An electric battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy

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0answers
43 views

Why Battery Life Differs so Dramatically on Watches? [duplicate]

Trying to rephrase this question How Can A Cheap Watch Battery Last for 13 Years? with more details. Bought this watch 13 years ago, the battery is still going strong. However, batteries on several ...
0
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2answers
31 views

battery overdischage oscillation protection

I previously asked asked an advice on power control of battery operated system. The problem was to cutoff the battery when low to avoid overdisharge. I have built the device according to Olin ...
0
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0answers
67 views

How Can A Cheap Watch Battery Last for 13 Years? [duplicate]

I bought this cheap watch from Walmart for $12 in summer 2002, never changed battery but it's still going strong, not even low battery warning. How is this possible?
0
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0answers
34 views

How to shield an isolated battery powered system?

I'm currently in the process of "designing" (selecting) a DC-DC Converter solution for a battery powered widget that will operate in the desert. It has to comply with various aspects of ...
-4
votes
1answer
32 views

Choosing the right battery for a bluetooth product [on hold]

I'm making a autonomous low power device. The device is a Bluetooth module working as an iBeacon (low power mode) that waits for a external connection. It's durability without charging must be 2-3 ...
0
votes
0answers
36 views

Single IC solution: Li-Poly / Solar charge and management [on hold]

I'm making a discrete device which will manage a room light (up to 2A LED) from solar cells and which will switch to battery once solar cell voltage drops below 10V. An op-amp with hysteresis used as ...
5
votes
2answers
252 views

Logging lithium battery discharge: why this curve?

I'm using Arduino to log the discharge curve of a 5V battery pack (usb type for smartphone recharging). Using Arduino I read the voltage every second and I save it to a log file. Arduino is powered ...
0
votes
1answer
38 views

Should I take off my pc batterie when pluged? [on hold]

I'm totally new to the site. I hope you wil accept my question. I have a Samsung rv420 laptop, with windows 7. It has a battery, and the battery works normal (probably less time that when i bought it) ...
1
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1answer
94 views

How long can I draw 5 Amps from AAAA batery

So this question might sound a bit weird, but if I had 14 rechargeable AAAA Battery strung together in series so the total voltage out put is 16.8 Volts, how long could I draw 5 Amps from the ...
0
votes
1answer
29 views

Lithium vs AGM vs Nickel Cadmium (pocket plate) batteries [on hold]

I am looking to use a 100-200ah battery for my inverter. There will be a charge and discharge cycle everyday. So in terms of safety, life cycles, cost, rugged usage, rapid charging and discharging, ...
4
votes
3answers
533 views

Regulating AA to 5V and achieving high efficiency

I'm trying to regulate a single AA battery to 5V for charging a USB device. I know even at perfect efficiency, it won't provide much juice (1.5v * 1500 / 5v). But what is the expected efficiency for ...
-1
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0answers
17 views

SMS sending /receiving Power Consumption? [on hold]

I am very new in this forum as well as in my research. I need to know " how much energy consumes an SMS sending / receiving at 3G and Wi-Fi"? Please let me know how to measure that energy, like if ...
0
votes
2answers
46 views

Simple piezo buzzer circuit--could I power it using a large battery?

I am fairly new to electronics. I was thinking about a simple circuit and was wondering if it would theoretically work or not. Say I wanted to connect a 12V Piezo buzzer to a switch and a large ...
0
votes
3answers
82 views

How does charging a phone battery work?

For example, if a phone comes with a charger rated at 5V and 0.7A, when it's plugged in to charge, what dictates the current the phone draws, is it the resistance of the phone? If I = V/R, do phones ...
0
votes
2answers
61 views

Battery gauge – Microcontroller 3.3V using a 4.8V NiMh battery source

Well I am currently working on building a battery gauge via LED. My target is a red LED to blink if batteries are going to die and a green LED to blink if the batteries are fine. Researching on ...
0
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1answer
44 views

piezo and 3v LED in series to 3v battery

I'm a complete newbie to electronics. This piezo I have works with a 3v battery, and this green 3v LED works with the 3v battery, but when I combine both the piezo and LED in series on the 3V ...
1
vote
1answer
27 views

Charging circuit for a small capacity (13 mAh) li-ion battery

I got my hands on some of Panasonic's new "pin-type" li-ion batteries – the CG-320. However, I have never had to charge a battery with such a low capacity (13 mAh). Are there charge management ICs out ...
0
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0answers
47 views

SLA (Sealed Lead Acid) Battery Float/Trickle Charger Design

I would like to replace an unregulated transformer-based built-in charger in an emergency LED lamp. The biggest problem with the original charger is that when the current tapers off, the voltage ...
-2
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0answers
38 views

Using UPS as portable electricity supply? [closed]

Would a UPS system be usable for portable mains power or would the deep cycling kill it in no time? I'm considering buying a 650VA / 360W UPS to power a 20W device outdoors - roughly how many minutes ...
0
votes
2answers
63 views

what battery(s) do i need to power a 12 amp 200 mph motor for 1 hour?

I have a plug in leaf blower/vacuum and would like to convert it to battery power. here is a link to the equipment in question. ...
0
votes
0answers
30 views

Battery testing depth of discharge vs cycles

I am currently investigating the relationship between the depth of discharge of a lithium battery, the number of cycles and capacity lost. I know from literature that the lower to DOD (%) the more ...
1
vote
1answer
57 views

Adding a remote switch and battery to a 9 volt dispenser

I have an insecticide dispenser in my shop. The unit is designed to spray a short burst of insecticide once every 8 minutes. I have found I don't need this frequent of a burst and my thought is to ...
1
vote
3answers
65 views

Conductive body of flashlight

I have a flashlight that seems to use the inside of the metal body to conduct the negative terminal of the LiPo battery inside. The outside isn't conductive - likely anodized. Would there be adverse ...
5
votes
2answers
499 views

5 year run time on small battery

I am working on a project that checks a sensor every 12 hours and reports the status via cellular modem to our server .. Power consumption is less than 1mA during sleep mode and spikes to 900mA ...
1
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1answer
101 views

Theoretical infinite voltage here! Where's the problem?

Update: Thanks Spehro Pefhany for finding the issue! I've got a formula deduced which should - in theory - suggest that a battery with no external load connected should have an infinite external ...
0
votes
1answer
41 views

Can I secure a 12v battery to my bicycle to charge it? And then attach a 12v horn to it?

I'm from the Netherlands, so first let's clear this misconception up; I mean an actual bike, as in: . Then I want to attach a 12 volt horn to it. I could just put it in the basket. It doesn't ...
1
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2answers
178 views

Difference between battery and capacitor?

Can capacitor acts like power supply, in which situations? How related are charge/discharge time of battery and capacitor? Why battery has longer discharge time compared to capacitor? Why we cannot ...
-1
votes
1answer
62 views

can i use 12v battery while charging? [closed]

hello guys i have 70AH 12V battery and i have triple phase charger can charge from (0 to 140 ah batteries ) the chager turn off automatically when the battery full charge and i have 12V to 220 V ...
0
votes
1answer
46 views

Can I reinsert a partially discharged 12v battery back into a solar battery bank? [closed]

These two questions are close to what I'm asking, but I'd like some specific clarifications: How do we charge a small 12V battery from a large 12V battery bank Increase the capacity of a 12v battery ...
0
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0answers
16 views

What kind of setup and components are in this and how does it work. Also, where can go and find the parts to buy? [duplicate]

This is a sound system I am trying to recreate. It has a 5v fm/bluetooth module on the top of it with a switch to turn on and off.It then runs to a Ceiling speaker with some sort of motherboard in it ...
14
votes
3answers
1k views

Is there any benefit to using a voltage booster (such as Batteriser) on “dead” batteries?

The Batteriser is a crowd-funded product intended to extend battery life by boosting the voltage. It is basically a joule thief that is in a tiny package that slips over the cell. Dave Jones of ...
0
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3answers
143 views

Capacitor size for battery operated device?

I am planning to make a battery operated device. I am using spring contacts for the battery. Since the device will be dropped, I am planning to put in a capacitor. I just don't know what type (ceramic ...
1
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1answer
53 views

LED Poster configuration

I am helping my sister make a LED poster for a concert she is going to. I am using a foam board with some letters she placed on there. I am then going to add LED's on top of the letters to spell them ...
1
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2answers
246 views

Does a 24V inverter consume the same amount of wattage as a 12V inverter?

Let me clarify. I know how series and parallel setups work. I know that in series the voltage adds but the current stays the same. In parallel current adds but voltage doesn't. But that doesn't ...
1
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2answers
88 views

Battery life: 2xAA or 4xAAA - which is better?

Which will provide longer battery life: 2xAA batteries in series or 4xAAA batteries in series regulated to 3V via a voltage regulator or buck converter?
1
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2answers
104 views

Help in the design of a super low power device

I'm building a wireless device that have to last with batteries as long as posible. The device has an rf module with a microncontroller that manages the control, that part is bought and works fine. ...
0
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0answers
23 views

How to verify the Energy and Capacity delivered by the Lithium Ion battery?

How to verify the Energy and Capacity delivered by the Lithium Ion battery? I have a Lithium ion batter with below configuration: Nominal Voltage 4.2 V Nominal capacity 2250 mAh I am calculating ...
2
votes
1answer
41 views

Run a servo Nimh battery vs Alcaline batteries?

I was now about to power a microcontroller (3.3V) and a servo (HS-755 HB) externally via batteries. The target is to have the max. life time. The servo will work with 4.8V or 6v as the max. Torque ...
0
votes
2answers
38 views

LiPo charging in consumer electronics (less than 1C?)

At what (max) rate LiPo batteries in consumer electronics are charged (for example in cell phones). I mean that LiPo-s are dangerous when overcharged, so what is the best charge rate to be absolutely ...
0
votes
2answers
61 views

From a 3.3v Pin do we separate Positive and Negative flow? If so, how?

If we do not separate Positive and Negative flow, what is the flow from a 3.3V connection? A Little more background on why I ask this question and my confusion follows I have been reading simple ...
2
votes
5answers
128 views

Inserting Capacitor into CIrcuit causes LED to fade - Why?

My components are 2x 1.5 V batteries 25V 2200uF capacitor 3v Led copper cables My circuit looks like the following. simulate this circuit – Schematic created using CircuitLab My ...
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votes
1answer
46 views

5 mA DC Isolated Current Sensor

We are trying to measure the presence of ~ 0-5 mA of DC current in an isolated manner (no shunt resistors). Are there any commercially available solutions?
0
votes
3answers
70 views

Why wont my 3volt LED light up with two 1.5volt Batteries?

I have two 1.5 Volt batteries, a Red 3V LED, and some cables. The batteries I have connected in series like +- +- From my studying I believe I should now have 3 ...
0
votes
2answers
111 views

Using a microcontroller+BLE (Bluetooth Low Energy) +Servo with one battery source

I am currently working on a project where I was looking for a microcontroller that is capable of BLE (Bluetooth Low Energy) which determines a servo's position. Using an Arduino the project works well ...
0
votes
1answer
38 views

Solar battery charging, solar IV curve

I am thinking of making a solar battery charger for some NiMH batteries but am a bit confused as to how make sense of a solar panels IV curve in the application of battery charging. 1) For a direct ...
0
votes
1answer
51 views

How to charge a 18650 battery pack with BMS

I am planning to built a batterypack using unprotected 18650 cells (2600mA) to power a DIY boombox with the TA2024 AMP. The pack will initially be 3s2p (expandable to 3s4p using battery holders that ...
0
votes
1answer
89 views

12 Volt Solar Air conditionair

I saw a post on YouTube where somebody was able to make ice with a 90 watt solar panel, two 12 volt batteries, an ice maker (800 watt spikes) and 1000 watt DC-AC inverter. ...
0
votes
1answer
70 views

Running the AC overnight in an EV car [closed]

I've heard we will have EV cars (not hybrids with small combustion engines) that can drive 200 miles between charges soon. I was wondering about the battery cost (in terms of dissipation) if you were ...
0
votes
1answer
43 views

How to measure resistance of resistance of gel electrolyte using multimeter

How can I measure the resistance of a gel electrolyte using a multimeter? I know the formula to measure the conductivity of a gel electrolyte is k = (1/R) * (d/a) where k is the conductivity ...
0
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1answer
96 views

How to modify USB battery pack to function like a UPS?

I bought this USB battery hoping to use it as a uninterruptible power supply for a Raspberry Pi 2. I researched it, and users said it could be charged while also powering devices...just what a UPS ...