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

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1answer
37 views

How will unmatched lithium-ion cells in parallel react?

We are stocking a portable power pack for USB charging. We tested them when they first arrived and found no issues but after 3 months we tested some of the remaining stock and found about 50% of them ...
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0answers
19 views

Disabling a LiPO balancer when not charging

I'm looking at building a solar MPPT charger / balancer based on combining two designs (I'm not confident enough in my hobbyist skills / ability to not burn the house down to design the whole thing ...
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1answer
50 views

Drain Li-Ion battery by connecting USB +5V and GND

I have a sportswatch which can be connected to a PC via USB for downloading the training information, upgrading the firmware, etc. I have used those features for a year on weekly basis, but since ...
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1answer
58 views

3 Cell Series Li-ION charging with TP4056

I've searched my situation but cannot find my exact answer, I am trying to make 3S Li-Ion battery charger with 3 TP4056 Charger Module. TP4056 Module 1A 5V one cell battery charger i thought if i use ...
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1answer
82 views

Why are 5 Volt 7-8 Amps chargers not available for charging phones quickly? [closed]

Available phone s chargers have either 0.5, 1, 2 Amps rating depending on the batteries (varied capacity) used. Why is it that 7, 8 Amps chargers are not available ? if the limitation is in the ...
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1answer
53 views

Can I wire 6V power packs in series and still use them as individual power sources?

I have 4 x 1Ah Lithium Ion battery packs. These I have two systems, one operates at 5V (usb) and the other requires 20v - 24v. I'm wondering can I power both the 5v system and the 20v system by using ...
4
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1answer
541 views

How can a micro controller turn off itself by closing the VCC line when battery is low?

My board has a Li-ion battery with the capacity of 4000mAh and maximum voltage of 4.25V and minimum voltage of 3.25V . This means that the battery voltage shouldn't get lower than 3.25V. When the ...
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0answers
41 views

Electric vehicle battery balancing

I need to choose a method for my project in for active balancing of Li-Ion batteries for EV application. I read a paper for this purpose: "A Review of Passive and Active Battery Balancing based on ...
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2answers
123 views

18650 Li-ion cells for the laptop battery: with protection circuit or not?

My laptop battery died and I've took it apart to replace the cells inside. Do I have to buy new cells with protection circuit or without it? Googling the existing cells part number LGABC11865, I've ...
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2answers
104 views

Implementation of coulomb counting

How do I implement coulomb counting algorithm ? Once I read the current using a ADC , what processing do I do ? say for 10ms load draws 1mA, next 5ms it draws 7mA. So am I supposed to just add the ...
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3answers
118 views

Connecting a higher-current power supply to a lithium-ion charger will damage the battery. Why?

I am not asking how the battery gets damaged, because that answer is straightfoward. What I am asking is why lithium-ion chargers allow batteries to be damaged by excessive charge current in the ...
0
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1answer
252 views

Charging Li-ion batteries in parallel

I wanted some opinion on my set up here, just to make sure I got the basics right. I have a Li-ion battery charging circuit based on the MCP73113. This is designed to be a single-cell battery ...
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2answers
39 views

USB li-ion charger with usb output

I would like to power my robot with li-ion batteries. The logic is 5V so I thought about something like this http://www.powerstream.com/n-charger.htm. This does exactly what I want - it is charged ...
0
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1answer
57 views

How can I regulate the voltage of a Li-ion battery with the least drop out voltage?

I have a one of these: descriptions: full charge voltage : 4.2V cut off discharge voltage : 2.75V capacity : 4000mAh size : 18650 And I want to get 3.3V from it. but the problem is I can't use ...
0
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1answer
108 views

Powering circuit and Arduino with single power source

I am trying to power an Arduino Uno as well as my circuit using Li-Ion batteries. They are 2 18650 Lithium Ion batteries (rated at 3.4 V each = 7.4 V total). I have this battery plugged into the Vin ...
0
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3answers
98 views

Double Li-ion charging circuit logic

I'm currently trying to adapt a single li-ion battery charger based on the TP4056 to work with charging more than one battery. The idea is to use a logic circuit that is controlled by the IC's "FULL" ...
2
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1answer
67 views

How to keep rarely-used Li-Ion batteries functional?

I have many gadgets around the house that I don't use often, recently I notice that a battery failed on an Mp3 player not used for a year. The battery now has a life of 1 minute from the original 5-7 ...
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1answer
46 views

Lengthen charge times with batteries

Would replacing a 3.7v 1000mAh lithium ion battery with a 3.7v 5000mAh lithium ion batter make my projects last longer between charges?
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2answers
119 views

Using Li-Ion battery while charging

I'm trying to design a custom intelligent electronic cigarette battery, but I'm more of a programming guy. I know basic electronics, but I need some help with the details. I've sketched up an outline ...
0
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1answer
104 views

Finding the right battery?

I have a 5v circuit that's running on a 3.7v 1000mAh battery. I got it changing just right and the circuit is running fine but it doesn't last as long as I want it too. So how can I find the right ...
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2answers
114 views

How do phones charge their battery at seemingly any rate with no issues? 500mA or 1A or 1.2A depending on the charger?

If most use some sort of li-ion battery, and those batteries like to be charged in CCCV format how can my phone charge just fine at 5V, 500mA or 5V, 1A or 5V, 1.2A just fine (actual current delivered, ...
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4answers
142 views

Will voltage or current determine a diode drop for this battery charging circuit?

I am using a li-ion battery charger IC that regulates an output to 4.2V. I have a schottky diode in series with the output that then connects to the battery. How do I determine the voltage drop? If ...
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1answer
53 views

Is this Li-Ion safe? [closed]

"TIANPENG li-ion 1300mAh 7.4V" is what the text on the battery is. Do you need internals of the charger? The battery 'case' (or whatever is holding packs of cells together) is cracked in some places, ...
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1answer
571 views

How To Blink LED's with MOSFET in response to Music?

trying to blink LED's by music. i've done this circuit no problem: Now wish to accomplish the same thing using an N-channel Mosfet. I tried this circuit, and got no blinks. Also no success with ...
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2answers
92 views

Alternatives to relay/contactors in DC circuits

I wanted to switch a 60Vdc line to ON/OFF using a 60Vdc controlling signal for some kind of a feedback system (yes both are 60Vdc). Presently I have two options visible: Solid State 60Vdc input ...
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1answer
64 views

Getting 12V out of 60V battery bank

I have a 60V battery bank with 16 Li-ion cells in series. I was wondering if I could get 12V output by connecting a wire across 3 or 4 cells in series and using it to control the 12V dc fan of the ...
0
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1answer
54 views

Is there any way to control a 12Vdc relay using 60Vdc line

I have a 60V li-ion battery back with PCM board attached to it for protection. According to the PCM datasheet, under fault condition the PCM cuts off the load and thus isolates the battery bank. The ...
2
votes
1answer
124 views

Temporary, high-power energy storage

I'm currently building a small, portable human-powered charger for supplying a 1W led. I salvaged a dynamo core from a torch, but I'm unable to use other components inside since the torch is only ...
3
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1answer
69 views

Charge a Lipo with only Constant-Current Stage?

I'm following this standard algorithm: http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries Algorithm for charging LI-PO batteries? but am wondering if I can get ~80% of the ...
2
votes
2answers
331 views

Is it ok to use an old phone as an universal battery charger?

We know that a charger is just an adapter that supplies a constant voltage (5 volts usually). The actual charging circuit is in the phone itself. With a bit of soldering and wiring, can I use my old ...
2
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2answers
179 views

Can Lithium Ion Batteries be used to generate heat for a RC Hot Air Balloon? Any particular heat-generating device?

First the background: OK - this is a personal project that I've always been interested in trying but never got around to it - a remote controlled hot air balloon. Sadly I am not technically-inclined ...
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2answers
142 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
279 views

Simplest possible circuit for charging a li-ion cell

I want to create an ad-hoc single cell li-ion charger. I have a buck step-down that can supply 4.2 volts. If I connect a 1 ohm resistor in series with the lithium cell, the current should go down to 0 ...
1
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1answer
866 views

Calculating battery percentage using an Arduino

I'm doing a little project using a Lipoly charger and a 2500mAh 3.7V battery, both from Adafruit. I'm trying to display the percentage left on the battery. For that I'm using this little sketch : ...
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3answers
162 views

Replacing li-ion cells in handheld drill battery [closed]

I am considering to replace the 18650 battery cells in a 3S1P 11.1V cordless drill battery pack rated at 1300mAh, with three 2200mAh cells from a salvaged laptop battery pack. One of the four cells ...
0
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1answer
87 views

Can you use an iPad battery with an Arduino?

I'm looking to power an Arduino based project with a sufficiently large lithium battery so it can run for hopefully a week or more of constant use (ultrasonic based traffic counter). For large ...
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2answers
99 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), ...
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5answers
1k 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 ...
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1answer
256 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
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1answer
122 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 ...
1
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3answers
635 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
505 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
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0answers
131 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, ...
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2answers
140 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 ...
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3answers
198 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
106 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
763 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
53 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
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1answer
172 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?
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2answers
113 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 ...