# Tag Info

1

I have a similar setup, 400w pannels in series to give me a 48v-60v charge, 30amp mppt to 4 x 100amph in series giving me 48v 100amph. From there I tap off 48v to a 3.6kw 220 inverter, also taping of the 48v side have a 36 V to 75 V input to 12v output. On the 12v I run 5amp freshwater pump, 5amp saltwater pump, small bulge pump and around 100w of LED ...

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12 volts battery: max voltage is around 13.1V - 13.3V & min voltage is around 11.1V - 11.3V 7 AH: Battery can deliver less than 7 Amps for an hour or 1 Amp for 7 Hours. If the battery is fully charged it contains max voltage and 7 AH capacity. As u go on discharging the voltage and capacity go on reducing.

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If you read the datasheet, it gives information on the typical and maximum current consumption for the IC. It also gives power down consumption and other details. I'd also check the other documentation (app notes, etc) to see if there is more information/advice on power characteristics. On page 3 note 7, it says typical current consumption is below 100mA. ...

3

The datasheet is INCORRECT! but your understanding is not so far off... The battery capacity of 7Ah, x its voltage (12V), indicates its stored energy not power. If you need 7A for 1 hour you need to read the fine print, to see if that was the capacity at its "1C" rate (1x its capacity, or drain it in an hour) Oh wait, there is no fine print on that page, ...

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Yes you understood it correctly, a 12V,7Ah batteries is supposed to provide 7A @12V during one hour. Regarding regarding consumption in Watts, it is the current multiplied by the voltage the device is supposed to run on. If your 60 watt bulb is supposed to work on 250V it will draw 0.24A when powered that way. That's the basic theory. There are some ...

3

For measuring remaining capacity of a LiPo battery pack, search for Battery Fuel Gauge ICs. For instance, the Texas Instruments bq34z100 Wide Range Fuel Gauge supports LiFePo4 batteries from single cell through to 18 cells (3V to 65 V range), monitors battery health, charge and discharge, battery aging and self-discharge. It interfaces using I2C 2-wire, and ...

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I would buy just the PCB. You can get a new and good quality Protective PCB cheaper that you can get a very low end, such as UltraFire, batter with a PCB and you will know it is new. UltraFire is known for reusing old cells so I could see them using old PCBs too. Be sure to check the requirements of the cell and match them with the values of the PCB. Over ...

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Why not use a Lead-Acid battery? Advantages include: Suitable for long-term trickle charging or float charging. Cheap. 12 V nominal. Charging is dead simple - apply ~13.4 V indefinitely. Those guys are designed to be used for backup power supply.

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The packaging: Shows the product type "Alkaline" in small print twice ("alcalines") and the product "Battery" in large print twice ("Piles"). The second form is in French, making the product bi-lingual for less expensive multi-regional marketing.

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"Pile" is the French term for "Battery". You'll see "Pile Alcaline" on most batteries these days; It simply means Alkaline Battery in French. I'm currently looking at a Duracell with it.

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If you directly connect the two, it may quickly age (possibly destroy) your led/lamp, and draw slightly more current from your battery than was intended by the light source's designer. The specs you gave are so unusual, that it must either be a lamp or a led with an integrated current-limiting resistor for 6V. To use it, the easiest option is to add another ...

2

I don't think the part linked is an LED, but it does specify 6V @ 25mA nominal. Looking at some rough 9V battery capacities, let's say the battery has about 565 mAh. Suppose we designed some smart circuitry which magically converted the 9V to 6V and was 100% efficient. The power draw is then 6V*0.025A = 0.15W. Assuming the battery is at 9V until it dies, ...

3

The 6-Volt Minature Lamp you've linked from Radio Shack isn't a LED, it's a small incandescent light bulb. It lists the current draw as 25mA and a 9V PP3 alkaline battery normally has a capacity of around 500mAh so I'd expect it to last around 500 / 25 = 20 hours. It will be less for cheaper zinc carbon batteries. The other issue is that it's a 6V bulb so ...

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I do not find figures indicating the voltages as measured in full charge state and also whether the charger contained auto cut off when fully charged. NiCd and Ni Mh cells have memory that makes them to charge and discharge at an accustomed pattern. If the battery is found draining out fast without reference to tis fully charged condition, they are ...

1

If you have 100 LEDs in series you're looking at about 160V DC to drive them. Or 240V for green or nearly 400V for blue or white. Separate them into smaller strings. If they are different colours, adjust the number in each string to give a convenient drive voltage - e.g. 10 red LEDs and 2V across the current limit resistor will work reasonably well off ...

3

If you want to power all of the LEDs in series, you only need a single current-limiting resistor for the entire string. However, your power supply voltage must be at least the sum of all of the LEDs' forward voltages. If that's not convenient for your application, you should divide them up into separate strings and connect the strings in parallel. ...

3

I found that it's possile to go from 1.2v to 5v with the TPS61200 and go from 50mA to 500mA with the L272 but what if they're used together ? Will it preserve my battery lifespan? Let's just say the answer is "yes". Say you had a 1.2V battery which can now provide 5V, and where it could provide 50mA, it could now provide 500mA, with no reduction in ...

4

Consider conservation of energy. Very roughly, 1.2 V * 50 mAh is about 215 J. 5 V * 500 mA is .25 W. At a .25 W rate of use, 215 J will be consumed in about 450 seconds, or 7.5 minutes. Edit Let's look at the chips you mention. TPS61200 is a boost converter. It will "boost" the power supply voltage from 1.2 V to some higher voltage --- 5 V in your ...

1

With that small panel the batteries will not over charge. Check the current draw to the panel in the dark from the batteries to see if you need a diode.

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The batteries can handle a high current load for less than a second even a dead short. If the battery is only a 2AH battery nothing will happen other than shorten the life of the battery. This is ok as long as the motor starts turning and current drops to no more than twice the AH rating of the battery, for a lead acid battery, the surge current is higher ...

2

What you want is called a generator. It is the reverse of a motor. You turn the generator shaft and it produces electrical power. The more tricky part is matching the power out of the generator to what will charge the battery without damaging it. That's a much longer discussion with lots of tradeoffs. At your apparent level, get a big enough and robust ...

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I can't tell you what the problem is with your apparatus since the photos can only give a limited amount of information. However, it appears from the photo that you just have a voltage source (battery) in series with a resistor in series with an ammeter (you do have the multimeter set up to measure current and the leads connected to the proper inputs, ...

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Here's the item you linked: - It's a 12V output capable of supplying up to 25 A - is this enough for your appliances You can power it from 36 V to 75 V - is this OK for your set-up - Any unforeseen voltage spikes that might mean you need to consider over-voltage protection feeding the supply to it? Efficiency of 94.5% means probably 90% if you read the ...

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To answer your last, and most important, question: the voltage across each cell needs to be kept within the correct range. The batteries will not be physically identical, and so different voltages will appear across each battery in the series chain. With lithium batteries, this will likely result in fire and/or explosions. Proper battery chargers have means ...

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