged in all the time, I just want to have it charged up in the house so that if we do have a power outage I can take it down to the studio to use for an hour or two. Is there such a thing as a battery pack that isn't a ups or could I use a ups system without having it plugged into my strobes all the time?

Also would I need to look at a 1000w ups system? my strobes all fire at the same time but I wouldn't be using the full 1000w constantly, they are just flashes with several seconds/minutes in between.

Thank you for any help!

 

I assume they are 120V lamps. If so a UPS is definitely the better choice as it already contains an inverter to change the DC voltage from the battery into AC. If they are strobes they shouldn't be pulling that much wattage all the time, a UPS of lower rating may suffice if not too far underrated. That being said, UPSs are likely usually expecting a continuous load and not a transient load. I am not sure if the transient power demand would have any sort of detrimental effect on the UPS. Can you say for sure if the 500w and 200w rating are actual power usage ratings or are they 500w and 200w equivalent light output? Are they LEDs or some sort of incandescent/gas bulb?

 

Most UPSs are designed to give you enough time to do an orderly computer shutdown. There are larger industrial UPS units but they do get pricey. Not knowing how long your outages are... Short blips are easily managed by UPS. Longer outages usually require a separate power source such as a generator which for a bit more cost can have automatic start and switch over capabilities.

 

I assume they are 120V lamps. If so a UPS is definitely the better choice as it already contains an inverter to change the DC voltage from the battery into AC. If they are strobes they shouldn't be pulling that much wattage all the time, a UPS of lower rating may suffice if not too far underrated. That being said, UPSs are likely usually expecting a continuous load and not a transient load. I am not sure if the transient power demand would have any sort of detrimental effect on the UPS. Can you say for sure if the 500w and 200w rating are actual power usage ratings or are they 500w and 200w equivalent light output? Are they LEDs or some sort of incandescent/gas bulb?

Thank you for your reply. The strobes are not led, they have a flash tube which has some sort of filament inside. Looking at the instruction manual for operating voltage is says '230V AC 50Hz or 115V AC 60Hz' and it just says max power 500w. Sync voltage 5V DC. This doesn't mean much to me as I know nothing about electircs!

 

Hmmm. SamR makes a great point. May be able to find a small UPS intended for rack servers that accepts external battery packs. You can extend the runtime for hours like that at a cost. But it's not likely to be cheap. We spent just over $8,000 for a UPS with battery pack from APC and it gives us just under an hour and a half of run time with a load of around 425W.

 

Read through this thread. The TS wanted to power a tennis ball machine in a remote area. There's some good discussion about UPSes and portable power stations.

https://forum.allaboutcircuits.com/...-battery-that-would-power-this-machine.181112

 

A UPS can be used for that, However as someone who has used studio flashers, and lighting in the field I would suggest first looking towards what kind of connections your equipment has, this can save a lot of money or trouble, and it will give you a lot more playroom.
First, a ups would actually be great and possible the best choice if you are a decent sized company, need as little manual work in it, and just need to power all your devices on a power outage. shower you need to look towards voltage and amperage or wattage it can output and the total power it can store. since you said you'll only use it for some small things, the maximum output wattage is the most important, you will want to have some playroom in the wattage to prevent heating up the ups.
However, many studio lights, or studio flashers also have a dc connection or a dc to ac adapter for the model. this allows you to use normal battery of your desired kind(for example a 12v car battery, lithium cells, a generator, or capacitors) if you can live with manually charging them and manually connecting them to the flashers and lights after a power outage(manually switching) this can save you a lot of money, and it can be helpful might you ever have shoots in the field. dc to ac converters can also be gotten really cheap, and with them you can easily use the normal power plugs to run the devices from battery, again this can save money and gives you more flexibility.
but a ups is certainly a valid option if you have the resources for one. that way you might be able to work on and not notice there is a power outage. however watch the wattage of the ac output to make sure it can handle the setup, and make sure it is a ups more like what you use in a small datacenter or for a server, so one that can run for long amounts of time, and has enough WH of energy to run for as long as you desire. so take the voltage of the battery* the amperehours. divide it by 100 and multiply with the efficiency of the dc to ac converter take a few % extra of the answer since in reality it will not be that efficient. then divide the answer by the wattage you use per hour(1000 in this case) and the answer would be how long a power outage can last before the backup runs out.

 

A UPS can be used for that, However as someone who has used studio flashers, and lighting in the field I would suggest first looking towards what kind of connections your equipment has, this can save a lot of money or trouble, and it will give you a lot more playroom.
First, a ups would actually be great and possible the best choice if you are a decent sized company, need as little manual work in it, and just need to power all your devices on a power outage. shower you need to look towards voltage and amperage or wattage it can output and the total power it can store. since you said you'll only use it for some small things, the maximum output wattage is the most important, you will want to have some playroom in the wattage to prevent heating up the ups.
However, many studio lights, or studio flashers also have a dc connection or a dc to ac adapter for the model. this allows you to use normal battery of your desired kind(for example a 12v car battery, lithium cells, a generator, or capacitors) if you can live with manually charging them and manually connecting them to the flashers and lights after a power outage(manually switching) this can save you a lot of money, and it can be helpful might you ever have shoots in the field. dc to ac converters can also be gotten really cheap, and with them you can easily use the normal power plugs to run the devices from battery, again this can save money and gives you more flexibility.
but a ups is certainly a valid option if you have the resources for one. that way you might be able to work on and not notice there is a power outage. however watch the wattage of the ac output to make sure it can handle the setup, and make sure it is a ups more like what you use in a small datacenter or for a server, so one that can run for long amounts of time, and has enough WH of energy to run for as long as you desire. so take the voltage of the battery* the amperehours. divide it by 100 and multiply with the efficiency of the dc to ac converter take a few % extra of the answer since in reality it will not be that efficient. then divide the answer by the wattage you use per hour(1000 in this case) and the answer would be how long a power outage can last before the backup runs out.

Thank you for that, there is a 'battery input' socket (U in this pic) as you used to be able to buy a travelpac battery for the strobe but since the company, bowens, went out of business there doesn't seem to be any replacement. Would I just need a compatible lead for this socket to plug into say a car battery?

 

Thank you for that, there is a 'battery input' socket (U in this pic) as you used to be able to buy a travelpac battery for the strobe but since the company, bowens, went out of business there doesn't seem to be any replacement. Would I just need a compatible lead for this socket to plug into say a car battery?

View attachment 249544

I found someone online saying the battery itself was 12v. however the battery pack has a lot of cirquitry on top of it, so it might be the flasher itself does not support 12v dc, or requires a 12v adc, a authenticy check, multiple voltages, or anything. I don't think it will be easy or very safe with such a connector unless there is a propper datasheet. the flashers I know accept direct dc power from 12v battery and have only 2 connections(1jack). it is still possible, but there is a chance it will require a lot of additional hardware like that, so the 12v inverter(converts 12v dc to 230v or 120v ac), or the ups might be a better option in this case. with those 2 methods you can use the original plug.

 

Thank you for your suggestions, would something like this work if I just wanted to run my main strobe? just something I found on Amazon, it says 700w and my main strobe is 500w

 

When a UPS loses commercial power it alarms, audibly. Some can't be silenced permanently. UPSs are really not designed for what you want to do and I am skeptical it will work well for you.

If you do want to try, you must be sure you get an online UPS. The circuitry that converts battery to AC in a UPS is under a lot of stress and cheaper UPSs only use it when commercial power is lost. It is very likely that if you use it regularly it will fail, possibly quite dramatically. An online UPS is constantly generating the AC it outputs from commercial power and switches the same circuitry to battery when commercial power is unavailable.

This will cost more.

All in all, I think you'd probably be better off with some deep cycle marine batteries, an inverter, and a battery charger/maintainer. Even thought this sounds like an a la carte UPS, the components are very different to the highly optimized and value engineered UPS parts.

 

Ah right, it seems a lot more complicated than I thought it would be! I was hoping I could just get some sort of rechargeable battery to plug my lights into but not to worry. Thank you all for your help

 

Ah right, it seems a lot more complicated than I thought it would be! I was hoping I could just get some sort of rechargeable battery to plug my lights into but not to worry. Thank you all for your help

You might want to look into modern battery powered monolights. They do exist and offer good power. They can run from AC or from internal battery and are quite portable if you can use that.

 

Personally if you consider a UPS consider the output waveform type and if for example a MSW (Modified Sine Wave) output is suitable for your needs or do you need a TSW (True Sine Wave) output with the latter being more costly. Next when considering a UPS you need to know not only how much power it can supply but for how long? A power loss of an hour won't fare well with a UPS which will support you for 15 min. I also agree as to use of deep discharge batteries.

While many older generators can be loud and noisy many of today's run very quiet. Depending on what you want to spend there are nice units with fully automatic transfer systems which can be ideal for a business. If power outages are frequent you really may want to consider something along those lines. They can be powered with gasoline, diesel, natural gas and or LPG (Liquid Propane Gas). We use a natural gas powered auto transfer 16 KW unit which powers everything including AC in the summer. During winters I hate dark and cold. My UPS units only need to backup computers, phones and other items for less than 60 seconds on power outage.

So it all comes down to what works best for you and budgetary constraints. With a home studio I would lean towards whole home support.

Ron

 

Thank you for your suggestions, would something like this work if I just wanted to run my main strobe? just something I found on Amazon, it says 700w and my main strobe is 500w View attachment 249579

The documentation contains a graph showing how long it could power a certain wattage. this one can according to that graph power your light for around 3 to 4 minutes, as well as that this device uses basic lithium cells of a similar capacity as a small power bank, so I would not recommend it for this for your case, a server ups could do such a thing but new they are very expensive. however the other way I mentioned using a inverter(yaakov said something similar) is really a lot cheaper, more reliable, more durable/maintainable, etc. you only need some batteys probably 12v, however you can also get lithium cells, however that requires a more exotic inverter. such batterys you can get anywhere and you probably already have them. a new 3000w inverter costs around 50$ however if you are in the USA you can probably get them a lot cheaper at a random local store. do however make sure it outputs your ac voltage, manny have a switch for it, but just make sure it supports it, and that if there is a switch, that it is set properly.

the only real trouble you get extra is that you need to manually charge them, and when the power drops you need to manually enable them. but that all can be fixed quite simply using a basic arduino(uno for safety and voltage peak handling) and some relays. manny modern chargers for example have lights on them indicating if the battery is full, you can read this signal using a ldr, or by connecting a signal probe(cable with voltage dividers of high resistance) to the led leg. otherwise you can read the battery voltage directly, however this might require some more testing. since most chargers automatically stop charging you can also start the charging and keep it going until a certain amount of time has passed. like that the charging is automated and will start when the arduino starts(so when the power comes back on), to automatically switch between wall power and inverter power you can use relays again, 1 relay in front of one of the terminals of the inverter then control the mosfet/transistor that drives the current through the relay coil(T1) with another transistor by connecting a very high resistance resistor to Plus of the battery, then when the arduino uno is on(so when there is power) it enables the transistor T2 to ground causing the gate of T1 connected in front of T2 to stay low and the inverter to stay of.
in a similar way you can add a extra double connection(ac) relay to the output of the inverter and the ac power line this makes sure that only one of the 2 power sources can be used at one time, you can also use 4 normal relays for this as long as they can handle the amperage and voltage while the inverter and ac should not be on on the same time, some defect might cause it, and some inverters might lack proper protection so this is more of a safety measure, especially if both for some failure are on at the same time but are out of phase.
that way you have all the benefits of a ups, but a lot cheaper and more durable than a average psu. but if you aren't to much into the electronics it is best to manually charge it and manually enable it, since you do not need it to protect something but just to have power on a outage.
I had a drawing of the cirquit but it got corrupted because of some problems. my drawing tablet also got fried by something so remaking it would take to long. but if you are to build something to automate that I guess it would be rather simple with a aruino, 5v charger, battery pack charger, battery pack, 7(or 8) relays, and some transistors/fets and resistors.

 

I don't actually want to have it plugged in all the time, I just want to have it charged up in the house so that if we do have a power outage I can take it down to the studio to use for an hour or two.

The UPS' I am familiar with (the small computer home office type) use Sealed Lead Acid batteries (SLA's). They need to be kept at a float voltage at all times so that when a failure occurs they're ready to go and just take over the job instantaneously. If you plug one in and charge it up, then unplug it and set it on a shelf you will be grossly dissatisfied when you try to use it. SLA's need to be charged regularly. I keep a few SLA's laying around for random projects. Periodically I have to remember to charge them, even if they haven't been used.

When an SLA sits uncharged for long times they develop scale on their plates and don't allow them to deliver their full charge. Their voltage will likely read full charge but they will not be able to do the job intended. A few years ago I gave Christmas gifts of those battery boosters you keep in the trunk for when you have a dead battery in your car. I told my friends they need to charge them every 3 to 4 months otherwise they will not work when they want them to. Being that they are not electronically minded they didn't charge them but just periodically pressed the test light and it would say the battery had full voltage. However, when they needed to jump start their cars the thing failed because the battery had developed that scale (called "Sulfation"). I've even forgotten to charge SLA's and when I wanted to use them - they were no-go's.

Bottom line, you can't charge a UPS and then park it on the shelf for the next time you need it. It should be plugged in at all times. One idea I've toyed with but not pursued is to use the UPS with an external car battery. A large 12V car battery (a wet cell, not SLA). In theory it should provide longer run times. But again it must be maintained. But then comes a question I have no answer for - "Can the UPS charge such a large battery without being damaged?" So - will your proposal work? Maybe. If you make modifications such as adding external batteries, will your UPS survive the extra charging load? I don't know, but suspect quite possibly not.