In the event of a blackout, you may need to keep powering important systems (computers or medical equipment) that need to stay on at all costs. This guide is about a modular UPS. You can expand it with an electric generator, solar, wind, etc., according to your preferences.
Most uninterruptible power supplies sold for desktop computers have a small inverter that operates when the power fails and returns to "normal" mode under normal conditions. This produces an alternating current with a continuous inverter and uses one or more systems to charge the deep-cycle battery faster than the time it takes to discharge it. This makes the design simpler, and also allows for more than one type of direct current to charge the batteries. This will be an online UPS.
Steps
Step 1. Read all warnings before proceeding
Do it for your safety.
Step 2. Choose a charger that can provide the current needed to charge the battery and cope with the inverter charge
It will be a fairly strong inverter.
- Buy a power converter that is designed to work with larger RVs if you plan on building a large system.
- Check out solar power sources to use as a whole house charger and inverters for a very large system.
- If an RV or converter has a built-in inverter, make sure it is isolated from the current input.
- Make sure the charger can handle the batteries you want to buy.
Step 3. Choose only deep-cycle batteries
Do not use a car or truck battery or a marine battery. If you are going to use only a gel battery or a maintenance free one, it will be fine. For systems consisting of multiple deep-cycle batteries, select are wet cells or AGM.
- Make sure the batteries are vented for hydrogen gas leaks.
- If you buy wet cells, make sure the charger supports an equalized charge.
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Lead and acid batteries are sold in 6 and 12 volts. You will have to connect them in series to increase the voltage, or in parallel to increase the amperage and the hours of autonomy.
- 12 volts = 2x6V batteries connected in series.
- 24 volts = 4x6V or 2x12V batteries in series.
- When you connect in series-parallel, connect a pair of batteries in parallel and then the same pair in series, not chains of batteries in parallel.
- Do not mix different types of batteries. New batteries along with old ones tend to wear out faster.
- When you have large series-parallel patterns, it is good to replace the batteries every year.
- Cycle batteries last longer, while deep cycle batteries last shorter.
- A new, fully charged 12 volt battery has a voltage of 12.6 at rest (each cell is 2.1 volt).
- A new 6 volt charged battery has a voltage of 6.3 at rest.
- When a 12 charger is active, the voltage will be higher. A float charge for a 12 volt system is 13.5-13.8 volts; an active charge requires 14.1 volts. It could also go up to 16 volts in charge, depending on the charger. After a full charge, if the battery does not go into float charge, the quiescent voltage will gradually return to the full charge voltage.
- A discharged 12 volt battery has a voltage of 11.6 at rest. A discharged 6 volt battery has a voltage of 5.8. The voltage can temporarily drop below these levels while feeding a large charge, but should return to normal after an hour of rest. Discharging the battery below 1.93 volts per cell at rest will permanently damage the battery.
- You can measure battery charge with the voltmeter, but many batteries often have an "empty charge" that wears out quickly when in use. You will have to test them "live" for several hours and check their efficiency.
- A 12 volt UPS cannot fully charge a discharged 12 volt battery, but still gives a good charge if the output voltage is correct (13.5-13.8 volts for a 12 volt system). Check the water levels in the cells often and fill them when needed with distilled water.
Step 4. Choose an inverter
- Choose one that is consistent enough to hold more current than needed.
- A peak current sufficient to handle the starting loads of the motor, which can be 3-7 times higher than the running wattage.
- Inverters are available based on input voltage, 12, 24, 36, 48, 96 volts and other common voltages. The higher the voltage, the better, especially for larger systems - 12 volts is the most common system, which obviously cannot be considered if you have 2400 wattage output (too much current to handle).
- Some of the best inverters have included a 3-stage automatic battery charger and a transfer relay, thus simplifying the system. These inverters are more expensive, but they are worth buying because you will save money overall, as the cost of this included charger is minimal compared to that of an external charger.
Step 5. Get the cables, fuses and other materials to connect the batteries, charger and inverter
- They must be of good quality, well made and small enough to put them together, to minimize the resistance of the cable.
- Consider buying a connection bar with large dividers instead of having wires everywhere. It serves to order things well and to prevent accidents. It also helps to remove the batteries more easily.
Step 6. Put on your protective gear and comply with safety regulations
- Wear eye protection to protect yourself from acid splashes.
- He also wears protective insulated gloves.
- If you are wearing jewelry or metal objects, set them aside.
Step 7. Securely connect the charger cable to the deep-cycle battery, paying attention to polarity
Step 8. Prepare the loading system
Plug the charger into the power outlet and turn it on. Make sure that a proper charging cycle begins and that the inverter is turned off.
Step 9. Plug in and test the inverter if it is disconnected from the charger
Connect the cables to the batteries, paying attention to polarity. Turn on the inverter and test it with an adequate charge of alternating current. There should never be sparks, smoke or fire. Leave the inverter turned on with the charge you want and let the batteries charge overnight, so you will verify that the charger and the charge are suitable. In the morning, the batteries should be charged.
Step 10. Disassemble the trial implant
Step 11. Build a well-made cover
You can use shelves or a large container; it will be used to contain the batteries, the charger and the inverter. Generally, do not place the charger and inverter near the batteries, to avoid gas leaks coming into contact with them. If so, you could shorten the life of the electronic equipment, or create a fire caused by gas sparks, if there is not adequate ventilation. Some partitions must be installed separately and to ensure good ventilation to the charger and inverter. Alternatively, mount the charger / inverter outside the battery box. When it's ready, install the components into it.
Step 12. Make the connections
The cables must be short enough. It's good to have easy access to each battery, so fix and connect the cables well. For wet cells, you will need to be able to easily remove the lids to check fluid levels and fill them with distilled water. Make sure the inverter is grounded. You can do this with the ground wire on the AC charger input, or use a ground stake driven into the ground.
Step 13. Use alternative supplements where needed
You can replace or amplify the charger with solar, wind, etc., connected to their dedicated charging controller; it will serve to lengthen the duration by a lot. Also, you can amplify the charger with a generator. Connect a truck's alternator to a small combustion engine, use a generator with a charge output of 12 volts, or unplug the charger from the AC outlet and use a "regular" AC generator to power the charger.
- The UPS can be placed outdoors.
- Install a standalone indoor-outdoor outlet through the wall. You can connect the UPS to the external socket (using an extension cable and reductions) to power the internal socket.
- Disconnect and isolate an internal circuit from the thermal magnetic switch. Take the cable out of the box or remove it and connect it to the inverter, creating a protective conduit. All sockets, lights, smoke detectors etc. in that circuit they will be powered by the UPS, so do a test to make sure there is nothing else connected to the circuit.
- Use the electrical conduits as you wish, based on the solutions chosen.
- Do not wear watches or jewelry when handling batteries.
- Wear eye protection when handling batteries.
- Grounding the inverter is not optional - it is a must. Remember to respect local regulations regarding grounding, especially if you are entitled to only one stake per house.
- There is enough direct current in a battery to stop your heart beating.
- The inverter's AC output is similar to mains currents and can kill you.
- If you are not an experienced electrician, do not follow these steps.
- If the power goes into outdoor outlets or near water, buy an inverter with a differential switch or add one.
- Direct battery current can burn you. A ring that ends in the middle of "hot" cables can amputate your finger.
- Don't fiddle too much with the circuit breaker if you're not a good (and cautious) electrician.
- A short circuit to the batteries can create blinding flashes, shatter tools, blow up the battery which will emit sulfuric acid and pieces of plastic all over the place.
- It is recommended to wear shoes.
- Make sure the batteries have adequate ventilation. Trapped hydrogen could cause a fire and / or burst.
