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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7 views

Verify this charging circuit

This is the circuit I have designed. I want to be sure whether I have designed it properly or not. Here is the Purpose: I am trying to power a Network device 24 hours which requires 9v (600ma). I ...
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0answers
20 views

Is it safe to charge ion lithium batteries with a higher current power supply?

I'd like to know under which circumstances it is safe to use a 5V charger for a device which has a lithium ion battery with an higher maximum current than the correct one. I ask this because I tried ...
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1answer
40 views

Connecting different batteries in parrallel?

I have bought a battery driven load speaker for an upcoming festival. Problem is that the 12V 7Ah battery in the speaker only lasts 12 hours. I need a lot more. So I've bought a 60Ah car battery in ...
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0answers
25 views

How can I charge a powerbank using my phone? [on hold]

My objective to learn how to transfer power from a device with low charge to a device with higher charge by means of wires(micro USB, OTG cables etc)
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2answers
73 views

Mixing same brand batteries with similar voltage

Just about everyone has heard of the problem with mixing new and old batteries, but is it safe to mix various old batteries with each other, regarded that they are the same model and brands, and read ...
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1answer
37 views

Bluetooth Headset Battery life [on hold]

Is the battery on a bluetooth headset significantly affected by the volume of the sound produced by the headset? For example, if I were to listen constantly to music, would it drain noticeably faster ...
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1answer
61 views

Brushless motor not turning

I'am trying to build a drone. Therefore I bought some brushless DC motors This is the only specs I have for the motors : ...
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0answers
32 views

The real flow of electricity [duplicate]

Let's say I have a battery labeled "+" and "-". It is unclear to me which of the following is true: "+" and "-" actually represent the negative and positive terminals respectively, and thus current ...
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1answer
32 views

12Vx2 2Amp Transformer

Please Help me I have edifier woofer x600 and 12Vx2 2 Amp Transformer (Power Supply) is placed in it. The Problem is that i want to run my woofer system on 12v battery. // The transformer has two ...
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2answers
538 views

How to get 3.3V from 2 AA batteries?

I would like to know if its possible to 'step up' the voltage from two AA batteries (3V for Alkaline and 2.4V for NiMH) to a stable 3.3V ? I need to find a good power source for a circuit that I'm ...
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4answers
85 views

Electric potential and the flow of electrons in a battery

I started reading about electricity a few days ago and there are some things that confuse me. What I want to ask about here is the apparent contradiction in two facts that I have read, they are: ...
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2answers
99 views

Derivation of Formula

This is the method for calculating the State of Charge (SOC) of the 12V lead acid vehicle battery. Based on the formula for battery capacity (C) formula $$C = (\text{Current}) \cdot (\text{Time of ...
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1answer
127 views

Use a diode or a MOSFET with a backup battery?

I'm running off-grid 12V domestic electricity, with solar panels and leisure batteries. The charge controller sits between the batteries and the load, and occasionally, briefly, cuts out the load ...
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0answers
32 views

Smart phone micro USB port bypass charging.

The connection terminal inside the micro USB port on my phone is broken so I'm trying to bypass the port by wiring a harness from the charging posts. My battery is a HUAWEI "HB5V1HV 3.8V 2020mAh 7.7Wh ...
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2answers
106 views

How could a rechargeable battery charge itself without an external source?

While I was working on my graduation project I had to charge a rechargeable battery then discharge it and so on.I was shocked when the battery charged itself without any other external sources for ...
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votes
1answer
42 views

Self service kiosk for cell phone and other device battery charging on the go [closed]

We have a micro business in the form of self-service cell phone charging stations that we place in busy areas and people pay a small fee to use. Our question is, with all the new and always improving ...
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1answer
62 views

Lithium battery basics

I have a few things that I don't get about this battery . In our product, when we connect the lithium battery 3.7V charged, things work, but when it's discharged, ...
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1answer
35 views

Changing old batteries in handheld device and replacing the charger

I need them to power a small handheld soldering iron, which had an old battery that died. The original battery was NiCD 1200 mAh 2.4v I am replacing them with 2 NiMH-520rs in series First question: ...
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1answer
40 views

ReusingLithium Polymer battery from an Old Tablet

One of the projects that I am currently working on requires a backup battery source. I have 2 tablets with me that's that's dead (cracked screen) and the Asus one had a 4270mAh battery. I was trying ...
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1answer
70 views

Determine SOC of a Li-Ion Battery

My question is how to measure the SOC (State Of Charge) of a Li-Ion Battery. Now i know it is a very common question and i can google it. So i did google it and read about all the techniques for e.g ...
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0answers
89 views

How do I prevent a bulb from dimming?

I am powering a 4W bulb from a 12v lithium-ion 9.8Ah battery. My problem is the bulb dims after a couple of hours. Is there a component I could introduce to the circuit that would keep the bulb ...
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0answers
40 views

flash circuit in bird feeder

I'm using the circuit in a disposable flash camera to "discouage" squirrels from using my bird feeder. I've soldered across the charge button so it is always in charge mode but I've removed the ...
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1answer
59 views

Reverse polarity protection for LiPo

I'm looking at using the S-8261 for reverse polarity protection. On page 24, it reads R2.. Select a resistance as large as possible to prevent large current when a charger is connected in ...
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3answers
72 views

Capacitor vs battery which cost less per capacity? [closed]

I know that batteries have better density ie capacity per volume. But I want to get the most energy capacity for the money. Which one would would you get? I'm trying to store energy from solar for 1 ...
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1answer
59 views

Way to get high voltage from a watch battery

I'm creating a vary small device that need an high voltage around 50v. But because the device is really small like a pistol bullet, I can only use very small batteries like watch battery or button ...
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2answers
48 views

Battery Capacity Rating

I came across valve regulated lead acid batteries with the capacity rated as 112w at a 30 minute rate. Im not sure what this means. Can anyone please help me further understand this method of rating. ...
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1answer
29 views

PV cell output calculation, when a charging limiter is involved

I need to the charging rate of a battery connected to a 20w PV panel. Due to the regulator on the board though the maximum rate the battery can be charge at is 1A, 12V , due to how this is setup, ...
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2answers
44 views

Arduino remove power if battery voltage is too low

I want to power my Arduino using a Lithium-Ion battery. When the battery is below 3.0V, the power to the Arduino should be disconnected, and when it rises high enough again is should be reconnected ...
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1answer
61 views

Can I run my audio mixer off the battery powering my amplifier?

Background info: I have a small battery powered 25W amplifier/speaker combo. KustomSound CB25X, with two 6V 4.5Ah SLA batteries wired in series for 12V. Fully charged, the voltage seems to be close ...
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1answer
34 views

2x50w stereo vs 100w mono amplifier efficiency

Which is better for efficiency. mono 100w amplifier or stereo 2x50w It is important because I'am building a portable speaker and it is really important for me to use little power. Also which ...
1
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1answer
60 views

Discharge and Recharge of a battery [closed]

Under which value it is not recommendend to discharge a Li-Ion battery? How fully discharging battery affects a battery life? What happens if we leave a battery on charger, even battery is fully ...
0
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2answers
34 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
33 views

Backup battery charger - part 2

2 days ago I asked for any ideas and references for backup battery charger: Backup battery charger For the idea see the image: You actually proposed me some very interesting solutions, e.g. based on ...
0
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1answer
56 views

12V Battery charger voltage - cycle use

I need to charge 12V e-scooter battery with DC-DC converter. Specification of the battery charging voltage is: Standby use - 13.5V - 13.8V Cycle use - 14.4V - 15.0V Can I charge the battery in ...
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1answer
64 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 ...
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1answer
39 views

Backup battery charger

I'm trying to design some kind of backup battery charger - please see the image: Normally, the DC supply is ON, and provides current for load and also charges the battery. Battery should be charged ...
-2
votes
1answer
71 views

How come portable phone chargers tend to use USBA?

How come most portable phone chargers use USBA rather than Micro USB for the output port? Is USBA supposed to be more tolerant? If they use Micro USB for the output (as well), the user could just use ...
-2
votes
1answer
45 views

Can I use both a 12 volt 1 amp wall wart and a 9 volt battery at the same time, on the same circuit? [closed]

Can I use both a 12 volt 1 amp wall wart and a 9-volt battery at the same time, on the same circuit? It will power two fans and I needed 21 volts.
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votes
2answers
29 views

Estimating battery capacity remaining from SLA connected to motors

I have an SLA battery, at say 10 Amp-Hours, connected to 3 high power motors. Each motor can draw up to 10 Amps each (worst case / max power). Using Q = It as an ...
0
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1answer
44 views

USB to 3v converter to power a battery powered FM transmitter?

I have a SCOSCHE FM Transmitter which practically eats up 2xAAA batteries, I was thinking of using my TV's USB power for the transmitter. My search lead me to this 3 in 1 DC-DC USB 5V to 3.3V ...
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0answers
36 views

Regenerative braking torque ca[ability

I have been trying to calculate the maximum torque that be applied to my driveline through regenerative braking on my DC motor, using the equations from this paper: ...
0
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1answer
33 views

How can I determine the charge voltage on my HyperMac battery?

I was gifted a HyperMac MBP-150 lithium ion battery about 1 year ago (150Wh) with very little information about how to use it. I was never was able to charge using a variety of 12V DC adapters ...
0
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1answer
66 views

Should I use a regulator to improve efficiency or safety

I am considering a low power design where I do not use a regulator. The components will operate from 1.9 to 3.7 Volts. The design is powered from two primary cells(Nominal Voltage: 1.5 Volts ...
1
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2answers
157 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
40 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, ...
1
vote
5answers
147 views

how to provide light for multiple 12 v led lights for 2 weeks

I'm participating in an art show soon in which I am making "sculptural light paintings" of which require a few 12v LED strips. They're the kind that work in aquariums and car's taillights and whatnot, ...
1
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0answers
31 views

Could a lipo/18650 overheat during discharge?

Suppose a cheapish lipo/18650 has a typical protection circuit in place, which, e.g., shuts off the battery when voltage gets too low, shuts off the battery when the current exceeds 4A, and prevents ...
-1
votes
2answers
54 views

Replacing battery by supercapacitor

I want to replace a battery, which has a load of LEDs and a temperature sensor, with a super capacitor. How can I calculate the specifications of the super capacitor? Thanks!
0
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0answers
32 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 ...
1
vote
1answer
26 views

What's a reasonable threshold for UVLO?

I see that the TPS61093 UVLO is triggered at 1.55V. However, this boost converter has a threshold of 2.6V. Is 1.55V a bit too low for lipo? If so, how come the TPS61093 is designed this way? Thanks