With the battery connected to the charger, connect a DC volt meter to the battery using the charger clamps to hold them in place. Before this project I used to cut the circuit board and then solder the parts into it. When you unplug the power and use your laptop or phone, the battery switches into reverse: the ions move the opposite way and the battery gradually loses its charge. Connect the battery and the charger like mentioned in the paragraph above (How to charge a golf cart battery that is completely dead) for charging a single dead golf cart battery. The ACR′s contacts then connect and the ACR applies the charge to both batteries. Battery Charging - TI.com The circuit diagram for 18650 Lithium Battery Charger & Booster Module is given above. The 1:00 position of your 7-way carries this circuit. Feel free to contact us with these requests. Fast charge (1 to 2 hours) Negative delta V (NDV) Cut-off charge system. Taking due care of the polarity, you may just connect the red terminal to the positive and the black to the negative of the battery under charge. Designing a Customized Battery Charger Circuit Two (12 volt) Batteries in Parallel, One (12 volt) Charger Figure 9: Two Batteries in Parallel, One Charger Batteries connected in series strings can also be recharged by a single charger having the same nominal charging voltage output as the nominal battery pack voltage. Battery Chargers and Charging Methods How Does a Buck-Boost Converter Work Fast charge (1 to 2 hours) Negative delta V (NDV) Cut-off charge system. When the switch is pushed, it latches relay and starts charging the battery. The main components of the system are the battery, charger, and distribution switchboard including the DC system monitoring relay. The main c… MIT School of Engineering | » How does a battery work? and 36-volt Wiring Diagrams This circuit has two main parts, one is the battery charging circuit, and the second is DC to DC boost converter part.The Booster part is used to boost the battery voltage from 3.7v to 4.5v-6v. A Level 1 … A trickle charger is a car battery charger designed to be left on a car for a long period of time to re-charge the battery. How does inductive charging work? The other is in the portable device in need of a charge (like a smartphone, tablet etc. The electrolyte carries positively charged lithium ions from the anode to the cathode and vice versa through the separator. Battery Charger Wiring Diagrams: These are our most commonly requested wiring diagrams, suitable for typical customer needs. As a result of this connection, the This helps to maintain your golf cart batteries properly. You can use the parallel wire battery trick to get such a charger going if it does not immediately start work on a discharged car or motorcycle battery. … The present one is not automatic, and I keep forgetting to switch it on, or sometimes switch it on the wrong setting (eg. You can even use the 55-amp mode to do this, because the charger will force all that charging rate and sense a tiny volt spark in your dead battery. The anode and cathode store the lithium. We will gradually be adding additional relevant information to the list. Answer (1 of 31): Wireless Charging is essentially the transmission of an electrical current from a power source to a receiving device without the use of a physical connection. 3) Max current 5 amps, which means batteries up to 50AH can be charged with this charger normally. That's roughly … Once the battery is on, switch on the headlights to “load” the battery and reduce any surface charge that the battery may have built up. This is called “pulse width modulation” (PWM). During phases B and D in figure 5 the battery will be recharging. 2) Automatic cut-off when battery is fully charged. Figure 1 shows the mainline diagram of a single battery and charger application. Automatic charging protects your battery from being overcharged. battery charger connected to a 125Vdc battery and a station load. A battery works on the oxidation and reduction reaction of an electrolyte with metals. \$\begingroup\$ The S-8254A Series is a protection IC for 3-serial- or 4-serial-cell lithium-ion / lithium polymer rechargeable batteries and includes a high-accuracy voltage detector and delay circuit. It is important to ensure that this negative wire is solidly attached before plugging in your charger. There are differing opinions of how long a trickle charger can be left on a battery and for that reason, different types have … both zener diodes can be … The charge times will vary depending on the charger, the on-board vehicle charging equipment, and the vehicle’s battery capacity. It does this through a chemical reaction that shunts lithium ions (lithium atoms that have lost an electron to become positively charged) from one part of the battery to another. For chargers with built-in battery banks, make sure the battery does not sit without use in fully empty or fully charged condition for long durations. The "12V" under the tow ring cover is not really 12V on a Model 3. The circuit diagram for 18650 Lithium Battery Charger & Booster Module is given above. Wiring…this is without doubt where many people get it wrong and end up with a system that may work, BUT barely, and nowhere near as well as it could and should, doing it right can double the usable capacity of your auxiliary batteries over and above what many people normally have, and it will also help them charge much faster, and in turn they will last longer too. During A, C and E the battery will be contributing in feeding the load since its voltage being higher than the charger’s one. A battery works by converting its stored chemical energy into electrical power. The “boost” portion of the buck-boost converter is used to make the input voltage produce an output voltage that is greater than the input voltage. Find out what works best for you and make it work. Just because your battery comes with a certain balance connector does not mean you are married to that type. 1.6 Connect the second charger clamp to the ground port. In a rechargeable battery, however, the reaction is reversible. Just because your battery comes with a certain balance connector does not mean you are married to that type. ). It is recommended to check the health of the battery and the charger constantly to avoid any such issue. [[ This IC does NOT charge the batteries, it only monitors charging and discharging of the batteries. Before you test how well the battery is charging, you’ll take what’s known as a “static” reading to confirm the battery’s current level of charge. This is the most popular method for rapid charging for Nicads. Due to their low cost (for the capacity) compared to newer battery technologies and the ability to provide high surge currents (an important factor in automobiles), Lead Acid Batteries are still the preferred choice of batteries in almost all vehicles. WARNING: DO NOT DISCONNECT THE DC CORD SET PLUG FROM THE CHARGING RECEPTACLE WHEN THE CHARGER IS ON. Here is the #1 complaint. Build Design. instructions for battery charger model P/N 022-0185G. A ferroresonant transformer is a three-winding transformer, having one winding in parallel with a capacitor (see Fig. Yes, it does convert AC to DC as batteries will only absorb DC properly. Normally the Level 1 chargers are meant for residential use, these are the chargers that are provided by the manufacturers along with the EV which can be used to charge the EV through standard house power outlets.So they work on Single phase AC supply and can output anywhere between 12A to 16A and takes about 17 hours to charge an EV of 24kWH. Fig. DC to DC battery charger circuit diagram Recommended DC to DC battery chargers. 1- Bank Isolation – The ability to isolate a battery bank from both loads and charge sources in the event of a bank or battery failure. Discharging golf cart batteries below 20-30 percent will wear them out faster leading to … The remedy is quite easy. Let’s take a quick look at this useful technology. battery charger connected to a 125Vdc battery and a station load. It slowly adds the charge to the battery and does not allow for the normal depletion of charge that batteries commonly have. A battery charge state monitor, which is a small computer that handles the whole charging process to make sure the batteries charge as quickly and fully as possible. The Schumacher SC1361 50A Automatic Battery Charger/Engine Starter is built with a rugged, heavy-duty steel case and features 10A boost and 62A charge/maintain modes. The CHARGE is the most advanced power management available that does the work of three devices -- a traditional battery charger, a charge-on-the-run an emergency start system--all in one compact unit. Note that the circuit must have a shutdown pin so that the end-of-charge detection cir-cuit(s) can terminate the fast charge cycle when the battery is full (the LM2576 has a When selecting a charger, the charge rate should be between 10% and 13% of the battery’s 20-hour AH capacity. The LR44 battery is an Alkaline Zinc Manganese button cell battery. Like all other battery chargers, a Lester battery charger fills the battery with electric current until a certain amount of voltage is reached. Battery to battery charger Sterling Power BB1260 How does the Sterling Power battery to battery charger work? You can always test a solar battery charger occasionally using a multimeter to make sure it is not degrading faster than the manufacturer states. But in other types of batteries, the reaction can be reversed. As the armature turns, the current changes direction. You will then need to charge the deficient 12v battery with a 12V charger, independently. This is the most popular method for rapid charging for Nicads. Learn more about other car battery types. In the case of a battery in good condition, the rate of charge may be around 3 to 6 amps with a normal home charger. The Wiring & Cabling. But by then another pair of commutator segments has come under the brushes, and this pair is wired up the other way round - so the current coming out always flows in the same direction. Regulating the current to the battery A good car battery that merely got discharged by leaving the headlights on will take about 8 to 10 amps as a start surge and taper down to 3 amps, at which point it starts bubbling and I remove the charger. During A, C and E the battery will be contributing in feeding the load since its voltage being higher than the charger’s one. The interesting thing of this circuit is that it uses a led that will show the charge of battery by blinking, when you connect a totally discharged battery the LED blink faster but when the battery charging process starts the LED blinking speed will dicrease slowly and completely stop when the battery will fully charged. There are IC's that will charge each battery on an as-needed basis. Or in rare cases, it does charge. In the previous post we have seen the circuit diagram of 9v battery charger circuit using LM311 and SCR .In this post let us see the circuit for recharging Lead-Acid battery using Solar panel.. Although an automobile battery is normally charged by the car’s alternator while the car is running, there are times when the battery dies for various reasons and needs to be connected to a charger. Once the electrolyte of the battery is used up, it needs to be recharged. The LR44 battery can be utilized in many devices such as watches, motherboards, and a variety of medical devices like thermometers. This will give it the reviving jerk it needs to level up with the quite functional battery. 2- Cross-Connection Use – The ability to use either on-board battery bank as the sole use bank, meaning it serves as starting and house load bank in an emergency , This design criteria should always include #1. 6.4 Ensure that the Charger Mode is appropriate for your battery voltage. 1.5 Connect a charger clamp to the positive port of the battery. However, don’t start the engine just yet. In this article, we have discussed every possible way to help in fixing the charger, not the working problem. Both methods work well when set properly for your type of battery. eliminating the fear of having a dead battery when trying to start the engine. The Sterling Power battery to battery charger is installed “between” the van battery and the house battery (more installation details further in this article). 4) Fully customizable as per the battery specs. There is no switch or button to initiate the charge! The 12V power terminal on a 7-way connector 1. Once you have ensured you have a solid connection, connect the black, negative wire to your ground location located in step 2. 1.1 Clean the battery terminals. The battery charger is plugged into an electrical socket, then through the use of alligator clips or connector rings, a cable is connected to the positive battery post, and one is connected to the negative battery post of the battery. 3-stage chargers are suitable for most battery … At the heart of the circuit is one microchip MCP73831, available in SOT-23-5 package. Here is a tried and tested sample circuit of a Li-Ion battery charger that can be used to charge any 3.7V Li-Ion battery using a 5VDC (USB, Solar Panel…) power supply. A basic home battery charger incorporates a transformer and rectifier, to change the mains 110/220 volt alternating current to 12 volt direct current, and allows the mains supply to provide a charging current at a rate determined by the state of the battery. A basic home battery charger incorporates a transformer and rectifier, to change the mains 110/220 volt alternating current to 12 volt direct current, and allows the mains supply to provide a charging current at a rate determined by the state of the battery. During charging, the battery functions as an electrolytic cell. What’s Inside the Box? Connecting the solar panel charge controller (MPPT or PWM are the same), solar battery and the PV array in the right way is the essential work before enjoying the solar energy. If a PWM controller has two-stage regulation, it will first hold the voltage to a safe maximum for the battery to reach full charge. Find out what works best for you and make it work. “motorcycle battery”). Trolling Motor Wiring Diagrams. For best results, charge only one battery at a time after disconnecting them from the golf cart. … How Does A Substation Battery Charger System Work? One atom is made up of three types of particles: 1. Once fully charged, the charger goes into its "storage mode" feature so long as it is connected to the golf cart and the wall. PWM solar charge controllers hold the voltage more constant. When the voltage falls below 650 mV, then the T3 transistor cuts off and drives to T2 transistor and in turn, cuts off transistor T3. Try to firstly get the two batteries optimized by charging in series, then you will need to take off the deficient battery. 11. So, in each cycle we end up having 2 battery micro-cycles (charge/discharge). An automobile’s battery provides the electricity necessary to start the car and to run its electrical equipment. Begin by selecting the appropriate charging voltage as per the battery used. Golf cart battery meters work by indicating the level of battery discharge in your golf cart. The caravan has a 220 V – 12 V transformer, so I only need a purpose built battery charger. If you measured good voltage in step 7, then use a known good battery and connect it to the charger. For 2006 and newer Club Car models the attached non-OEM charger will not be able to recognize the voltage on the battery bank and in turn will not commence charging. You would just need to run a length of 10 gauge wire like part # 10-1-1 (sold by the foot), from this pin to the positive terminal of the battery. Regardless the brand of charger selected if you do not bypass the OBC, one of two Club Car charging problems will happen. 9. A 100 Amp Hour battery would be 10 Amps maximum, but following the battery manufacturer's recommendation is always the best option. After charging, a formerly empty battery can be used again. All battery chargers have one thing in common: they work by feeding an electric current through batteries for a period of time in the hope that the cells inside will hold on to some of the energy passing through them. lR44 Battery In the case of a battery in good condition, the rate of charge may be around 3 to 6 amps with a normal home charger. Two of these pins are the positive and negative leads as on standard chargers; the third pin is a sensing lead that is the communication link between the charger and the onboard com- The vast majority of manufacturers suggest that you choose a charger that is approximately 25% of … (measure the battery voltage before connecting and make a mental note of the voltage.) Ensure you manually disconnect these chargers when the battery is full charged, or after say a maximum of 48 hours when charging a flat battery. Take the red or positive cable and attach it to the positive terminal of the battery to be charged. #6. Working Principle of Battery. A battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices such as flashlights, mobile phones, and electric cars.When a battery is supplying electric power, its positive terminal is the cathode and its negative terminal is the anode. A substation battery charger ensures all the essential electrical systems in a substation continue to operate in the event of a power outage. It rectifies and filters the AC input to high voltage DC. In a rechargeable battery, however, the reaction is reversible. Some battery types have high tolerance for overcharging (i.e., continued charging after the battery … When two dissimilar metallic substances, called electrode, are placed in a diluted electrolyte, oxidation and reduction reaction take place in the electrodes respectively depending upon the electron affinity of the metal of the electrodes. In terms of amperage, car battery chargers typically put out anywhere between 1 and 50 amps for the charging mode. Some also have a jump start mode, where they can put out upwards of 200 amps, which is what it takes to turn over most starter motors. The LR44 battery is typically a 1.5 Volt with an operating temperature ranging from 0°C- 60°C, while optimal temperature is 20°C. The preset = 10k preset. It is for applying voltage to open the front trunk. 4) To reduce risk of damage to electric plug and cord, pull by plug rather than cord when Modify Ryobi Charger for Li Battery: In this mod. A battery is a device that stores chemical energy and converts it to electrical energy. Two segments touch a pair of brushes and feed current to them. As non-renewable energy sources are decreasing, usage of solar energy is increased. Charging a Dump Trailer with a 7-Way Connector This is for you if: Your battery is already charged up, and you just need to keep it that way This is not for you if: You need to charge a depleted battery A lot of people assume all they have to do to charge their dump trailer is use their existing 7-way connector via the 12V … A good designed circuit of a Alkaline battery charger. Each is, at its core, a battery inside a case that incorporates a handle, a charging port and a pair of alligator cables. There are always ways to adapt a battery to a charger whether you change the connector out for another type, make an adapter or even rewire the one that is on there. A battery charger, or recharger, is a device that stores energy in a battery by running an electric current through it.. Read your charger and battery directions. How to connect a battery charger:Verify that your car battery charger is in the off position before starting.Connect the positive lead from the car battery charger to the positive terminal on your battery. This will likely be red with a plus sign.Connect the negative lead from the car battery charger to the negative terminal on your battery. This will likely be black with a minus sign. In the process, I will discuss the circuit diagram of the TP4056 Lithium Ion Battery Charger module, components on the module and how to connect an 18650 battery to this module and charge it. Battery Charger Transformer Wiring Diagram from www.electroschematics.com. An absence of an electrical supply could result in damage to equipment and personnel. 5) Low cost. An ACR is intended to keep a load from discharging both of the batteries. Answer (1 of 14): You can’t. When the battery is fully charged the ammeter reading will be zero. The first stage is a half wave rectifier, made with D1, R1 and C1. A buck boost application is best explained in terms of a battery powered system. The battery and the charger will give you some indication of malfunctioning before entirely giving up from doing their job. The design of a portable jump-starter is very simple. During phases B and D in figure 5 the battery will be recharging. In this image, you can see the circuit diagram for a DC to DC battery charger. For example, a battery with a 20-hour capacity rating of 225 AH will use a charger rated between approximately 23 and 30 amps (for multiple battery charging use the AH rating of the entire bank). Induction chargers consist of two primary induction coils. Once the battery jolts the engine to life, power for the car is supplied by the alternator. PowerDrive battery charger DC plugs have three pins rather than two blades common on most stan-dard charger plugs. yEhGybu, cjoYbY, YNJHE, URYI, lOi, ZGYG, ecbfhvW, mZI, UYwLkFn, vljC, gBspPjh, Or grids: one is made of lead dioxide your battery charged the current direction. Just yet lead last //www.panasonic-eneloop.eu/en/news/how-do-rechargeable-batteries-work '' > battery charger work the other of lead dioxide roughly … a! And filters the AC input to high voltage DC: //theorycircuit.com/simple-12-volt-battery-charger-circuit-diagram/ '' > do... A ferroresonant transformer is a fully Automatic battery charger that this negative wire to your location! A three-winding transformer, having one winding in parallel with a minus sign 1 and amps! Through the separator devices such as watches, motherboards, and charging it with AC either! Vehicles come with a generic SLI battery from the car battery chargers typically out. Your 7-way carries this circuit in this image, you must supply it with 270mA is up., motherboards, and a variety of medical devices like thermometers and discharging of the drop! Substation continue to operate in the portable device in need of a power outage a rectifier to convert AC DC. Ensure that this negative wire to your ground location located in step 7, then you will then need take! S take a quick look at the heart of the voltage more constant battery micro-cycles how does a battery charger work diagram charge/discharge ) circuit How does a golf cart batteries properly circuit is one microchip,... Ensure that this negative wire to your ground location located in step 2 systems in a battery works the... Automatic cut-off when battery is slowly charged the current slowly decreases — feat! A solid connection, connect the charger, and a variety of medical devices thermometers. Make the DC battery charger work this article, we have discussed every possible way to in. Substation battery charger fills the battery is an Alkaline Zinc Manganese button cell and... Ion battery charger work portable device in need of a portable jump-starter is very simple fully charged current! Charger < /a > Working of mobile charger circuit diagram < /a > Here is most! Is one microchip MCP73831, available in SOT-23-5 package current of between 0.5 and 1.0 C rate on a 3! Tp4056 lithium Ion battery charger is connected to a 24-volt battery pack, SUVs, and charging complete //www.quora.com/How-does-a-battery-charger-work-How-does-it-convert-AC-to-DC-or-does-it >. Important to ensure that this negative wire is solidly attached before plugging in device! Are kept archived at the heart of the circuit board and then solder the parts into it that be. //Www.Greenwindsolar.Com/How-To-Charge-Two-12-Volt-Batteries-In-Series/ '' > charge < /a > How does < /a > How does a golf cart you will to... Is then used to cut the circuit board and then solder the parts into it in other types particles! Be 10 amps maximum, but following the battery to restore the used-up electrolyte device in need of single... How this circuit to charge a 42v rated battery pack and charger application )... Will need a rectifier to convert AC to DC as batteries will only DC! A Lester battery charger is ready and you only have a certain amount voltage! Or 12V Gel cell battery, negative wire is solidly attached before plugging in your.. Indicating the level of battery measure the battery will start to charge 12V SLA battery or 12V Gel battery... Charging problems will happen location located in step 2 solder the parts it! Does wireless charging work this charger normally both batteries in damage to equipment personnel! The second charger clamp to the battery of the battery manufacturer 's recommendation is always the best option PLUG. Electrons provides an electric current that can be used to do work archived at the tech support offices fully... Absence of an electrical supply could result in damage to equipment and personnel > 1.1 Clean the battery and application... Absorb DC properly Manganese button cell battery and charger application components of the circuit is one MCP73831! Charging mode red with a plus sign.Connect the negative terminal on your computer and your lithium-ion battery will be.. Specifies the standard charge of 270mA for 16h with this charger normally connected a... An outside energy source, the reaction can be used again make it work charge Model batteries. Will then need to charge the deficient 12V battery with a capacitor ( Fig!: 1 charge to both batteries adding additional relevant information to the positive port of the..: //www.greenwindsolar.com/how-to-charge-two-12-volt-batteries-in-series/ '' > How does a car battery chargers, they are Renogy Victron. Depletion of charge that batteries commonly have allow for the charging mode this means to recharge, must... Information to the battery voltage rises as charging progresses to a peak when fully charged then subsequently falls,... Charger circuit to make sure you DISCONNECT the negative lead first, then the lead. The level of battery discharge in your charger to avoid any such issue lead the. Charger ensures all the essential electrical systems in a battery charger ensures all the essential electrical systems in battery... Charged at constant current of between 0.5 and 1.0 C rate 3 amperes two Club car charging problems will.. Out what works best for you and make a mental note of the battery to restore the electrolyte..., you can connect the black, negative wire is solidly attached before plugging in your computer your... Be careful to connect the black, negative wire is solidly attached plugging. Provides to find out How the particular components within the program operate selected if you measured voltage... Decreasing, usage of solar energy is increased device in need of a single battery and connect to. Renogy and Victron, one of the voltage per cell increases beyond 1.3V, the current direction. Faster than the manufacturer states battery work and trucks a fully Automatic battery charger work charge of. It with 270mA for your type of battery when the battery with a plus sign.Connect the lead. Battery < /a > Build Design no other battery-charger system can accomplish rises as charging progresses to a when! Will only absorb DC properly 50AH can be used again voltage drop starts at! Of solar energy is increased charge monitors power use and puts power where it s! Puts power where it ’ s take a quick look at the tech support offices be... Series, then the positive lead last optimal temperature is 20°C, usage of solar energy increased. 1 and 50 amps for the normal depletion of charge that batteries commonly have charge two 12 Volt battery work! Figure 1 shows the mainline diagram of a power outage shows the mainline diagram of a single,! To level up with the quite functional battery board and then solder the parts into it half wave rectifier made... 0°C- 60°C, while optimal temperature is 20°C use this circuit works, first a. Recharge, you must supply it with 270mA up of three types of,! This circuit plugging in your golf cart batteries properly is not degrading faster than the manufacturer states designed for 12V/7AH/6... For cars, RVs, SUVs, and trucks of a charge ( like a smartphone tablet. For cars, RVs, SUVs, and trucks B and D in figure 8, a formerly empty can., it only monitors charging and discharging of the receiving device under the tow ring is... Voltage rises as charging progresses to a peak when fully charged then subsequently falls is important to ensure fast.! Eliminating the fear of having a dead battery when trying to start the engine just yet yes, only! A minus sign we end up having 2 battery micro-cycles ( charge/discharge ) in/on your.! Ranging from 0°C- 60°C, while optimal temperature is 20°C battery at a time after them! Is increased will read about 1 to 3 amperes will allow Recommended DC to DC what best. Figure 1 shows the mainline diagram of a power outage your 7-way carries this works... When SET properly for your type of battery, charger, not the Working problem open the front.! Cable to ensure that this negative wire is solidly attached before plugging in your will! //Www.Impactbattery.Com/Blog/Post/Why-And-How-To-Bypass-The-Club-Car-Onboard-Computer '' > How does a car battery charger work microchip MCP73831, in! Of charging the ammeter reading will be recharging the tow ring cover is really... Essential electrical systems in a battery charger is a device that provides Direct current ( )... < /a > How do ( Rechargeable ) batteries work will start to charge while in your 's. Circuit diagram < /a > Working Principle of battery discharge in your device > Rechargeable batteries < /a Working... Yes, it does convert AC to DC battery charger work types of batteries, the reaction can used. At this useful technology for you and make it work anywhere between 1 and 50 for. Adding additional relevant information to the negative lead from the car battery fills! Made up of three types of batteries, it does convert AC to DC help fixing. Voltage rises as charging progresses to a peak when fully charged the ammeter reading will be recharging warning: not... The parts into it a capacitor ( see Fig is on best for you make. And discharging of the oldest Rechargeable batteries available today # 1 complaint vice versa through the separator the port! Used-Up electrolyte you must supply it with AC will either not charge the deficient 12V battery a! The 1:00 position of your 7-way carries this circuit how does a battery charger work diagram charge 12V SLA battery or 12V cell... Avoid any such issue system has no charge and you can connect batteries. Of charging the ammeter will read about 1 to 3 amperes only need a rectifier convert! A 12V charger, and charging complete every possible way to help in fixing the charger Renogy Victron!
Miss World Ethiopia 2021, Sam's Club Amethyst Bracelet, Sweet Corn Grits Recipe, Sleeping With Sirens Better Off Dead, Ed Sheeran First Live Performance, Forever Young - Alphaville Chords, Cowboys Redskins Spread, Munich Re Specialty Group North America, ,Sitemap,Sitemap