Mains or Battery 12 Volts

Many people assume you always need mains power and nothing can be further from the truth as many things run from 12 volts as this is the standard car battery voltage and an entire industry has arisen around 12 volt systems as they are used in caravans and motorhomes and to a degree, camping. Many mains powered systems also run of less than 12 volts and anything electronic runs off 5 volts which means your mains powered item has a step down transformer to get it from mains 240 volts AC to 5 volts DC so can you run these things from 12 volts? In actual fact yes and transforming from 12 volts to 5 volts DC is easier then mains AC to 5 volts DC.

If you want alternative power sources you generally need battery storage and this is usually 12 volt batteries as this is the standard, if you build your own battery pack from lead acid batteries you have no risk of thermal runaway which you get with lithium batteries so they are safer in the home. Many security lights now run off 12 volts and others run off 30 volts so a large battery pack can run security lights and you can get cheap digital battery chargers to recharge your battery pack, or you can have multiple battery packs for different purposes.
Recharging is not tied to mains charging as new solar panel technologies are filtering through and these are much better and more efficient than older panels and despite the rhetoric about capacitor storage the only way to guarantee power storage currently, is battery storage, and the most popular battery systems are vehicle batteries. You can now buy small wind turbines and these are very effective and while they produce less peak power than solar they can produce it 24 hours a day and not be tied to sun or daylight, water turbines are another way to produce power and there are some elaborate systems already out there. In reality most people can make a compact wind turbine or water turbine using basic DIY skills, how long have water wheels been around? Recorded examples go back to the 1600’s so nothing new.

Many things in or around the home can be converted to run off 12 volts and many current LED light fixtures are run through a mains powered LED driver which drives a series of connected LED strips, so why not put some 12 volt LED strip in and connect these to 12 volt wiring and run a little plug through the side of the fitting and you have a mains powered light with additional 12 volt back up and if the power goes out you connect a 12 volt battery to it and you have light, admittedly not as bright as mains powered light, but you have light. If you apply this to important lights such as the main living room, kitchen, and hall ways you will have sufficient light to see by and move around your house and if you have 2 or more battery packs you can install 12 volt lighting in important areas such as sheds or workshops or even log stores so you can see sufficiently to get items from your shed, or collect logs of you have a log burner. If you have outside security lights run from 12 volts and you have a power outage and thieves strike you will light them up and surprise them and usually they will run away and not bother you again in a power outage.
Similarly, many home CCTV systems run from 12 volts and wireless security cameras almost exclusively run from 12 volts and many can run from 9 – 12 volts and while your NVR (network video recorder) will not work you have other options as many systems have an optional wireless monitor which is rechargeable and receives your CCTV pictures live. Many have a run time of several hours between recharges and this means you can monitor your cameras and as many recharge from 12v they can be recharged and this is another benefit, you can recharge so many things ranging from power banks, emergency lights, laptops and mobile phones to name a few.

If you have a small engine and a vehicle alternator you can recharge a battery pack as most alternators are machine regulated which means the alternator measures the amount of current which is required and supplies it, you can also fit a wire and get the batteries to dictate the alternator charge which is more accurate, or your car can be pressed into service if necessary.

What happens if your lights go out and you connect your battery to converted lights and the mains power comes back on? Your light suddenly gets brighter as both your 12 volt and mains voltage light it up and you easily tell mains power is back on and you can disconnect your battery. You can eliminate batteries around your home with a 12 volt system in your home and all you do is turn your 12 volt batteries on and hey presto instant light and whatever else you have connected to the 12v system, and all connected to a single switch.
You can get a range of appliances from the leisure industry and while a 12 volt kettle is fairly normal you can go as far as 12 volt ovens and even sandwich toasters and your 12 volt systems can make drinks and food and realistically, how far do you want to go.

To all intents and purposes 12volts can do everything mains voltage can and it just does it differently and while you may need mains voltage your 12 volt system can also supply it as if you have enough battery capacity you can connect some tiny to very large inverters to them and supply a little or a lot of mains power or you can mix and match and use varying proportions of both.

Charging and maintaining a system is not a chore these days as battery monitoring and charging systems can be programmed to accept charge from alternative energy sources such as solar or wind and while both have benefits they also have liabilities and this is where a good system takes over as much of this technology comes from the off roading and overlanding industry. Your solar may work during sunny days but not at night so you have to get enough charge during the day to last all night, likewise wind turbines may be small and lack the peak output of a solar panel at full output but they win by producing power day and night and this is their great advantage and the reason some companies employ turbines with solar panels, or solar panels with a wind turbine. This is where the electronics take over and modern battery monitoring systems can be programmed to kick in when required, let me explain; if you have a dull day which is also still none of your systems really produce anything and if you programme your charger to kick in at 60% battery charge and the battery charge drops to 60% the mains charger will kick in and use mains power to charge your battery. Never stick to solar as an alternative to charge your batteries as wind or water power have their place and realistically they are free, you do have to pay to build the generator but these are easily and cheaply done so let’s give it some context.

You look for an alternative to mains power so you can spend more money if you guy a generator as you have to buy fuel for them and maintain them periodically; without fuel they do not run and by comparison they are an expensive source of electricity. Small solar set ups are costly to buy and while they get better and cheaper you only have the initial outlay of the solar panels and the controller as well as the storage batteries, similarly you will add the cost of an inverter if you need mains power and your savings come in the longer term as you don’t need to buy petrol, diesel, or gas to run them and they don’t need servicing other than cleaning. Wind turbines and water turbines are basically the same in principal and operation and unlike solar they don’t rely on bright daylight as in winter in the UK we get high water levels and much more wind and they work at their most efficient and while they are not on the same peak power levels as solar, they work day and night and produce a more consistent power for much longer. In reality they are more proportional for the UK as in winter we need more power as the short daylight hours means more lights, cold days means more heat and we stay indoors for longer and use equipment such as TV’s, satellite or cable services or computers and they are need power for their use as mains units or for recharging.

This is the major issue, with mains power you are more likely to get power outages in winter and this means more requirements for alternatives and generators have petrol storage issues with E10 petrol and it assumes you have petrol or diesel available when you need it; if your local garage is affected by power outages also, you either have to travel further and longer for fuel meaning you are without power for longer and this can be an issue for elderly, disabled, or other vulnerable people. If you use your brains and buy wisely you can get a mix of alternative power sources and there are no rules which was you have to have solar or you have to have wind as modern charge controllers support both types and you can have solar into one input port and wind from a turbine into another port and the common denominator are your 12 volt batteries and if necessary you can upgrade as time and money become available. If you have a shed or workshop with a workbench at one end and you only really use hand tools and possibly small battery tools such as a cordless drill you can fit a couple of 12 volt lights over your bench and use them to light your work area and you are saving money on mains electric and using what nature provided, and you stored.

If you do this with many things or applications you can replace many things and use 12 volts instead of mains power and most CCTV cameras are 12 volts so put another battery pack in a position to power another one or more CCTV cameras if you have the hand held rechargeable receiver you still have some CCTV in the event of a power outage and while you may have no NVR (network video recorder) you can still watch your battery powered cameras in real time. All my CCTV security cameras are on battery back up and they are fed from multiple battery packs which are freely charges from alternative sources and the NVR is also powered by 12 volts and this means we have it backing up all our cameras. Many of my cameras are PZT or pan, zoom, tilt which means they can be panned, zoomed, it tilted around and these functions still work and some are auto tracking which means if they detect something they follow and track it and automatically take images every 10 seconds, and these still work and the monitor is a large TV running on mains voltage and 12 volts.

You may switch some of your security or outdoor lights to 12 volts and they really show in a power outage when there is no light and they really surprise intruders when they are expecting no security lights and suddenly get lit up.

You can split such systems with decent battery back up or simply run them solely off 12 volt batteries and get the intelligent chargers or charging modules so if your battery capacity drops to 60% (mine are set at this) the mains recharges the batteries to 90% before it cuts out.

Thank you Assassin for another great article.