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Questions tagged [batteries]

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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votes
0answers
37 views

Dometic cfx50w fridge - how to choose small DIY battery setup [duplicate]

I am looking for some help to understand what kind of battery could power a Dometic cfx50w 12/24/120V compressor fridge, while on-the-go. Here are the electrical specifications: Input voltage (AC) ...
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8answers
875 views

Why does current not increase when batteries are connected in parallel?

I built a simple circuit consisting of two battery holders each including x2 1.5 V batteries, a slide switch, a LED and a 100 ohm resistor. The current I measured with a multimeter when the two ...
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1answer
28 views

Sensor to charge battery

I'm doing a project here. I'm designing my own generator using genset and motor to produce 12V of electricity. The main objective of my project is to produce a 12V from the generator. This 12V is ...
0
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4answers
100 views

How is power consumption from a battery controlled?

Sorry if this is a amateur question, but I don't understand how to control power from a battery. If you just wire it up to the load, it seems it will draw the fastest possible current, possibly ...
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1answer
44 views

Lead Acid Battery [closed]

I have lead Acid Battery which I found in my old stuff I took it out and check the readings with my multimeter the battery is completely dead so I opened the caps of the battery and put few drops of ...
0
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1answer
28 views

Li-ion custom protection circuit module (PCM) design and de-rating

I am designing a custom PCM (protection circuit module) for Li-ion cells provided by a supplier ( they offer PCMs but they do not meet our RF immunity spec ). The supplier-provided PCMs have a charge /...
1
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1answer
123 views

Building a Huge 18650 Battery Powerbank DIY [closed]

I know there are a lot of threads about this topic already, but I still have some questions about it. Anyways, I am thinking about making a 50-80 thousand mAh power bank depending on the batteries and ...
19
votes
5answers
4k views

Why is the battery jumpered to a resistor in this schematic?

I am looking at a schematic for the wifi D1 mini data logger shield that I'm using right now. In this part of the schematic, a coin cell battery powers the RTC. I see R5 is jumpered across the ...
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3answers
61 views

Possible to measure output of each battery in a battery bank?

I've been working on a small project to add electrical to my utility trailer. I have two 12V 20Ah lead acid batteries wired in parallel for running a mix of lights, a winch, cameras, a ventilation ...
1
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2answers
62 views

Battery pack solution for a 5V 500mA project

My project contains: Raspberry Pi Zero W Arduino ProMicro 10 5V RGB LEDs I2S amp that drives a 4Ω 3W speaker Currently I am powering it from a 10000mAh USB power bank. But in order to avoid brutal ...
0
votes
1answer
66 views

10 Amp Current Limit

I have a 28VDC, high current supply (constant voltage) that is required to charge an emergency power supply. These EPS internals are rated at 15 amps max input current, however, it’s stipulated that ...
0
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2answers
74 views

How to heat an e-cigaret coil

I am working on making my own "mod" for an e-cigaret (A mod is the device that controls when and how much the coil is heated up to) I have read a lot about it during the last couple of days, so i ...
1
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0answers
29 views

LCD Dimmer with Variable Resistance Circuit

essentially I'm trying to make a very basic circuit where a 3.7 volt battery is wired to a liquid crystal display, (or LCD), and the brightness of said display is controlled by a pentiometer to ...
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votes
0answers
45 views

Connecting batteries in parallel with different capacities

I have an old 24 V 455 Ah battery used to drive a hydraulic pump. I want to connect a 24 V 180 Ah battery in parallel to increase capacity. Both batteries are Lead Acid, both will be removed and ...
1
vote
2answers
68 views

Why my Battery Protection + Charging + Buck/Boost design doesn't work

Disclaimer: I am a total beginner in electronics, no professional degree whatsoever. I have designed the below 1 cell Li-ion battery protection/charging/buck-boost circuit and I've also designed the ...
3
votes
1answer
127 views

Does keeping a mobile phone plugged in increase its battery's lifetime?

As far as I understand, keeping a mobile phone plugged in would draw current from the source (i.e. an USB port) rather than from the battery. Therefore, the battery would not be used as long as the ...
7
votes
2answers
384 views

How does current flow in this path when all points are at the same potential?

If the potentials at points A,B,C .. etc are at the same potential as the battery wrt the ground, how does current flow then? I'm lacking something fundamentally so it would be helpful if someone ...
0
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0answers
18 views

Charging and monitoring LiPo battery on docking station

How can I charge a LiPo battery (4 cells) without the "classical Lipo Balance Charger". Also, is it possible to monitor the battery level from, let's say a Raspberry Pi?(Using the 4 pins that are ...
0
votes
2answers
109 views

Is there a way to trade off amperage for voltage? [closed]

I was planning on buying a motorcycle battery or some other large battery to charge my laptop, but most of the batteries I found are 12v or lower, and I need around 20v to charge my laptop. Is there a ...
0
votes
0answers
41 views

When to monitor battery capacity

While other good answers have stated why discharging a 12V lead acid battery is hurtful to it, I seem to be unable to find how you should monitor it. Assuming I want to stop drawing current from the ...
0
votes
1answer
55 views

18650 pack building - is it better to have similar batch or similar capacity?

I'm gonna build battery packs. I have quite a lot of experience with 18650 Li-ion cells, but there's one thing I still don't know. I will buy CCA 100 new cells from seller (for example LGEBHE21865). ...
0
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0answers
43 views

Can I use a “battery charge controller” as a “voltage detector relay”?

(I'm very new to electronics/electricity.) I'm currently using a complex ACS712 / Arduino / Raspberry Pi to activate a relay when battery is above 13.8V volts. (See 12V - How to activate an electric ...
-1
votes
1answer
100 views

How many batteries do I need to power a 910mm long LED strip? If I want it to last 30 days, 14 days or at-least 7 days? [closed]

I'm using a LED strip that is roughly 910mm. The LED strip is a OEM 12V LED strip, running at 5W per meter. My project is a LED strip that is suppose to be powered by batteries, this is to be used in ...
0
votes
1answer
100 views

Battery type Identification Request [closed]

I am trying to replace the battery of a rechargeable LED torch, but it looks different than most others that I have seen. I was wondering if anyone can help me identify it, so I can try to find a ...
1
vote
2answers
140 views

How to build an electric rat trap / deterrent

I am looking to build an electric rat trap that acts like an electric fence, one that that can deter or block rats from climbing up a tree. Not interested in killing them. I have a large orange tree ...
0
votes
0answers
41 views

Can a capacitor be used to power a project? [duplicate]

Can a capacitor be used to independently power a project for a reasonable length of time? For example is there a capacitor when completely charged that could roughly double for a CR2032 battery so ...
1
vote
1answer
65 views

Does a CR2032 take damage when connected to a 5V rail?

I've seen applications (Nintendo game cartridges, for example) that uses a coin cell battery for backup power to some RAM-chips (for savegames). When the ordinary 5V is gone, the battery takes over ...
0
votes
0answers
41 views

Creating mobile LED projects with LED strips, USB, and an 8xAA battery pack

I'm trying to make some LED clothing. I'm planning on buying some LED strips, which require a 12V power supply. I plan on buying some battery packs for the power source. To link the power source to ...
2
votes
2answers
76 views

Emergency Shutdown

I am designing a system that is always on. It is powered via POE and it is doing some task that is not mission critical. The system has an embedded system inside that runs Linux. The storage etc are ...
0
votes
1answer
85 views

Li-ion Swollen battery dangerous or not?

I have a Wifi AP and its Li-ion battery has swollen so much that its cover cannot be put in place over it now. Its working but its backup time has reduced to 20%. I cannot put on the battery cover ...
1
vote
2answers
150 views

Do Duracell AAA batteries have internal short circuit detection?

I was shorting a Duracell AAA battery in a SAFE area with proper precautions. After 2 minutes I disconnected the circuit and measured the voltage, it dropped from 2.8V to 2.6V and the battery was hot. ...
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0answers
47 views

Is there a circuit that conserves energy of multiple power sources?

Say I have several batteries. To start all the batteries are "dormant"; there is no current running through them. Starting with the first battery it runs current through it until it dies, wherein the ...
0
votes
1answer
60 views

How to optimize the life of a Lead Acid deep cycle battery?

I have a lead-acid battery : HANKOOK DC24MF DEEP CYCLE 80Ah 12V. In hope of extended this battery's life, I was thinking about buying an identical one and put it in parallel. This way by using "80Ah",...
0
votes
1answer
46 views

Undervolting BLDC motor on electric bicycle

I plan to build a DIY electric bicycle using a standard geared BLDC hub motor (36V and 250W rated, 500W peak). To get 36V rated battery, at least 10 Li-ION 18650 cells are to be connected in series (...
0
votes
0answers
45 views

Could I use my PV inverter at night, feeding it from battery power? What would be needed?

First off, this is pretty much just a thought-experiment! I don't plan on actually going through with this as I'm sure it would void any warranty I have on my installation. Also, I'm totally ...
-1
votes
2answers
87 views

Non-equal batteries discharge in parallel connection

My friend and I have an argument and I want to ask the community to say who is right and who is wrong in their beliefs, and explain it with formulas and laws (if possible). We have two different Li-...
1
vote
1answer
118 views

Replace mains 12v power-supply with 12v battery

A Yamaha digital piano is powered by a mains power-supply. The power-supply states the following input/output values: INPUT 100-240V~50/60Hz 0.5A OUTPUT 12V === 1.5A (Where I have written === there ...
2
votes
1answer
160 views

Why does the voltage of a lead-acid battery drop with load?

My solar power system contains a lead-acid battery but as soon as I use the inverter to power some load, the voltage drops instantly by 1 volt. Why does this happen? And is it proportional to the ...
0
votes
0answers
29 views

Connecting BLE module to Lipo battery and recharge it?

I would like to use a BLE module, where I can solder a tactile switch. There should be also the option to charge the module via USB. Earlier I have only worked with breakout boards, where I could ...
1
vote
3answers
58 views

12v parallel batteries

So after my inverter Cut off, I concluded the batteries were no good, as soon as the inverter the total voltage (of the 2 Trojan 6v batteries in series) dropped to 2v and when switched off slowly rose ...
0
votes
1answer
34 views

Leisure batteries testing/charging

Hi what’s the best/easiest/cheapest way to test 2 6v Trojan 105 leisure batteries. If low how could I charge these batteries as all the chargers I can find are for batteries rated to 60ah Max. The ...
0
votes
0answers
52 views

MPPT controller with battery management system

I'm trying to create a little solar charger with backup battery for my Arduino. I would like to use a MPPT controller for the solar panels. I found a few solutions like the IC CN3722, but all of these ...
1
vote
2answers
97 views

Vehicle Alternator/Inverter system

I have a food van with a stock alternator on the engine, and a 3000w inverter setup. The inverter setup uses 2 Trojan leisure batteries. Somehow the inverter setup is also linked to the alternator (I’...
2
votes
1answer
79 views

Building a circuit to replicate a LiPo battery

We want to keep a Xiaomi Mix smartphone powered on for a very long time (>6 months) with power from the USB cable. This is not recommended by the manufacturer since the battery will be constantly at ...
24
votes
5answers
4k views

Why are off grid solar setups only 12, 24, 48 VDC?

I am looking to produce 50kW for an off grid solar project. Ideally, I'd like to have a high voltage DC battery system with a high power battery inverter and charge controller. I have only found a ...
0
votes
1answer
34 views

Charge 18650 3S pack through USB C

I have 3x 18650s wired in a series, connected to the BMS seen here. The two outputs of the BMS are wired to a MOSFET that drops the voltage from 12 to 5, in order to power an Arduino Trinket Pro. ...
0
votes
1answer
70 views

What are the covers behind the terminals for in lead-acid batteries?

Some lead-acid batteries have two extra covers behind the terminals (See the images below). I understand that the 6 holes in the row in front of the terminals are used to water the cells. But what is ...
0
votes
0answers
51 views

My slayer exciter circuit doesn't work properly

today I tried to make my own Tesla coil circuit according to the schematic below, except that I have changed the number of turns on the secondary and primary so could get a higher output voltage (1 to ...
0
votes
1answer
31 views

Need help with terminology so that I can source a din rail version of this part

Im looking for a 12 VDC power supply that has the ability to switch to a battery when ac power is lost in addition to having some type of AC status function such as an open collector. This part does ...
0
votes
1answer
39 views

Using LM2596 step down with LiPo

i'm doing a project with esp32 (3.3v), dht11(3v-5v), soil sensor (3.3v-5v the cheapest Chinese), nrf24l01 (2.6 - 3.6v). I'm using lifepo4 right now (3.32v) but when the battery drop about 3v, soil ...