Questions regarding Li-ion batteries (Lithium-ion), including proper charging and usage.

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0
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2answers
44 views

Can a 9v battery be substituted with an array of LiIon 3.7v?

I use some audio devices (mixers and effect boxes) that literally drains out my 9v cells (specially the rechargeable). I'm thinking on doing arrays of LiIon batteries (rated at 3.7v-4000mAh each), ...
6
votes
3answers
830 views

Why is balancing used for lithium batteries only?

I have never heard of a lead acid battery having any electronics to balance it's cells, or even any manual way to balance them. But I think all lithium batteries have, or at least lithium batteries ...
1
vote
1answer
53 views

Charging 7.4V Li-Ion battery

I'm making a battery out of two 3.75V Li-Ion cells to go into a speaker system that powers an amplifier. I was wondering on the PCM, how many volts would be max to charge these cells? The cells I have ...
0
votes
1answer
36 views

Measuring smartphone's battery State-of-Charge during charging

I'm designing a mobile device that uses a Li-Ion battery. It is required to indicate to the user the State-of-Charge of the battery, similar to how it's done in smartphones. At first I considered ...
0
votes
1answer
51 views

Charging 2 Li-Ion Batteries via a single charger

I'm currently building a portable USB charger. It uses 2 Li-ion batteries in series connected to a USB port via a 5V regulated buck converter. While a single Li-ion battery would suffice for most ...
4
votes
2answers
443 views

Is charging an empty Li-Ion cell to 50% more or less efficient than charging it from 50% to 100%?

Many devices that are powered by a Li-Ion battery can be recharged over 5V DC supplied by a USB connection. Is the 5V voltage internally converted by the charging logic to something lower, and is ...
1
vote
0answers
67 views

Measuring a 2 cell 18650 battery from ATMega328P

I'm using an ATMega 328P (which will be running arduino code) as part of a project (a bicycle lighting system). It runs off of 2 Li-Ion cells, which both are step-up-regulated to 12V for the lighting, ...
1
vote
2answers
75 views

How to efficiently heat a lithium-ion battery so that it can be charged in sub-zero environment?

A common knowledge and practice on lithium-ion batteries is that they significantly loose the capacity and cannot be charged when their temperature drops below 0 deg of Celsius due to increased ...
0
votes
3answers
138 views

Using Lithium-ion batteries in series

I am trying to build a robot with the minimal components and an Arduino UNO. It needs 7V to 12V input or 5V. So I thought as a replacement of using 6AA, I'd use 2 li-ion of 3.7V in series. My ...
3
votes
1answer
67 views

What affect does charger wattage have on lifetime of LiIon batteries?

This questiuon is generic to LiIon and LiPo batteries but a Mac is used as an example. A Mac 'laptop' is provided with a 85 Watt charger. It is possible to charge it with 45 Watt charger that was ...
2
votes
1answer
191 views

Maximum *charging* voltage for Li-Ion battery

I'm implementing a CC-CV algorithm for charging a li-ion battery. I'm confused what is the maximum allowed charging voltage during CC (constant current) phase. All application notes and datasheets, ...
2
votes
1answer
49 views

Li polymer cells in parallel

I am using two 3.7V LiPo cells in series to power a device. The output of battery is converted to 12V using a dc-dc converter. I want to increase the capacity so that the device can run longer. Is it ...
0
votes
1answer
120 views

What does 1.0 It current mean?

A datasheet of Li-Ion battery states "The current should be maintained at 1.0 It or less". What kind of unit is It?
1
vote
2answers
91 views

Combined chip with LDO and Buck, what use?

I am searching for a Li-polymer 1A charger with a 3V regulated output. I have found Linear LTC355x serie but can't, after reading many "LDO vs Switching" debates, understand the use of both on the ...
0
votes
1answer
133 views

Charging lithium batteries with solar panels

Let's say I have a battery pack made from 3 lithium-ion cells connected in a series (making a battery with around 12 volts). That battery pack has a PCB with balancing function and also protects the ...
2
votes
1answer
109 views

Can I use this Anker Astro 3e to power my arduino through the usb?

http://www.amazon.com/gp/product/B009USAJCC/ref=oh_details_o00_s00_i01?ie=UTF8&psc=1 Will there be any electrical problems? I'm building a arduino controlled car (with a chassis like this: ...
2
votes
1answer
124 views

What battery has more capacity: Lithium Polymer or Lithium-ion battery?

In my project I need a battery with a cylinder of 10mm diameter and 35mm high. I thought only Lithium Polymer technology can create battery for this size. Now I discovery Lithium-ion can have the same ...
-1
votes
1answer
235 views

How to hack a battery powered device to use 1 Li-ion cell instead of 2 NiMH cells?

I want to hack a cordless computer mouse, so it can be used with 1 lithium ion cell (standard cobalt cathode to be extra precise) instead of the intended 2 nickel metal hydride cells. The main reason ...
2
votes
2answers
466 views

Charging and Using a Li-Po battery simultaneously

My system requires a power which is supplied by a Li-Po. however, I need to keep this Li-Po charging at all time so it won't die. Is it possible to connect the Li-Po to my system and also have it ...
0
votes
1answer
151 views

balance charging current for batteries connected in series

I've been using this simple Li-Ion charger for quite a while. It consists of 4x 18650 Panasonic NCR Li-Ion "unprotected" batteries (3.1Ah), connected in series (2+2). Charging was going well with cell ...
2
votes
1answer
239 views

Can someone clarify how to charge a battery without an off-the-shelf battery charger?

I am a college sophomore studying EE, I am currently working on making a simple battery charger circuit for an integrated device. The device has 3 Li-Ion batteries in series for my motors, and a ...
0
votes
1answer
71 views

Charge controller for Li-ion or Li-Polymer battery

I am trying to work out the good charger for Mobile phones, which can serve as good performer for various smart phones out there in market these days & mostly using Li-ion battery. Charging has 4 ...
4
votes
2answers
473 views

What is the meaning of a battery's “cycle life?”

I started to read about batteries, I am interested in lithium batteries, I found a description regarding the stability and capacity/weight, but I read some unclear descriptions like "cycle." What ...
1
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0answers
116 views

Does a crude Li-ion 18650 battery have internal thermal (mechanic?) protection?

For clarification: crude means "it does not have any protection circuit attached". Short history long: I extracted 6 18650 (Sanyo) batteries from an Acer battery pack. They had more than 3V each and ...
2
votes
1answer
79 views

When rechargable battery age, what quality decreases?

When a rechargeable (li ion) battery has many cycles and begins to wear down, what quality actually diminishes? I know it can hold less charge, but is this evident in the potential difference it can ...
1
vote
1answer
91 views

Lithium Ion charging problems - power outages

Does any one know if general charge circuits for lithium ion batteries suffer from this problem: -Flat Battery put on to charge. -A power outage of long duration occurs (say 8 hours). -When power ...
1
vote
4answers
2k views

3.7V Lithium ion battery supply and Arduino Uno

So many people have asked questions related to mine already, but mine is not quite out there. So my question is I have a 3.7V Lithium Ion battery and I need to power Arduino Uno, which requires a ...
0
votes
1answer
454 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. ...
2
votes
1answer
248 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 ...
6
votes
2answers
149 views

How can a Li-Ion battery maintain decent characteristics for nine years?

Turns out Opportunity Mars rover is already working for nine years. It uses Li-Ion batteries to store energy acquired from the solar panels. In my experience Li-Ion batteries when recharged ...
4
votes
1answer
455 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 ...
0
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0answers
61 views

Charging lifepo cells in series

I want to charge my LiFePo cells, which are connected in serial, with multiple one cell chargers. For example using the schematics from this one: Li-Poly battery charger with protection - Schematic ...
-1
votes
2answers
121 views

Lithium batteries worries [closed]

For the last few days I have had this strange fear that an external short circuit would cause an explosive fire of my laptop's Li-ion battery. Three questions: Is it true that lithium ion ...
1
vote
1answer
104 views

Silicon-graphene battery energy density?

A startup called CalBattery is touting that their silicon-graphene anodes for li-ion batteries "will improve the anode specific capacity performance of lithium battery anodes by a factor of 3X." Will ...
5
votes
1answer
276 views

Why Trickle Charge a Deeply Depleted Li-Ion Battery?

I'm looking a this to write my own charging algorithm (really not looking to re-invent the wheel here) and have been referencing this article: http://preview.powerelectronics.com/mag/504PET23.pdf. ...
1
vote
2answers
783 views

Designing 14.8v Li-ion battery charger + 5v power regulator for Raspberry Pi (of other 5v device)

The RasPi requires a steady 5V and to this end I build a power regulator circuit using a LM2576T, similar to the one on page nine of the latest MagPi magazine. This works great with an external ...
7
votes
2answers
163 views

Setting a part's VCC slightly lower than board's supply voltage

I'm interested in using the undervoltage detection feature (in addition to the primary function) of this chip. This IC draws 6 uA (microamps), and accepts any VCC between 1.6V and 5.5V. The ...
4
votes
2answers
520 views

DC-DC converter with 200V output?

First of all, I'm a mechanical (robotics) engineer, so I do not know much about electric power systems. I'm making a mobile robot that should have electrical motors and drive system. The problem is ...
3
votes
1answer
1k views

3.3V Power Failover Supply with USB Li-Ion Charger

I am currently designing a "3.3V@500mA Power Failover Supply with Integrated USB Li-Ion Charger" for a uC project. I want the circuit to draw power straight from USB power when available & switch ...
3
votes
1answer
207 views

Auto-charge 8.2V Lithum-ion battery pack

I am planning a device consisting of a load, a battery, and an external power source. The idea is that the battery powers the system until the external power is plugged in -- then, the external ...
6
votes
3answers
4k views

Measure Lithium ion battery voltage (thus remaining capacity)

What I am working with: I am running my self-made Arduino board (in the sense that I use the Arduino bootloader and code editor) at 3.3V, and powered from a Lithium ion battery, which is USB-charged ...
9
votes
3answers
5k views

Regulated 3.3V from a Lithium-ion (or LiPo) battery

Background I wish to power my circuit with a Lithium-ion or LiPo battery (likely a battery with around 1000 mAh capacity). These batteries have a voltage that goes from 4.2V to 2.7V typically during ...
2
votes
2answers
6k views

Battery management circuit for Nokia BL-4C / 5C Li-ION batteries

Nokia BL-4C / BL-5C are 3.7V, 700-1000mAh (variants) Lithium-ion batteries, which are available in abundance and at very low cost ($4 - $7 a piece), since these are used in entry level Nokia phones, ...
2
votes
3answers
1k views

Lithium Ion charging schematic

I am using the MCP73831 along with a Lithium Ion battery to supply an Arduino Mini project. Is it safe to supply my project directly on the battery? Or should I use a transistor to protect the project ...
4
votes
1answer
495 views

What would cause a watch battery to leak?

I am using a CR1220 Lithium Manganese Dioxide battery to keep a real-time clock chip running during periods when batteries are removed from a device. The battery is only connected to two pins on the ...
1
vote
3answers
807 views

How can I charge my beard trimmer's Li Ion battery from USB?

I have just bought a beard trimmer with a built-in Li ion battery. The charger that comes with it says its output is "4.2V, 600mA". I know Li ion batteries will misbehave (!) if fed the 5V from USB. ...
8
votes
3answers
496 views

Is there any sense in this technique for charging Li-Ion batteries?

This is a replication of this question on Android SE. I feel that it is in fact an electrical engineering question, since it covers batteries behavior in details. Basically there's a claim that the ...
6
votes
4answers
3k views

How is fully charging a Li-Ion battery in 35 minutes possible?

I happen to own a power drill/driver that runs on a Li-Ion battery and ships with a charger that charges it fully in 35 minutes and claims to charge it to 70% in 15 minutes. According to answers to ...
4
votes
4answers
386 views

Overclocking my toothbrush

I use these toothbrushes: http://www.amazon.com/Oral-B-Advanced-Toothbrush-Vibrating-Bristles/dp/B00336EUV8 They tend to run out of battery quite quickly. I'm happy to keep buying more because ...
1
vote
0answers
349 views

How many affordable lithium polymer batteries would it take to safely jump-start a car?

I have a couple of these incredibly powerful 12V battery packs and I got thinking about how feasible it would be to MacGyver an engine starter out of them. These things are rated on the package to ...