Tagged Questions

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

learn more… | top users | synonyms (1)

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1answer
34 views

Power a laptop LED backlight with NiMH batteries

I'm powering a laptop LED backlight with an external 24,8V power supply, because I have problems with the internal WLED driver. The display used to work at 27V, but with the 24,8V of the power supply ...
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0answers
24 views

Can I run a 3s ESC from a 12V power supply (car battery)?

I am building an ROV, and my thrusters will require 12V. The voltage source will be a 12V car battery. I have found this ESC and it seems to be just what I need (well over my ~9A draw and has ...
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0answers
58 views

Relay between battery and chassis [on hold]

Although the battery is already connected to the chasis of vehicle directly by cable, there is a small gauge cable connetion to the chassis with a relay between the two. What is the function of this ...
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0answers
43 views

Problems using 12V SLA batteries [on hold]

I have used two SLA batteries. They were charged by Two Diode Full Wave Rectifier circuit. Although I have two 12 volt batteries, each showing 12.56 volts, they are not able to run a BLDC motor of ...
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3answers
84 views

Best kind of battery for electric motorcycle?

Sorry if this question doesnt belong here, I am new and learning. I want to try and build a DIY electric motorcycle, but am having issues finding the right batteries to use. I've tried searching for ...
2
votes
1answer
68 views

Making my own waterproof battery pack?

Today I had a bad experience on my cycle commute home from work - my battery pack died and I was left without a front light for 20 miles of my journey home. So I want to see about creating a new, ...
0
votes
1answer
69 views

Arduino standalone with 9V battery and accelerometer

I'm using an Arduino Mega for a project involving an accelerometer. Everything works fine when the board is connected via USB. When I use a 9V battery plugged in with the 2.1mm jack, values are ...
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0answers
15 views

I am using LiNi0.6Co0.2Mn0.2O2 as cathode material for Lithium-ion battery, but I [on hold]

I am using LiNi0.6Co0.2Mn0.2O2 as cathode material for Lithium-ion battery, but I don't know what's the density(g/cm3) of this material? And what's the disadvantages and advantages of it? May you help ...
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2answers
57 views

About battery capacity and regulation

For a portable application, I would be using a single 3.7V 2600mAh li-ion cell. The circuit requires 2.5V to 5V to function with the current requirement being 100mA. So obviously a voltage regulator ...
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2answers
89 views

Purposely draining a battery by a resistor

I'm new to electronics and wiring, and wonder if a 15 ohm resistor will drain a 1.5v battery (specifically a Duracell Alkaline AA) in a reasonable amount of time to a super-intense white LED. Does ...
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0answers
51 views

How long will my ~20W device last with a 18000mAh battery?

I have a Mac Mini with a max power consumption of 85W but an average power consumption of ~20W (in my experience). I'm thinking of buying a portable power source with a 18000mAh battery. How do I ...
0
votes
1answer
65 views

Turn Laptop Battery to a Power Bank

Is it possible to turn a laptop battery into a power bank? I have seen video tutorials and articles on how to turn AA Batteries into power banks, however, no one has created a power bank using a ...
0
votes
1answer
53 views

Line-of-Sight method of simple code transmitting for outdoors

I'm trying to determine the best way to do this. Basically I'm trying to design a system that would transmit a signal containing a simple code to allow the receiver to identify the source device. It ...
0
votes
3answers
79 views

fast battery drain

I have a 11.1V li po battery (3S). I wanted to drain it fast so I could test a charger circuitry. How can I do that fast. Unfortunately,I do not have high current consuming loads which can drain a ...
1
vote
2answers
159 views

What type of batteries are these?

So, I can get these batteries very cheap - less than $2 a piece. However, I have no real idea how to use them. (I intend to power a robot with them if I can.) So this begs the question: what kind ...
0
votes
1answer
59 views

Can I connect directly a 3.7V 18650 li-ion battery to a mobile (cellphone)? [closed]

If I remove the 3.7V battery from my mobile, is it possible to connect to the battery +/- terminals a 3.7V li-ion 18650 battery?
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votes
3answers
110 views

Calculating current draw from a battery using voltage and time information

Is it possible to work out the current or power a device is drawing/using, based on the following information: Maximum capacity of a battery (48 Ah) A table of voltage readings over time (starting ...
0
votes
1answer
67 views

Understanding Battery rating

I need clarification regarding the rating of the battery shown in the below figure. I know battery ratings are given in Ah(Ampere-hour), but here it is given A/s. The picture is from "Linden's ...
0
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0answers
28 views

Please help determining component specs of BQ76930 (BMS IC)

I was wondering if you guys could help me with some questions I have about the BQ76930 schematic (below, also found here: http://www.ti.com/product/bq76930 on page 42). How can I determine what ...
0
votes
2answers
45 views

Which is the best rechargeable 9v battery with high capacity? [closed]

I was looking for rechargeable 9v batteries with high capacity? I found "Energizer Ultimate Lithium - Battery 9V Li 1200mAh" on that site bellow. ...
0
votes
1answer
60 views

Recharging a Lead Acid battery

I've an old lead acid battery with the following specs: 12V, 7.2Ah Valve regulated Sealed lead-acid type I've no idea about batteries prior. This battery has been in the attic so far and I would ...
0
votes
0answers
10 views

Alakaline Battery Chemistry [migrated]

I'd like to understand the chemical reaction in a typical Alkaline battery a little better and how that produces a flow of electrons. I read wiki, how stuff works, and some more advanced articles. ...
1
vote
1answer
62 views

Are there any high energy density (i.e. zinc-air or lithium-manganese dioxide) batteries without high internal resistance?

For my wild life camera, I want a small cell that can provide 0.5W for 8 hours or more. It doesn't seems rechargeable lithium ion batteries have that energy density. I don't mind if the cell is ...
1
vote
1answer
72 views

Switching between USB power and single alkaline battery

I've read the numerous other questions addressing this topic, but I'm not sure if any of them apply to my situation. I am designing a device that will run off a 3.0-3.3V supply voltage and draw no ...
1
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2answers
56 views

Why are different currents used for charging batteries with the same voltage output?

I'm trying to understand the behavior of batteries a bit more. I've noticed that chargers for given batteries have different current capabilities. Do batteries need to be charged with a voltage that ...
0
votes
3answers
77 views

creating mp3 device playing sound in specific time [closed]

I need help with creating device that will be able to play sound (can be recorded or from mp3/wav...) at certain time, for example at 8:00PM, 8:15PM; 8:30PM ...until 5:00AM. Device must be powered ...
2
votes
1answer
56 views

Bi-directional High-side NFET switches — drains or sources connected together?

TL;DR: When using two N-FETs to implement a high-side switch should the FETs be arranged so the drains are connected together, or the sources? Some additional facts about the current design: 1) A ...
1
vote
3answers
144 views

May I power atmega32a-pu microcontroller from AA batteries?

I need to provide +-4.5V to the microcontroller. That would be fine by having 4x rechargable batteries, but how is it with current? On each AA battery is written min.2550mAh. I am not sure but I think ...
0
votes
0answers
47 views

monostable 555 current is bleeding, battery dies

This is likely an obvious question to an electrical expert, but I am only doing my best. My monostable 555 project is currently working: when triggered, an LED gets 5V and stays on for 5 minutes. ...
0
votes
3answers
92 views

Can I just connect two CR2032 batteries in parallel?

I'm designing a device with a small current draw that will mostly sleep in a very low power mode and I need to use button cell batteries due to a limited thickness. I would like to double time between ...
2
votes
2answers
245 views

Li-ion Battery - Constant Charge

I have system that 98% of the time consumes less than 300mA. The remaining 2% it consumes 550mA. It is a USB system and works with a PC. I have looked at various options to stay withing the 450mA ...
0
votes
2answers
70 views

voltage drop when using voltmeter

it's a theoretical question. is there any voltage drop when measuring a 12v battery with a multimeter(voltmeter mode)? so if we get 12 Volts reading near the battery, does this changes if we extends ...
0
votes
1answer
48 views

Running a load off a solar panel connected to 2x 12V batteries.

I am having trouble figuring out what relay I should be using for my solar panel set up. I have a solar panel running to a solar charge controller. I then have the controller running into a relay. ...
0
votes
1answer
48 views

Effects of C Rating on Battery Life

A polymer lithium ion battery is rated at 3.7v, 6600mAh and a maximum discharge current is specified at 3.3A. I take it this means the battery can be discharged at 3.3A and last for two hours since ...
0
votes
1answer
45 views

Battery dimensioning

For a school project I'd like to put a "fit pc 2" (a RaspberryPi-like) on a flying device. As the fit PC2 is supposed to be directly plugged to energy, I'd like to buy a battery to let it work in ...
1
vote
2answers
79 views

Replace 12V 5A power supply with battery

I am buying a rgb led strip with the following technical details: Voltage: 12 volts Wattage: 60 watts I want to connect this strip to a battery and don't know ...
1
vote
3answers
182 views

Direction of current through a circuit with multiple batteries

So I've got a bit of a problem trying to understand this circuit in my physics book. If current flows in the direction of the three arrows (I1, I2 and I3, couldn't find a way to name them) how can ...
0
votes
1answer
112 views

9v battery to parallel 3v LEDs - burnout

I'm having an issue in a simple (n00b) LED circuite - ended up burning out a couple of LEDs due to some mistake I'm making, but can't figure out what the error is. I've got a 9v battery, trying to ...
0
votes
2answers
57 views

Measuring internal resistance of a battery while it's being charged

I was startled to hear that there are devices out there that can measure the internal resistance of batteries, in circuit, while the batteries are being (trickle-)charged. For example, Hioki markets ...
1
vote
1answer
49 views

Why are the charge and discharge rate of Lihium Polymer Batteries different?

I have a 3S 1.3MAH Lithium Polymer battery with a 25C discharge rate, and a 5C charge rate.From what i know, the discharge rate is the rate at which the battery can be safely ischarged( i.e how many ...
5
votes
3answers
439 views

What should I use for powering a Raspberry Pi at near space altitudes?

I'm planning a high-altitude weather balloon project (to around 100000 feet) some time down the line to take video and pictures of near space altitudes and I have some questions I need to ask before ...
1
vote
2answers
93 views

How much current does a typical multimeter draw to measure resistance?

Assuming it's running on a 9V battery like most multimeters are, and the setting is on MegaOhms. How much current will be drawn from the internal battery?
0
votes
0answers
56 views

Is it plausible for this battery to charge 32% this quickly?

So my phone ran out of charge earlier. I stuck it on charge and turned it on. 5 minutes later I came back to it and the screen said that the battery was 32% charged, which seemed a bit odd to me. So ...
0
votes
2answers
72 views

Low voltage cut out switching for a 6v input SLA to 5v output circuitry - or alternative ideas

I am currently modifying a wireless video door phone system with remote door release system, for use with a walking frame, for my elderly mother in-law, who lives alone. The 7"monitor runs a 5v 1a DC ...
-1
votes
1answer
91 views

Charger light circuit [duplicate]

I have a charger light. It gets charged by 220V AC supply. It can light 5 LEDs. I know that it needs to make the supply 220V AC to DC of lower voltage nearly 5V to 10V. Then it can charge the small ...
0
votes
1answer
56 views

Relation between C-rate and power of a battery

I'm a non-engineer, but I need to understand the function of a battery. I hope you can help me! For example, I have two bulk storages. 5MW (power) 5 MWh (capacity) 5MW/10 MWh So the definition of ...
0
votes
3answers
121 views

When is the AA battery voltage drop?

I have a device which is running on two AA Duracell batteries. The batteries (brand new) together is producing 3.2 volts (1.62 volts individually), which is estimated to run for at least 2 years. The ...
1
vote
1answer
52 views

NI-MH battery monitor design. Any obvious errors?

Let me preface this by saying I'm not that much of an EE expert, this is a "hobby" project, I consider myself as knowing enough to be dangerous. ;) I'd never apply for a full time career as an EE ...
0
votes
0answers
28 views

Adding Battery amps [duplicate]

Can you get more amps out a bank of batteries with different configurations? I know that if you put batteries in series you add their voltage, so you have more electrical pressure. And if you put ...
0
votes
1answer
69 views

Low-power dual-rail ADC

I am building a battery monitoring device and planning on measuring voltage drop across a current shunt, amplifying, and reading into an external (12-bit) ADC chip to get a value of the resolution I ...