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)

1
vote
5answers
91 views

Using a BJT to enhance battery life

I have a little project going on, that involves turning on and off a led strip. The led strip specs : 5M Led SMD 600 Lights LED : 3528 SMD 600 Lights, 5m : 120 LED / m According to this site, it ...
0
votes
1answer
64 views

Charging Li-ion batteries in parallel

I wanted some opinion on my set up here, just to make sure I got the basics right. I have a Li-ion battery charging circuit based on the MCP73113. This is designed to be a single-cell battery ...
0
votes
2answers
57 views

Solar panel system with as minimal reliance on the grid

I am not sure if this is the best place to ask, but I am trying to make a solar panel system which will charge batteries with excess energy and will be connected to the mains (i am going to try the ...
0
votes
2answers
100 views

How to make a conductor positively charged?

I want to get a conductor positively charged for a long time. However, the charge shouldn't be so small so charging by friction is not a solution for me. I've heard if you connect the + end of a ...
0
votes
2answers
69 views

Power supply with 10 VDC and 2mA

I have device need 10 V DC and 2 mA, can I use DC battery? For example, two batteries with 5 V DC and 1000 mAh?
-1
votes
0answers
30 views

using power bank damages mobile battery life? [closed]

I have a BlackBerry Z10. The wall charger that came with the device has rating of 750mA for output. I have purchased a PNY power bank with 2A output. Will this damage the battery?
0
votes
1answer
55 views

How to supply multiple 12V DC 3 amps motors?

I need to supply four DC motors 12V @ 3 amps with a battery pack. I was wondering which characteristics should have an hypothetical battery pack to supply all four motors together. How many volts ...
-1
votes
1answer
38 views

Details of lithium-ion battery terminals [closed]

I want to charge my mobile battery while it is external to the mobile. How should I connect the input charger terminals to the battery. I have available a laptop USB port to act as a charger. I ...
1
vote
2answers
45 views

Calculating discharge time of 12V LED light powered by AA batteries

I just want to check up my assumption on power consumption of six 12V LED lights in parallel connection. So I powered it by 6 AA (E91 energizer) batteries. The LED's ideal forward current is 80 mA ...
20
votes
7answers
2k views

How should I use a multimeter to determine which AA batteries to keep and which to toss?

I have a bag of about 50 non-rechargeable AA batteries (1.5 V) that I have collected over the years. I bought a multimeter recently and would like to know the best way to test these batteries to ...
2
votes
1answer
153 views

Optimizing LED Project

I'm working on a project the will use 20 white 3mm LEDs that I harvested from a 154 LED Christmas light string. I plan to use a 9 volt battery for power. What's the optimal wiring schematic? Series, ...
0
votes
4answers
131 views

Wire for project with 9 volt battery

I'm working on a project that powers 20 LEDs with a 9 volt battery. What gauge of wire should I use? A couple of LEDs are in series with a 180 ohm resistor. Then each pair are in parallel.
0
votes
3answers
82 views

How can I make a safe Ni-MH charging station?

I wanted to make a docking station for my robot. My idea was simple - robot drives in, batteries are disconnected, pins that I attach to my Ni-MH charger's electrodes are inserted into battery pack, ...
-2
votes
1answer
79 views

Battery Current Stabilizing [duplicate]

So, from I can tell from the answers I received to my previous questions, if I want to lower the output current from a battery, I could put a resistor in series with my circuit. But wouldn't that ...
0
votes
4answers
85 views

Is it possible to power AVR micro project with just one coin cell battery?

My current project setup is: ATmega328P micro with 32 LEDS driven by 4 8-bit shift registers. System without LEDs draws 20mA of current continuously. With all LEDs lit at the same time, it draws ...
0
votes
2answers
51 views

PKZ 1023 Battery

Does anyone happen to know the manufacturer's specs for the PKZ-1023 model battery? All I know right now, is that is that it is NI-MH, 9.6V, and 1000mAh. I was hoping to find a chart of discharge ...
0
votes
2answers
142 views

Batteries & Output Current Limiting

I am currently working on a project that uses a 9.8V 1000mAh battery to power a solenoid, and as I understand it (please correct me if I got this wrong.) a battery capable of delivering 1000mAh is ...
1
vote
1answer
225 views

Why my transistor switched when base was grounded?

I am from a programming background, so I dont quite know the theory, But I want to control a motor from a mictrocontroller. So I used a TIP 122 to do it. My circuit looks a bit like this: ...
0
votes
2answers
57 views

UPS battery replacement

For the UPS model Niky 900 by Daker, I'd like to replace the original CSB HR1234W F2 battery with something I can buy on amazon.it, e.g. FIAMM models: could you suggest what are the relevant ...
0
votes
3answers
93 views

Current flow through a battery

So this might be a stupid question and I really should know the answer to it but I am having difficulties with a circuit I have made to drain a battery. The basic idea of this circuit is that I have ...
2
votes
1answer
64 views

Lower Voltage LED organ

I am interested in adapting this Jameco kit schematic to my own needs. I have run into an issue though. I am not sure how to lower the voltage requirements. This circuit is built for 12V, I would like ...
0
votes
3answers
83 views

Current capacity of batteries wired in parallel

I'm wondering what would happen to the mAh when I connect 2 5000mAh batteries in parallel. Would the mAh over all be 10000mAh?! simulate this circuit – Schematic created using CircuitLab
0
votes
0answers
37 views

Rechargable battery solution for Arduino Uno

I am currently working on a project including an NFC Shield and a Bluetooth Shield intend on making the project wireless. My question is; Are there any battery solutions that allow me to ...
-2
votes
2answers
94 views

How to connect 3 toggle switches to 1 battery supply, using 1 wire

I currently have a battery supply, 3 toggle switches, and a Protoboard. The protoboard has various components connected to it, incluing two motors. I need to connect two switches to the motor pins, ...
0
votes
4answers
237 views

Powering an ATmega328 chip

I am trying to make a printed circuit board for a robot. I would like to make this look as neat as possible, and I would like to have the peripherals like the sensors and other stuff, and the ...
0
votes
1answer
53 views

electrical fridge running on car battery [closed]

I'll be out of grid for some days and I'm planning to have a small electrical fridge with me. It's a 12V 4A small fridge with a cigar lighter plug, but I won't have a car with me, so I think I could ...
1
vote
1answer
59 views

What Lithium chemistry in phones' (now) 3.8V batteries?

I'm specifically looking for the discharge tolerances...can communicate with the charge controller on the phone and want to increase the discharge depth from 3.5V to say 3.1-3V for longer battery ...
2
votes
4answers
240 views

Is there a clever way to prevent a window comparator from oscillating?

Here is my schematic It's basically a crude battery level detector (I am very aware that this isn't the best way to guage battery life, I'm not here for that) it's not crucial that it is super ...
0
votes
2answers
63 views

How long will it take to completely run out of power a Li-ion battery of 3.7V and 1000mAh, if the load consumes 16mA?

I'm trying to determine the exact time that run out power a Li-ion battery of 3.7V and 1000mAh. I'm using a load of 16mA. If I use the theoretical calculus: $$time=\frac{1000mAh}{16mA} = 62.5 ...
0
votes
4answers
78 views

Batteries with same voltage but different number of plates

Why do some batteries have the same voltage with a different amount of plates? What is the specific purpose of that? E.g. 12 V with 11 plates and 12 V with 13 plates.
0
votes
2answers
62 views

Panasonic Eneloop BK-3MCC (4th gen) - where I can find maximum discharge current?

Im looking for some official information source about maximum current for Panasonic Eneloop BK-3MCC rechargeable batteries. All I found is single page data sheet, there is just 1 table (nothing about ...
3
votes
0answers
80 views

Lithium battery consuming more power on Sleep Mode

I am trying to reduce the power consumption for PIC18F87J11 on sleep mode. The PIC is drawing about .01 mA (6 uA) on sleep mode with Alkaline AAA batteries and other power source, but when I use ...
1
vote
4answers
241 views

Why does TTL work with 5V, when there's no 5V battery?

It's a noob question, but every circuit I make uses 5V: 74LS uses 5V, ATMEGA328 uses 5V and so on. But in reality, everybody's designing circuits and shove a voltage regulator with 9V or 12V power ...
2
votes
3answers
92 views

How do I keep my constant current source constant?

So I am trying to created a current source that will be used to drain a battery at specific time intervals for a specified duration. simulate this circuit – Schematic created using ...
2
votes
1answer
51 views

How to keep rarely-used Li-Ion batteries functional?

I have many gadgets around the house that I don't use often, recently I notice that a battery failed on an Mp3 player not used for a year. The battery now has a life of 1 minute from the original 5-7 ...
2
votes
1answer
123 views

Charging 10 1.2V nicd batteries

I have 10 x 1.2V Sanyo NiCd batteries. They are connected in series. I would like to charge them. The thing is, I don't have a charger. I looked up chargers and they are all quite expensive(I live in ...
1
vote
2answers
65 views

Battery Polarity

I was bored at work, and remember when i was little, putting batteries in the wrong way would stop the object from functioning, then decided to try reversing the polarity of the batteries in my torch, ...
0
votes
0answers
51 views

Which type of power supply to equalize SLA battery?

I have some 6V SLA batteries wired in parallel and am wanting to apply a 7.5V (2.5V * 3 cells) equalization charge for a couple of hours. The problem is I'm trying to figure out which type of power ...
0
votes
1answer
70 views

What size/kind of diode to use for a lawn tractor charging circuit [closed]

I have a lawn tractor which is not charging properly. I only see 25-28 V AC out of the engine to charge the battery. I can't seem to locate where the diode or rectifier is. When this fails, is it ...
5
votes
1answer
109 views

How power system is designed for extreme small system, such as google contact lens?

I just read this news and got very curious: http://www.takepart.com/article/2014/07/23/goodbye-finger-pricking-how-googles-smart-contact-lens-really-helps-diabetics Google is designing "Google ...
0
votes
2answers
111 views

How to calculate battery life with a given load?

I am not very good at electricity things so any help anyone could give me would be fantastic. Here goes: I have a battery (for power tools); it is 18v and 1500 mAh (imagine DC). I'm trying to get it ...
4
votes
2answers
324 views

Battery Ampere-hour rating vs Battery Amps (not an experienced user)

I have almost no experience whatsoever with the technical's of electronics so this is probably a very easy question for someone who does... Do you know if a battery with a 200Ah rating can put out ...
-1
votes
2answers
84 views

Converting a 9v Battery powered Device to a 9v dc power supply [duplicate]

I have an old Vivanco MX300 mixer which runs of a 9v battery. I have it in the same place and it's an inconvenience having it run by batteries. Could I use an old AC/DC adapter that would supply 9v ...
2
votes
1answer
134 views

Measuring Remaining Battery Life

I am working on a project testing alkaline batteries and need a way to quickly measure remaining battery life. I would like to be able to estimate mA-h remaining in the battery. If I measure mA-h over ...
0
votes
1answer
69 views

Good volts and amps but phone still charging slowly

I am really new to the EE game and am still tinkering. I have built my own portable DC power source similar to a Minty Boost from scratch and plugged it into the USB port of my Galaxy S3 and it ...
0
votes
1answer
67 views

Charge/Discharge efficiency rate of a lead-acid battery

What is charge/discharge efficiency rate of a lead-acid battery and how can I calculate it? Lateral question: Is there any relations between lead-acid battery efficiency calculated via dissipated ...
0
votes
1answer
66 views

Isolating polarities on a series wired battery bank

Can anyone, with 100% certainty (that means you know what you are talking about) tell me how to "isolate" the positive from the negative posts electrically in one direction so I have a true 'positive' ...
0
votes
1answer
44 views

Lengthen charge times with batteries

Would replacing a 3.7v 1000mAh lithium ion battery with a 3.7v 5000mAh lithium ion batter make my projects last longer between charges?
1
vote
2answers
82 views

How to power my datalogger?

I am building GPS datalogger. It will consist of Arduino Pro Mini 3.3V, GPS module - GY-GPS6MV2 (GPS Ublox NEO-6M) (bypassing 3.3V regulator) or Skylab SKM53 (MT3329). Data will be written to SPI ...
2
votes
2answers
133 views

Do cell phone batteries contain protection circuits?

I have tens of old cell phone batteries lying around and I want to try to make use of them. I've googled around for the answer, but haven't able to come across anything consistent. LiPo batteries ...