Involving or pertaining to a circuit or device that is intended to be operated with cells or batteries (as opposed to mains power, for example).

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4
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3answers
538 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 ...
0
votes
1answer
57 views

3 phase AC motor 220V powered from 12V battery

I need occasionally drive watergate with gear box (e.g. http://www.servomech.com/main/screw-jacks.htm). Because location is far away from 220V I suppose powering from SLA 12V battery charged from ...
0
votes
0answers
20 views

Retrofitting synthesizer with internal uninteruptable power supply?

I have an old Roland synthesiser (MC-909 sampling groovebox) that I would like to retrofit with a backup battery both to avoid loosing work and just so I can take it down the park with some ...
1
vote
3answers
66 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
501 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 ...
0
votes
1answer
21 views

Load regulation and battery charging

With the MCP73871, the load regulation is 0.08%. Does that mean it expects the battery voltage to increase strictly monotonically? That is, if the device consumes 2000mA at 5V (around 3000mA at 3.7V) ...
1
vote
1answer
37 views

Do I need any special equipment to make my circuit run off power from a phone/laptop charger?

Is it safe for one to replace a 5v battery source with a phone charger without installing any other components to prevent power surges or injury to any people in contact with the device? Also, is it ...
-1
votes
0answers
46 views

Guarantee 9V operation with a battery or wall powered device

I have a device I want to provide a constant 9V of voltage to it while both using a 9V battery or while it has 9V DC power supply running into it (with or without battery) whilst seamlessly ...
0
votes
1answer
29 views

LiPo charging module used as backup?

I am running small stm32/gsm module project and would need battery backup in it. Is it possible to use cheap lipo charging module to do exactly that. I would charge my battery through input terminals ...
0
votes
1answer
45 views

Is it possible to calculate capacity of a battery using a resistor

Is it possible to measure the capacity of a battery if the discharge curve of the battery utilizes a resistor as the load? For example, if a 100 ohm resistor is connected to a battery and then the ...
0
votes
0answers
23 views

How to determine load to use in a battery discharge curve

I am making a discharge curve of a battery I am testing. So for the discharge curve, what load should I use? (This was kind of answered here, but it was kind of a guess in that the load is based on ...
0
votes
0answers
39 views

How to find the cut off and maximum voltage rating of a battery

How can I find the cut off voltage of my battery (for discharge) and a maximum voltage (for charging)? Is there an equation to do this, or are these two calculate by making a discharge curve? Thank ...
0
votes
1answer
47 views

How to make a voltage vs amp-hour discharge curve

This is in regard with another question of mine, how do you make a discharge curve with the y-axis of voltage and x-axis of amp - hour?
0
votes
1answer
48 views

How to make a discharge curve

I am trying to make a discharge curve for one of my batteries that I have. All I know about it is that it is a 1.5V battery. Now if I have to make a discharge curve for it, how would I make one and ...
1
vote
2answers
67 views

Boat Auxiliary battery - this simple ok?

I have feared running out of battery voltage to start the boat engine after running the electronics with the engine off. Would something as simple as this figure work? Obviously both are 12V. Main is ...
0
votes
1answer
40 views

I have a solar powered keyboard [closed]

I'm no engineer and am no electronics type person at all. I friend suggested I post my question here. I have a solar powered keyboard that uses an ML2032 3v lithium battery. I ordered a new one and ...
0
votes
0answers
9 views

Question about Solar Panel and Lithium charging board

I have a 6V 4.5W solar panel which I would like to use to charge my Lithium-Ion batteries. The battery chargin board accepts 4.5-5.5V. Would it still be safe to use it with 6V? If not, should I just ...
0
votes
1answer
55 views

3.3V Voltage Regulator for LiPol battery [closed]

I'm looking for a low drop voltage regulator to use in a 600mA – 1000mA (peak) 3.3v system that can be powered either through a singe-cell LiPol battery or USB (so a max drop of ~0.4V). So far the ...
0
votes
0answers
36 views

Powering LCD driver board with li-ion battery pack causes screen to go on and off

I have PCB8000099-V.6 HDMI to LCD board. I am trying to power it using 5V 2A USB li-ion battery pack. When I do so the screen repeatedly goes on and off. What would cause that to happen? I am using ...
0
votes
2answers
35 views

Picking battery for power amplifier

I have bunch of TDA2003 (class AB) amp ICs and I would like to make some amplifiers with them. One would be stationary bridged 20w version and one portable version. However I'am a beginner and I never ...
0
votes
1answer
65 views

Potential safety hazard? [closed]

Suppose one uses a poor 18650 (low quality and without a datasheet) to charge a phone and the phone tries to draw 3A-4A (2A @5V) from it. Would this be hazardous even with a protection circuit built ...
1
vote
2answers
173 views

How come 2 MOSFET chips are needed in protection circuits?

Like those here, the protection boards have at least 2 MOSFET chip (AO8814). Does anyone know why so many (4 fets) are needed?
2
votes
1answer
49 views

Implementing protection circuitry for a single cell [closed]

I'm hoping to embed a protection circuit for a single 18650 in my device's circuit. No over-charge protection is needed since it won't allow charging - so only protection against over-discharge, ...
0
votes
0answers
33 views

How to make a Lithium-Ion battery sub-zero proof

I'm planning to use 2 Lithium-Ion batteries in parallel to power my arduino via a step up converter. The batteries get charged using 5W a solar panel during the day. The problem iy, temperatures can ...
0
votes
2answers
150 views

Can I use a transistor to switch to battery backup power when main power goes out?

I am putting together a circuitry, and I want the circuit to continue running even after main power goes out. So I was thinking about this idea of using a PNP transistor and a one-way diode to ...
0
votes
1answer
23 views

Run LED strip from battery

I'm making some lighting for my safe I have one metre of LED strip it runs on 12volts at 1000mA and A magnetic read switch how can I run them off a battery ? I tried a 9volt battery but it got ...
0
votes
1answer
33 views

Mounting battery terminal contacts in an aluminium case

I'm trying to mount AA terminal contacts in an anodised aluminium case. Given that the aluminium is anodised, does that mean it's not conductive and the contacts could directly make contact with it? ...
2
votes
2answers
208 views

Are the silver terminal caps the only conductive parts on an AA battery?

With AA batteries, are the silver terminals the only conductive parts on an AA battery? That is, is the outpost ring around each terminal (part of the body casing?) conductive? I'm asking because I'm ...
0
votes
2answers
157 views

Is it possible to combine multiple 5V USB batteries to power a Raspberry Pi for a long period of time (months)?

I need suggestions or help thinking this problem through. I want to battery power a Raspberry Pi with multiple USB battery packs (for a remote sensing application) with no need to do anything ...
-4
votes
1answer
133 views

I want to charge my phone with AAs. How do I get that 5V output with max amperage (Would love to draw that 2.1A)

I was just wondering around, looking for how to charge my phone on the go. Because Wednesday morning I'll go camping. I just don't want to buy a cheap chinese power bank to charge my phone once. And ...
-4
votes
1answer
106 views

Do I need an isolated DC-DC converter for this design? [closed]

Do I have to use isolated DC converters for that design or single DC SFDC CONVERTERS' Simple schematic for a LiFePO4 4 cells module balancer Expanded view of converters: this design is to use ...
0
votes
1answer
123 views

Can I get 12V out of a 3.6V battery

I know that is probably an extremely stupid question but Can I get 12V out of a 3.6V battery? I have a faulty LED hula hoop (which currently has rows of LED's, some broken!) and I want to insert a ...
0
votes
2answers
452 views

Step up converter (3.7V to 5V) that will also charge battery!

As a picture often speaks better than words, here is what I'm looking for (the yellow circuit on this picture): i.e. : a circuit that converts 3.7 V to 5 V when a 18650 battery (3.7V) is ...
0
votes
1answer
80 views

Switching Micro-controller from Adapter power to Battery [duplicate]

Currently I am running my micro-controller boards with power adapter(AC to DC). Now I am developing a system which senses AC power and sends me some signal when AC power is gone. The problem is I am ...
0
votes
1answer
76 views

Driving P-Channel MOSFET from MCU Pin While Running on Coin Battery

I made a circuit that uses the DMP2305U P-Channel enhancement mode MOSFET. I connected the pin of the PIC microcontroller directly to the gate pin of the MOSFET. The purpose of this MOSFET to enable ...
0
votes
4answers
106 views

Switching power supply 12V/3.3V for battery powered application with SLEEP mode

I'm designing a 3V3 PSU for 12/6V (lead) battery powered (outdoor) application. Supposed load is 70mA but I plan sleep mode (50uA) with periodic wake-up (ATMega1284P with 32kHz (RTC) crystal). It ...
0
votes
1answer
129 views

Issue powering Shop Vac with Car Battery (via Power Inverter)

I am hoping to run a shop vac off a var battery (this car battery will not be attached to a car). I am hoping to use this vacuum in a remote part of our yard away from any conventual power resources. ...
1
vote
1answer
183 views

Boost with LDO?

I'm working on a project that requires 3.3V from a pair of double AAs. I had thought that LDOs were always buck and if you needed boost you had to use a switching regulator. While doing some ...
2
votes
2answers
69 views

Battery powered project with multiple voltages

I am working on a project which requires three different voltage levels - Motor that can run at 7-12 V. Hall sensor that can run at 5-25 V. nRF24L01+ that can run at 2-3.6 V and AVR (arduino) which ...
0
votes
1answer
94 views

Can I connect Battery positive terminal directly to MCU ADC input Pin?

MCU is powered directly from 3 V battery and I am using ADC input of MCU to monitor the battery voltage to detect low battery situation. I have got good inputs on this site(I need to monitor the ...
0
votes
2answers
77 views

Circuit to put digital amplifier into standby when no audio is at inputs?

I am putting together a battery powered audio amplifier using the PAM8403 class D chip. http://www.diodes.com/datasheets/PAM8403.pdf It has an active low STANDBY pin which turns off the circuits ...
-4
votes
1answer
36 views

Battery Cell Properties [closed]

I have a pair of Bluetooth headphones with a 3.7v, 180mA battery cell. I am wondering if it would be possible to increase the battery cell by replacing it with maybe a 5v or 9v. However I don't want ...
0
votes
1answer
66 views

Stop earth from introducing noise to piezo circuit

I am currently prototyping a circuit which measures pulses on piezo-electric sensors; however, I seem to be having an issue with noise. When the circuit is battery powered (and therefore floating), ...
1
vote
1answer
93 views

Portable device shielding & ESD

I'm working on a portable battery-powered device with a shielded I/O connector for sensors, but I'm confused about how to properly ground the shield and ESD array. Here is a block diagram of my ...
0
votes
2answers
88 views

Figuring out battery life from amp draw?

I decided to take apart one of those cheap handheld fans. It takes 2AA Alkaline batteries. I wanted to hook it up to an arduino as a way to get into electronics, and I wanted to know what kind of ...
0
votes
2answers
170 views

High-efficiency blinking LED circuit

I'm an artist currently working on an installation piece that requires a little more engineering knowledge than I possess. In short, what I'd like to achieve is a 2 LED blinking circuit with battery ...
2
votes
1answer
105 views

Selecting the right battery type and capacity

Have a machine in mind which is intended to be portable (hence weight and dimensions is a constraint), has a miniature refrigerant compressor (like those of Aspen) plus a blower of nominal wattage. ...
0
votes
1answer
64 views

How do simple low power devices store setup when switched off?

I often come across battery powered items that store their state when switched off, particularly 'simple' items like LED bicycle lights (e.g. flash or solid light, changing each time it is switched ...
1
vote
1answer
87 views

Efficient power supply from batteries

I am still new to electronics and I am looking for a low noise and efficient way to provide 5V and 3.3V from AA batteries. My circuit requires 3.3V/200mA 10% of the time and less than 1mA the other ...
0
votes
0answers
79 views

First time enthusiast attempting to build a bottle glorifier with a single LED and battery for portability

I am attempting to make a bottle glorifier out of a single LED that will in theory last for a month without having to turn it off and run it off of some type of battery. That way i could change the ...