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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38 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
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0answers
21 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
372 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 ...
0
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2answers
74 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?
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0answers
48 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 ...
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2answers
32 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 ...
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1answer
62 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
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1answer
51 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 ...
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3answers
97 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 ...
0
votes
1answer
37 views

Getting Proper Charger For My Lithium Ion Batteries [closed]

I found an old laptop battery and I decided to take batteries from it. I found 8 Lithium ion batteries.I don't know what would be ideal charger for it. I have one charger, output is 4.8v 0.9A. Is ...
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1answer
44 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 ...
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0answers
21 views

Controlling ESC with Arduino [migrated]

I want to control these motors: hexTronik DT750 Brushless Outrunner 750kv with this battery: Turnigy 2200mAh 3S 25C Lipo Pack and these ESCs: TURNIGY Plush 18amp Speed Controller. I am new to this ...
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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
40 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 ...
0
votes
1answer
85 views

What battery to choose with motors?

I am trying to figure out how many batteries I will need, in order to power my 4-wheeled robot (based on an Arduino). I understand that it is not practical to power the Arduino and the wheels with ...
0
votes
1answer
53 views

Charge condition of lead acid battery

I need to monitor the charge condition of an 8V lead acid battery. For monitoring purposes, I used a Beagle Bone Black running Linux. It is also supplied via this battery. The battery also supplies ...
0
votes
1answer
54 views

Short-circuit xPyS LiFePO4 batteries

I have a LiFePO4 battery connected in 2P4S configuration. What happen if one of the batteries is short-circuited? The other batteries will also be short circuits, or this will be result in the venting ...
13
votes
1answer
427 views

Battery (Li-SOCl) voltage varying with orientation

We are using this 3.6V Lithium battery (ER14505) to power the micro controller circuit in one of our devices. The device is capable of reporting the battery level. Since the controllers brown-out ...
0
votes
1answer
60 views

LiPo protection circuit IC

I'm making a power board for my robot and I am looking for some advice regarding LiPo battery protection ICs. I might need to draw a fair bit of current (9A), though if I get the programming right, ...
0
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0answers
29 views

How to use Mifare RC522 RFID card reader without mains power?

I want to make a simple home security system. I'd like to be able to have an RFID card reader near my door. All members of the family will swipe in and out, and when everyone is out, the web cams will ...
0
votes
1answer
96 views

Connecting batteries in parallel (concerns)

I have been trying to understand if it is possible to connect two identical batteries in parallel (same: number of cells, manufacturer, capacity, CRate, usage). I want to create a circuit to select ...
0
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0answers
36 views

Difference in self discharge rate between Lithium iron phosphate battery vs Lithium Polymer Battery

What is the difference in self discharge rate between lithium iron phosphate battery and lithium polymer battery? I have a remote application in which the self discharge rate matters a lot.
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2answers
66 views

Shape Memory Metal framed sail

I am working on a costume prop that utilizes a triangular cut sheet of emergency blanket spined with a single 12" long, .04" dia piece of nitinol wire that has a transistion temp of 115deg F. My plan ...
1
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1answer
36 views

Difference between Lithium Polymer batteries of varying capacity and cell amount

I was looking to purchase a LiPo batteries online for a side project. Upon shopping around, and reading up on LiPo batteries, I have a fair understanding on what the numbers/letters on the battery ...
1
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0answers
58 views

AGM Batteries: Comparison of Auto to Marine

Research (links go through to the actual product descriptions, for those who read specs): Diehard AGM Auto Group 34 775 CCA: $153 Diehard AGM "Marine" Group 34 880 CCA: $250 West Marine house brand ...
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2answers
82 views

Low noise voltage regulation

I have a circuit which currently runs off of either a 12VDC wall wart adapter, or it falls back to a 9V battery if the wall wart adapter is not connected. My circuit currently uses a chip which ...
0
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3answers
75 views

Low battery level circuit - Changing “trigger” level

I am re-creating a simple low-battery level circuit that turns on a low-power LED to indicate that the battery needs to be changed. The circuit is shown below. There are two things I would like to ...
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0answers
55 views

Which would be the safest battery type for a wearable electronics?

Which battery chemistry is most suitable for a wearable electronic gadget like a wrist band? I wanted to consider safety, and potential power (mAh etc)? I know there are the new "flexable" batteries, ...
3
votes
3answers
442 views

Automatically switching from 9V battery to DC wall adapter on insertion

I have a simple circuit that runs off of a 9V battery. I'm re-designing it so that it can also run off of an external 12V DC source (ie: a wall adapter). I want to design the circuit so that if both ...
1
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0answers
36 views

Li-SoCl2 battery state of charge

I'm developing a data logger powered by Li-SoCl2 (http://www.100y.com.tw/pdf_file/02-SAFT-LS33600.pdf) battery and I have no idea on how to overcome the problem of estimating the residual charge of ...
1
vote
1answer
57 views

How big should battery be to power two strips of led for few hours?

I have an idea for halloween costume for upcoming Halloween. It will involve building two small sets of infinity mirrors. I am completely new to the electrical engineering. The infinity mirrors ...
4
votes
2answers
355 views

What is a safe max. discharge rate for a 12V lead acid battery?

I've got a 12V 2.4Ah lead acid battery which I plan to connect a water pump to. I've looked at various pumps, but the one I'm most interested in draws 2.2A. I'm not so interested in how long the ...
2
votes
2answers
107 views

Battery Charging Circuit - NiCd

I am designing a battery charging circuit for an in circuit NiCd battery (used on a RC car). From my research I understand that I need to charge using a constant current source, and for fast charging ...
11
votes
2answers
851 views

Why don't we get shocked when we touch a car?

According to this answer to a question about car batteries: [...] so the entire chassis is an extension of the minus terminal of the battery. If this is the case, I would expect that you'd get ...
1
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1answer
47 views

How to charge an iPad for maximum battery efficiency [closed]

iPhone chargers provide 5W of energy while iPad chargers provide 10W of energy. If you plug an iPad in an iPhone charger it will charge slower than normal. Also, there are many computers which provide ...
0
votes
3answers
67 views

Figuring resistor wattage and value

I have a remote controlled airplane that I am putting LED lights on. The power supply is a lithium polymer battery that is rated at 22.2 volts and 4000 miliamps. I have an LED that is rated between ...
-2
votes
2answers
104 views

Where does power in my laptop go when I disconnect the battery? [closed]

I have a laptop which, when put to sleep, sometimes enters a state of limbo, from which it can be neither turned off nor on, and the only solution is to disconnect the battery, reattach it, and turn ...
0
votes
3answers
92 views

How long would an original gameboy last on a modern lithium battery? [closed]

The original Gameboy was famous for it's battery life on 4AA batteries. My HTC One smartphone can last about as long as the GB did back in the 80s. So how long would an original gameboy last if ...
0
votes
1answer
60 views

LiFePo4 2 Cell Series Charging with MCP73223

I want to make a charger for two LiFePo4 cells in series. As I'm aware, charging cells in series may be problematic, due to slight differences on each cells, that may charge one and not the other, ...
0
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1answer
98 views

Is it okay to put a solar cell and battery into resin?

I was thinking about making a simple circuit with LED, solar cell and battery and put it in resin mold to make it weather proof. I wonder is there anything wrong (chemically) with putting a battery ...
1
vote
3answers
132 views

Are control systems and motors typically driven from the same source in robotics projects?

My control system is a simple microcontroller between 3.3V and 5V, but the stepper motors I require are 12V. I have ordered a 14.8V battery that I intend on regulating down to 12V to drive the motors, ...
1
vote
1answer
48 views

Flash Bulb battery depletion

Extremely simple question for you. Probably beneath all of you to answer apologies for that. My camera's flash is rated in Watt seconds. My battery is rated in mAh . If my battery can output 1000 ...
4
votes
2answers
148 views

What are the use of these diodes?

I have a circuit diagram which is for a circuit used for testing batteries under a load, only one of the batteries can be tested at a time and I was just wondering what the point of the diodes in the ...
0
votes
1answer
69 views

NiMH battery charger using discrete elements

Below is a schematic of NiMh battery charger that must automatically switch off charging current when battery is fully charged. I am aware that the main part of this scheme is current source, build ...
0
votes
2answers
78 views

Looking for efficient battery supply to power 3.3V circuit

I have been searching everywhere for the best way to power my circuit and I can't find straight forward information. My circuit needs 3.3V and the maximum current it draws is 50mA. It will run at ...
-1
votes
2answers
71 views

Issue charging a 12V battery using solar charger

I bought a 12V solar charger for vehicle batteries, because I am usually using wall chargers and I wanted to give green technology a try. When I connect the solar charger to my battery, it shows 10V, ...
3
votes
1answer
65 views

What can be the consequences of charging a lead-acid battery with an excessive voltage?

In my field-operating device I use a simple PWM step-down to charge a 6V 3.9Ah lead-acid battery from a 5W solar cell with a voltage of 7.2V. Unfortunately the DC regulator got damaged today and the ...
1
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2answers
47 views

nexus 7 battery repurposing [closed]

I have just broken my nexus 7 and I was about to salvage the battery. I was thinking of using it maybe to power my raspi or arduino. My main question is how do I charge it? I was thinking of cutting ...
0
votes
2answers
73 views

Can my 3.2V LiFePo4 battery power my cell phone through the cell phone's micro USB port? [closed]

I have a large LiFePo4 battery cell made by Headway (model 40152S 15AH single CELL, 3.2v). I'd like to use it to power my Samsung Galaxy S3 phone. On the original phone battery it says that it is a ...
0
votes
1answer
59 views

Power supply for Raspberry Pi

Before you tell me that the question has already been asked, only similar things have been asked. I need to power a Raspberry Pi with some electrical equipment attached to it. The Pi needs to run ...