Feflo's Posts
Nairaland Forum › Feflo's Profile › Feflo's Posts
1 2 3 4 5 6 7 8 ... 50 51 52 53 54 55 56 57 58 (of 81 pages)
 Technology Market › Re: World's Smallest Power Inverter by feflo(op): 4:32pm On Jul 30, 2016 |
Amp-Hours - What Are They? All deep cycle batteries are rated in amp-hours. An amp-hour is one amp for one hour, or 10 amps for 1/10 of an hour and so forth. It is amps x hours. If you have something that pulls 20 amps, and you use it for 20 minutes, then the amp-hours used would be 20 (amps) x .333 (hours), or 6.67 AH. The generally accepted AH rating time period for batteries used in solar electric and backup power systems (and for nearly all deep cycle batteries) is the "20 hour rate". (Some, such as the Concorde AGM, use the 24 hour rate, which is probably a better real-world rating). This means that it is discharged down to 10.5 volts over a 20 hour period while the total actual amp-hours it supplies is measured. Sometimes ratings at the 6 hour rate and 100 hour rate are also given for comparison and for different applications. The 6-hour rate is often used for industrial batteries, as that is a typical daily duty cycle. Sometimes the 100 hour rate is given just to make the battery look better than it really is, but it is also useful for figuring battery capacity for long-term backup amp-hour requirements. Why amp-hours are specified at a particular rate: Because of something called the Peukert Effect. The Peukert value is directly related to the internal resistance of the battery. The higher the internal resistance, the higher the losses while charging and discharging, especially at higher currents. This means that the faster a battery is used (discharged), the LOWER the AH capacity. Conversely, if it is drained slower, the AH capacity is higher. This is important because some manufacturers and vendors have chosen to rate their batteries at the 100 hour rate - which makes them look a lot better than they really are. Here are some typical battery capacities from the manufacturers data sheets: Battery Type 100 hour rate 20 hour rate 8 Trojan T-105 250 AH 225 AH n/a US Battery 2200 n/a 225 AH 181 AH Concorde PVX-6220 255 AH 221 AH 183 AH Surrette S-460 (L-16) 429 AH 344 AH 282 AH Trojan L-16 400 AH 360 AH n/a Surrette CS-25-PS 974 AH 779 AH 639 AH State of Charge Here are no-load typical voltages vs state of charge (figured at 10.5 volts = fully discharged, and 77 degrees F). Voltages are for a 12 volt battery system. For 24 volt systems multiply by 2, for 48 volt system, multiply by 4. VPC is the volts per individual cell - if you measure more than a .2 volt difference between each cell, you need to equalize, or your batteries are going bad, or they may be sulfated. These voltages are for batteries that have been at rest for 3 hours or more. Batteries that are being charged will be higher - the voltages while under charge will not tell you anything, you have to let the battery sit for a while. For longest life, batteries should stay in the green zone. Occasional dips into the yellow are not harmful, but continual discharges to those levels will shorten battery life considerably. It is important to realize that voltage measurements are only approximate. The best determination is to measure the specific gravity, but in many batteries this is difficult or impossible. Note the large voltage drop in the last 10%. State of Charge 12 Volt battery Volts per Cell 100% 12.7 2.12 90% 12.5 2.08 80% 12.42 2.07 70% 12.32 2.05 60% 12.20 2.03 50% 12.06 2.01 40% 11.9 1.98 30% 11.75 1.96 20% 11.58 1.93 10% 11.31 1.89 0 10.5 1.75 |
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 4:29pm On Jul 30, 2016 |
Battery Voltages All Lead-Acid batteries supply about 2.14 volts per cell (12.6 to 12.8 for a 12 volt battery) when fully charged. Batteries that are stored for long periods will eventually lose all their charge. This "leakage" or self-discharge varies considerably with battery type, age, & temperature. It can range from about 1% to 15% per month. Generally, new AGM batteries have the lowest, and old industrial (Lead-Antimony plates) are the highest. In systems that are continually connected to some type charging source, whether it is solar, wind, or an AC powered charger this is seldom a problem. However, one of the biggest killers of batteries is sitting stored in a partly discharged state for a few months. A "float" trickle charge should be maintained on the batteries even if they are not used (or, especially if they are not used). Even most "dry charged" batteries (those sold without electrolyte so they can be shipped more easily, with acid added later) will deteriorate over time. Max storage life on those is about 18 to 30 months. Batteries self-discharge faster at higher temperatures. Lifespan can also be seriously reduced at higher temperatures - most manufacturers state this as a 50% loss in life for every 15 degrees F over a 77 degree cell temperature. Lifespan is increased at the same rate if below 77 degrees, but capacity is reduced. This tends to even out in most systems - they will spend part of their life at higher temperatures, and part at lower. Typical self-discharge rates for flooded are 5% to 15% per month. Myth: The old myth about not storing batteries on concrete floors is just that - a myth. This story has been around for 100 years, and originated back when battery cases were made up of wood and asphalt. The acid would leak from them, and form a slow-discharging circuit through the now acid-soaked and conductive floor. State of Charge State of charge, or conversely, the depth of discharge (DOD) can be determined by measuring the voltage and/or the specific gravity of the acid with a hydrometer. This will NOT tell you how good (capacity in AH) the battery condition is - only a sustained load test can do that. Voltage on a fully charged battery will read 2.12 to 2.15 volts per cell, or 12.7 volts for a 12 volt battery. At 50% the reading will be 2.03 VPC (Volts Per Cell), and at 0% will be 1.75 VPC or less. Specific gravity will be about 1.265 for a fully charged cell, and 1.13 or less for a totally discharged cell. This can vary with battery types and brands somewhat - when you buy new batteries you should charge them up and let them sit for a while, then take a reference measurement. Many batteries are sealed, and hydrometer reading cannot be taken, so you must rely on voltage. Hydrometer readings may not tell the whole story, as it takes a while for the acid to get mixed up in wet cells. If measured right after charging, you might see 1.27 at the top of the cell, even though it is much less at the bottom. This does not apply to gelled or AGM batteries. "False" Capacity A battery can meet the voltage tests for being at full charge, yet be much lower than it's original capacity. If plates are damaged, sulfated, or partially gone from long use, the battery may give the appearance of being fully charged, but in reality acts like a battery of much smaller size. This same thing can occur in gelled cells if they are overcharged and gaps or bubbles occur in the gel. What is left of the plates may be fully functional, but with only 20% of the plates left... Batteries usually go bad for other reasons before reaching this point, but it is something to be aware of if your batteries seem to test OK but lack capacity and go dead very quickly under load. On the table below, you have to be careful that you are not just measuring the surface charge. To properly check the voltages, the battery should sit at rest for a few hours, or you should put a small load on it, such as a small automotive bulb, for a few minutes. The voltages below apply to ALL Lead-Acid batteries, except gelled. For gel cells, subtract .2 volts. Note that the voltages when actually charging will be quite different, so do not use these numbers for a battery that is under charge. 1 Like |
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 12:30pm On Jul 30, 2016 |
Old inverter installation at lamgbasa, Ajah, Lagos. 1 Like
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 9:15am On Jul 30, 2016 |
Battery Maintenance Deep cycle batteries (lead-based) such as those used in off-grid solar power systems have much thicker lead plates than car batteries to make them last longer. Deep cycle batteries should never really be discharged to below 20% of their full capacity, because internal resistance causes heat and damage when they are recharged. Renewable energy systems usually use a low-charge or low voltage warning light or a low-voltage cut-off switch to prevent the type of damage that will shorten the battery’s life. Battery shelf life can be extended by storing them at a lower temperatures, because the chemical reactions in the batteries are slower. However, in order to reach their maximum voltage, batteries must be returned to room temperature. Therefore, most deep cycle battery manufacturers do not recommend refrigerating batteries. While conventional deep cycle battery systems generally require a significant amount of oversight, the next generation of energy storage (lithium-ion) features highly automated management systems; with maintenance and monitoring basically nil. Battery safety, explosions and other hazards A battery explosion is caused by the misuse or malfunction of a battery, such as attempting to recharge a non-rechargeable battery or short circuiting a battery. Explosions are most likely to occur when a short circuit generates very large currents. In addition, deep cycle batteries can release hydrogen when they are overcharged (due to electrolysis of the water in the electrolyte). Normally the gas dissipates quickly. However, this gas can be ignited by a nearby spark (for example, when removing the jumper cables). Note: hydrogen gas production isn’t an issue with lithium-ion batteries. Attempting to charge a battery beyond its electrical capacity, ie overcharging, can also lead to a battery explosion, leakage, or irreversible damage to the deep cycle battery. It may also cause damage to the components in which the overcharged battery is used. When a conventional battery is recharged at an excessive rate, an explosive gas mixture of hydrogen and oxygen may be produced faster than it can escape from within the walls of the battery, leading to pressure build-up and the possibility of the battery case bursting. In extreme cases, the battery acid may spray violently from the casing of the battery and cause injury. Deep cycle batter explosions can also occur in maintenance free lead-acid batteries if the valves fail or are blocked. The pressure rises within the cells until a short-circuit ignites the hydrogen-oxygen mixture. Such explosions can cause severe injury. The problem can be detected in most batteries if the sides appear swollen, or if the battery feels hot to touch. Culled from http://www.energymatters.com.au |
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 9:09am On Jul 30, 2016 |
Sealed Lead Acid Batteries Sealed lead acid batteries are also known as valve regulated lead acid (VRLA) batteries, recombinant batteries and often called maintenance-free lead-acid batteries. Examples of VRLA batteries are: • Absorbed glass mat (or AGM) • Gel cells The term “seal lead acid battery” is misleading: a sealed battery would be a safety hazard due to overpressure risks the battery is overcharged. There is always a safety valve present, hence the name valve-regulated. Even the term “valve regulated” does not really describe this technology. These are really “recombinant” batteries. This means that oxygen evolved at the positive will mostly recombine with the hydrogen ready to evolve on the negative and thus prevent water loss. The valve is only a safety feature in case dangerous amounts of hydrogen are produced. Flooded Lead Acid Batteries Flooded lead acid batteries, or wet cells, are the oldest type of rechargeable battery still in use. This type of battery contains a liquid in an unsealed container. This means that the battery must be kept upright and in a well-ventilated area to ensure safe dispersal of the hydrogen gas produced by these batteries during overcharging. The lead-acid battery is also very heavy for the amount of electrical energy it can supply. Flooded lead acid batteries require period monitoring and topping up with distilled water. Despite these disadvantages, flooded batteries have high surge current, easier to troubleshoot and are relatively inexpensive. Gel Batteries A gel battery (also known as a “gel cell”) is a sealed valve regulated lead-acid deep cycle battery and has a gel electrolyte. Unlike flooded lead-acid (wet cell) batteries, these batteries do not need to be kept upright. Gel cells virtually eliminate evaporation of the electrolyte, spillage (and subsequent corrosion issues) common to the flooded lead acid battery, and boast greater resistance to extreme temperatures, shock, and vibration. As a result, they are often used in automobiles, boats, aircraft, and other motorized vehicles. Culled from http://www.energymatters.com.au |
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 9:02am On Jul 30, 2016 |
AGM Batteries Absorbent glass mat (AGM) is a class of lead-acid deep cycle battery in which the electrolyte is absorbed into a fiberglass mat. The plates in an AGM battery may be flat like wet cell lead-acid battery, or they may be wound in a tight spiral. The internal resistance of AGM batteries is lower than traditional cells, they can handle higher temperatures, and self discharge more slowly. These batteries have a valve which will activate when the battery is recharged at high voltage. Valve activation allows some of the active material to escape thus decreasing the overall capacity of the battery. The lids /vents typically have gas diffusers built into them that allow safe dispersal of any excess hydrogen that may be produced during charging. They are maintenance free; and they can often be oriented in any manner, unlike normal lead-acid batteries which must be kept upright to avoid acid spills and to ensure the plates are sitting in the electrolyte. AGM batteries are totally sealed and are easy and safe to transport They never need topping up with water They can be safely mounted inside a boat, car, caravan, motorhome etc AGM batteries only need to be vented to atmosphere, they do not need to be in a sealed box vented to the outside like wet batteries, and can be mounted on their sides or ends if needed. Due to their very low internal resistance AGM batteries will fully charge at a lower voltage, and accept a much larger charge current, so when charging from a standard car/truck alternator these batteries will all but fully charge, and they will charge quickly, in about 3 hours! AGM batteries can be discharged deeper than conventional deep cycle batteries without major damage. AGM batteries only self discharge at the rate of up to 3% per month, and even after 12 months sitting idle can be recharged and put back into full service without any major damage. (A standard deep cycle battery if treated the same way will have destroyed itself, it will no longer hold a good charge) AGM batteries were originally developed for the military, they are very robust. Culled from http://www.energymatters.com.au |
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 8:55pm On Jul 29, 2016 |
More batteries
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 4:27pm On Jul 28, 2016 |
Dtarmon:This is one of my most simple inverter solutions and it cost 60k plus installation within Lagos.
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 4:23pm On Jul 28, 2016 |
tjsadiq:500watts solar installation which is recommended wattage for this setup will cost you 250k. Throw that amount into the mix and you get 310k
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 9:48am On Jul 28, 2016*. Modified: 4:16pm On Jul 28, 2016 |
oparaeke:40k sir. many thanks
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 11:08am On Jul 27, 2016 |
Battery bank
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 8:51am On Jul 26, 2016 |
Inverter
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 10:08am On Jul 25, 2016 |
North star 12vdc 100ah still very much available
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 8:58am On Jul 25, 2016 |
chris81964:I really don't get what you mean by "wrapped in plastic", if you are referring to the nylon at the top then i purposely left it there to prevent the lettering on the control button from peeling off. If you observe closely you will see that the air ducts are free thus the inverter is well ventilated. The installation was done in 2013 and i just replaced the batteries recently. Many Thanks |
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 2:36pm On Jul 24, 2016 |
Dtarmon:It was an old installation, I installed it in 2013. I seriously doubt if the inverter is still in the market There are other options available if you are really interested. |
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 5:08pm On Jul 23, 2016 |
feflo: |
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 6:58am On Jul 23, 2016 |
Cyberpower 2kva
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 3:15pm On Jul 22, 2016 |
Tutorial on How Many Batteries & Why This question comes up a lot so I thought I would take a couple of minutes to explain How and Why. The how is really a simple formula. The first step and most crucial is to determine how many watt hours you will need in a 24 hour period. You then multiply that number by 1.5 which is a fudge factor to account for charge/discharge efficiency, power factor, and inverter efficiency. If no inverter is involved then use 1.3. This will give you your adjusted watt hours per day. So for example let’s say you will use 3000 or 3 Kwh per day. 1.5 x 3000 wh = 4500 or 4.5 Kwh per day. The second step is to determine how many days of reserve capacity are required. The minimum is 2.5 days and up to 14 days. Then multiply this by 2 (for 50% depth of discharge as you never ever want to discharge more than 50%). So let’s select the minimum of 2.5 days. 2.5 days x 2 = 5 days. Third step is to take the number of days determined from step two, and multiply by the adjusted daily watt hour usage. So in this example 4500 wh x 5 = 22,500 wh or 22.5 Kwh. The last step is to divide the watt hour figure in step three by the battery system voltage. So now we must decide on a battery voltage of 12v, 24v, 36v, 48v, 60v and so on with multiples of 12 volts. For consumer grade applications the highest voltage (limited by equipment available to the public) is around 48 to 60 volts. Commercial applications can go as high as 500 volts and higher with special exemptions by limiting access to only qualified personnel. The voltage you choose is restricted mainly by the charge controller current capacity vs the solar panel wattage. Basically you want to use as high of voltage as you can afford to minimize power losses on the wring, and to keep the wiring as small as possible to minimize cost. For example the largest charge controller current available today to consumers is 80 amps. These controllers can be used on 12, 24, 36, and 48 volt systems. So a typical MPPT charge controller of 80 amps will have solar panel wattage limitations. For example at: * 12 Volts max panel wattage = 1000 watts * 24 Volts = 2000 watts * 36 Volts = 3000 watts * 48 volts = 4000 watts Culled from solarpaneltalk.com 1 Like |
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 10:08am On Jul 22, 2016 |
turok:1pc fairly new 12v 200ah batteries One 650va converted inverter One 10amps 12vdc charger Installation Total cost - 60k
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 7:18pm On Jul 21, 2016 |
Still selling one of my most affordable solutions
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 7:39pm On Jul 20, 2016 |
Still selling Safepower 1.5kva with enclosed plàstic rack
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 7:21pm On Jul 20, 2016 |
The demand for the converted APC UPS 1.5kva is skyrocketing. I do more of this installation than regular inverter.
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 4:50pm On Jul 18, 2016 |
Batteries
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 4:05pm On Jul 17, 2016 |
inverter
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 5:49pm On Jul 15, 2016 |
feflo: |
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 7:34pm On Jul 14, 2016 |
electronic:Using four new batteries will cost you 450k. Note that this price will not be thesame in 7days from today. Many thanks |
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 9:06am On Jul 14, 2016 |
Converted UPS
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 7:39am On Jul 13, 2016 |
Solar panels
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 1:48pm On Jul 10, 2016 |
Battery bank
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 8:07pm On Jul 09, 2016 |
Inverter
|
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 8:01pm On Jul 09, 2016 |
turok:Ok, noted, thanks. |
| Technology Market › Re: World's Smallest Power Inverter by feflo(op): 5:25pm On Jul 09, 2016 |
turok:You definitely need a charger. A UPS comes with small batteries, 12ah max and thus the inbuilt charger is designed to charge that capacity. Converting to inverter, you will be using the UPS with bigger battery capacity, 100ah or 200ah, an external charger is required to handle that capacity of battery. The maximum battery capacity is determined by what your charger can handle. Thanks |
1 2 3 4 5 6 7 8 ... 50 51 52 53 54 55 56 57 58 (of 81 pages)