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Questions tagged [lithium]

Lithium batteries are disposable/non-rechargeable batteries, often found in button/coin-cell form and sometimes in cylindrical cell form. Lithium batteries are used in portable consumer electronic devices, including watches, cameras, calculators, thermometers, etc.

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What is the truth about 1.5 V “lithium” cells?

At least one manufacturer out there is marketing "Lithium" cells in familiar AA and AAA sizes, as direct replacements for those standard 1.5 V sizes, boasting the typically better than alkaline ...
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5answers
4k views

Why are lithium ion cells mostly round?

After watching some tear-down videos on YouTube with various lithium battery products (portable chargers, laptop battery, power tools) they all (apart from mobile phones / tablet battery) seem to ...
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4answers
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Pulse-powering heavy loads with a coin cell

Lithium coin cells are rated for fairly low standard current draws, on the order of 1 to 5 mA. Also, while they allow greater pulsed current draws (i.e., periodic bursts), this appears to be ...
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3answers
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If a lithium cell is said to have a capacity of 20 Ah, does that mean all 20 Ah can be used?

Toshiba's SCiB 20 Ah Lithium titanate cell is said to have a nominal capacity of 20 Ah. The cutoff voltages are 1.5 V and 2.7 V. Does this mean that all 20 Ah of charge exist between those two cutoff ...
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1answer
21k views

How much lithium in lithium polymer batteries?

This document summarizes aircraft travel guidelines for batteries: http://safetravel.dot.gov/documents/airline_passengers_and_batteries.pdf It has two categories of lithium batteries: 8 grams or "...
7
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1answer
1k views

Boosting a Lithium Coin Cell

I made a board recently and just started checking it out yesterday. I used a typical lithium coin cell and a boost converter (Microchip MCP1640). With a battery plugged in I get no voltage out of the ...
6
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3answers
4k views

Lithium Button Cell Characteristics

I am working on a small wireless sensor platform and trying to figure out power supply options. My power budget is approximately: .2mA constant, ~15mA for .1s every 2-3s, and 60mA for 10s very ...
6
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1answer
4k views

Lithium-ion rechargeable battery, shelf life

For Lithium-ion rechargeable batteries, that have never been charged, or been charged like 2-3 times at most, some 2-3 years back, and having since-then been in packaged condition, what should I ...
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2answers
28k views

How can I safely charge 3 lithium 18650 batteries to use in one pack?

I'm working on a project to make my own super-bright bike taillight using an emergency flasher LED (something like this:) The LED package requires a 12V input, but from what I've read from other ...
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2answers
1k views

Lithium coin cell battery showing randomness in voltage

I have a CR2032 coin cell battery and using that I am operating a BLE 4.1 module. When I connect a fresh battery in to the module the voltage shows 3.3 V, and after continuous communication with ...
5
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1answer
31k views

How to Calculate Theoretical Capacity and Energy Density of Li Ion Battery

Specifically if the cathode and anode are known materials how do you calculate the theoretical capacity and energy density of the full cell? For example if you have a Lithium Iron Phosphate cathode ...
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3answers
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Smallest lithium battery backup?

I'm considering putting a small lithium battery on my Super OSD Pro boards. The battery would provide power to the RTC. I am wondering how small can you get a battery? I don't really care about ...
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2answers
4k views

Making a lithium polymer circuit

I want to create a circuit that will power my Raspberry Pi using Lithium Polymer. My knowledge of LiPo is rather low and I believe they can get dangerous if used incorrectly so I turn here. THe ...
4
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1answer
115 views

What is the typical RMS noise of a lithium battery?

Take a typical CR2032 battery, if it is not discharging, what is the typical variation in voltage over a short period of time (eg a few seconds or minutes)?
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1answer
1k views

What is this Externally-Triggered Fuse?

In the datasheet for an overvoltage protector (TI BQ771815) there is a device I don't recognize: It is used in the datasheet as a fuse which can be opened by an external signal from the overvoltage ...
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2answers
848 views

Safe Lithium Battery Management

I'm building a device that needs to run from Lithium batteries. I am well aware they need to be charged/dis-charged properly to avoid damage and explosions. To my knowledge a charging system has ...
4
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2answers
961 views

AP4306 has paralleled two op amps in it's block diagram, is that possible?

Thank you for taking some time to read this. I've recently come across a nice constant voltage/current source (http://www.mouser.com/ds/2/115/AP4306A_B_C-271586.pdf) called an AP4306. Upon reading ...
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1answer
199 views

Protecting a coin cell from high current spikes - using a capacitor or not?

I've built some prototypes and try to gather some data from them. Skip below the two horizontal lines to read more about it. Original Question Brief summary I would like to know whether it is ...
4
votes
1answer
5k views

USB to 3-cell Lipo charger?

I have a data-logger project that needs to run from a 3-cell Lithium Polymer battery. It has 5v and 3.3v regulators to provide regulated power to the system. I want to build the battery into the ...
4
votes
1answer
199 views

What are the possible causes of sudden extremely high internal resistances in Lithium batteries?

Not a duplicate, just to separated a good question from Does a crude Li-ion 18650 battery have internal thermal (mechanic?) protection? Short history long: I extracted 6 18650 (Sanyo) batteries from ...
4
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1answer
231 views

Are Lithium Thionyl Chloride Battery usable in my vibrating environment? Are they safe?

I have to power a circuit subject to constant vibrations (10-15 Hz with an amplitude of ca 10 millimiters) with a battery and I was thinking of a Lithium Thionyl Chloride Battery. The circuit has to ...
4
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1answer
148 views

Running a battery in propylene glycol

So I was thinking about building a deep water camera housing. The housing would be filled with a non-conductive fluid to counter the pressure at depth. Although fluids like purified water or ...
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2answers
13k views

Will a device charger with higher current output necessarily charge an electronic device faster?

Charger specs Charger type : USB Charger Voltage : 5V Amp : 2 Amp Freq : 60 Hz Battery specs Type : Li-ion Power : 7.4 Wh Current : 2 Ah Discharge Voltage : 3.7 V Charging limit voltage : 4....
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1answer
5k views

How many battery cells in a smartphone?

Are most batteries built into smartphones (e.g. iPhone) single cell batteries? If so, why might that be?
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4answers
2k views

protection circuit Lithium-ion batteries

I am designing a lithium-ion battery in my project but I am a little confused in regards to certain aspects of the protection circuit of lithium-ion batteries.I know about the different stages of ...
3
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3answers
573 views

Are laptop cells balanced while charging?

I have little-to-no knowledge about how the laptop batteries work. I know there is a microcontroller to actually verify the balancing between cells (and in case blow up a fuse or something similar). ...
3
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2answers
613 views

Regulator and charging in a portable device

There are quite a few similar posts on this subject but I'm a little confused about the best way to proceed in my specific project. All my previous regulators have been linear types (eg: 7805, LM317 ...
3
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1answer
633 views

MAX1555 Alternatives

As you know, the MAX1555 is a popular single cell lithium polymer charger. It can take USB power directly, restricting the charge current to 100mA or so. Are there any other MAX1555 alternatives ...
3
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1answer
92 views

Power supply circuit concerns

TL;DR: Go to the bulleted list below. As a weekend project I tried to design a simple power supply (without sofisticated switching mode ICs, since they are very hard to find where I live). So after ...
3
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1answer
2k views

Charge Li-Po battery with TP4056? (Or what else?)

I bought a single cell Li-Po battery and two different charger modules (one without protective circuit and one with protective circuit) from AliExpress. The Li-Po battery has a protection circuit ...
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2answers
2k views

Can I drop 4.5 V to 3.7 V with a diode?

I have an RC helicopter with a dead 250 mAh lipoly battery with a voltage of 3.7 V. Could I use 3 button cells at 4.5 V and a diode with 0.7 voltage drop to power the circuit, which is somewhat ...
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2answers
2k views

Lithium Battery Charger IC - Charging and Power

Basically, for the circuit I'm making, I need it to be powered by a Lithium battery. Also, this Lithium battery has to be able to be charged via USB. I have seen external chargers for doing so, ...
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2answers
7k views

How should I connect multiple Lithium Polymer battery packs in parallel?

I have an application for which I need a relatively high amount of current @5V. I was thinking of connecting four external USB battery packs like these in parallel, as they output a nice regulated 5V ...
2
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1answer
222 views

Flat coil inside rechargable lithium battery

Take a look at this de-labeled smartphone Lithium-Ion battery: What is the coil used for? Possibilities I thought of: Wireless charging - unlikely because the outer metal foil would screen the ...
2
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1answer
427 views

Isolation between cells for battery charging & testing

I want to charge Lipo battery packs and possibly other chemistries too. Six cell packs for starters. But hope to handle more and less. Perhaps a lot more cells. For electric vehicles, skateboards, ...
2
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1answer
1k views

PWM lithium-ion charger

I want to make a custom lithium-ion 18650 standard cell charger as I will be charging 100s of them (recycling old laptop batteries). Base on my research, lithium-ion cells use constant-current, ...
2
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1answer
1k views

How to design a Lithium-Ion battery pack?

I have a project that I am working on that requires the use of a rechargeable battery pack. The major issue I have is that the battery pack needs to be as slim as possible. So far all I could find are ...
2
votes
1answer
539 views

From Li-Ion to Li-Po battery: design a new battery pack for old mobile phone

I have an old working mobile phone. The battery, a compatible 3.6V 500mAh Li-Ion is almost dead (the original one was 800mAh). Is it possible replace the battery pack with a 1200mAh or so Li-Po ...
2
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2answers
681 views

Buck/boost to charge lithium battery from solar and alternator?

I have a 105Ah 12V Pb battery in my 4x4 for the fridge, it is charged by solar panel or the car's alternator through a DC-DC charger connected to both. The charger is however only for Pb batts and I ...
2
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1answer
137 views

Switch off this single cell lithium hi-power LED driver with protection circuit

I've been goofing around the internet trying to build my own flash light with a single 18650, with low voltage protection circuit. For now this circuit can already achieve following ideas: Standby ...
2
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1answer
163 views

Charging circuit for Lithium Iron Phosphate batteries

This question is regarding charging circuit for Lithium Iron Phosphate batteries. I have a pack of Lithium Iron Phosphate batteries rated 3.2 V / 7.5Ah which will drive a circuit. According to the ...
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3answers
222 views

Is it safe to have 4V continuously supplied to a lithium battery?

I have a compact digital photo camera that will be on for very long periods(for a time-lapse video). It is powered by a Lithium-Ion 3,7V, 720mAh battery I want to supply 4V to the battery terminals, ...
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2answers
1k views

Confusion regarding the design of Lithium Ion PCB

From this site and many others, it seems to be universally recommended that a lithium ion battery not be discharged lower than 3.0 volts. Most actually recommend to stop discharging at around 3.3 ...
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2answers
7k views

What are the tolerances for the maximum current a battery can supply?

After a lot of research and experimentation I have come to learn that the sentence "This is a 1.5V, 2800mAh battery" is entirely a lie. (i.e., the potential difference between the terminals of a ...
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3answers
107 views

What are my prototyping options when working with smt devices?

I have been working on a project which will allow me to learn how to charge Li-ion batteries. I recently purchased some simple PMIC's made by Texas Instruments. I received them the other day and ...
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1answer
63 views

Lithium Titanate Battery Pack(LTO)

I saw arguably new and interesting lithium battery which is Lithium Titanate Battery(LTO). It has high discharge and charge current characteristic. Also, it has lower degradation graph when comparing ...
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2answers
331 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 ...
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2answers
2k views

Charging phones via solar battery chargers

For a school project, I want to make a solar iPhone charger (specifically for the iPhone 4) and I've spent about a week looking up stuff all over the Internet, and I'm stuck for the hundredth time. ...
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2answers
39 views

Multiple dc-dc Converters mid-tap on batteries connected in series

I want to design a 48v system for an RV with multiple Lithium batteries connected in series (either four 12v or two 24v lithium batteries). I like the idea of a 48v system to reduce the size of the ...
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1answer
47 views

Measure battery pack cell voltages with analog multiplexer and instrumentational amplifier

I'd like to measure the voltages of individual lithium based cells (LiPo, LiIon, LiFePO4) in a battery pack (up to 4 cells in series), using an ADC. I was thinking about the following approach, using ...