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

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1answer
27 views

Will back emf damage a lithium ion battery?

I am prototyping a battery-operated toy containing a couple of motors - these motors are driven by a pair of h-bridges which are controlled by a micro controller. I'm running this whole thing from a ...
1
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2answers
53 views

Voltage drop when measuring battery capacity

I'm trying to build a battery capacity tester for Li-ion batteries. I made this schematic using Arduino: While bush button is not triggered arduino only shows battery voltage on Serial & when ...
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4answers
98 views

Replacing 18650 cells in laptop battery with greater capacity ones

My laptop battery died and I can't find a replacement (old laptop) so I'm going to need to replace myself the 18650 cells it has. It is an 8-cell battery (a series of 4 banks of 2), making the whole ...
0
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1answer
61 views

Li-Ion charging ic with 5V input and battery voltage between 3.9V and 3.6V [closed]

I am currently in search for a battery charging ic that has a variable output voltage (so that I can set it to 3.6V to 3.9V) or a fixed range, similar to what I would like to have. But why would I ...
1
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1answer
64 views

How to prevent DC motor from dropping voltage of supply when switching on

I have a circuit which uses an ATtiny85 output to a transistor (S9013), which will trigger a relay that controls a motor. The reason for the transistor to relay is because I do not have a transistor ...
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0answers
59 views

Building a UPS for Raspberry-Pi

I am trying to build a 5V/2A uninterrupted power supply (UPS) for my rPi B+ using LM7805 and some phone batteries (3.8V/0.5A and 3.7V/2A) or any of the 6 pcs 18650 batteries (3.7V/2A) that I have ...
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3answers
123 views

Relay not switching correctly, controlled from ATtiny85, output to motor

I have an ATtiny85 switching an NPN transistor, which will in turn switch on a relay that will run a motor. Everything is run off a 3.7V 18650 Li-Ion battery, but I have since moved over to a variable ...
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3answers
40 views

ATtiny85 to control a relay, which will turn on and off a motor

I am trying trying to control a 5V relay (SRD-05VDC-SL-C) with the ATtiny85. I have a simple sketch uploaded (Blink without Delay example): ...
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2answers
46 views

Low voltage cutoff circuit

I'm powering an attiny45 from a lithium ion battery; using these batteries the voltage cannot get below 3volts or it will damage the cell. How should I go about cutting the voltage out? Software, or ...
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1answer
85 views

Charging li-ion cell using constant-voltage only

Introduction Various resources [1] [2] state that the optimal method of charging a li-ion cell -- such as one found in a mobile phone -- is to charge at a constant current (usually <1C) until a ...
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1answer
60 views

Using LM2577 boost converter to charge the 2S lithium ion battery with an input of 15W at 5V

I am trying to design a Lithium ion battery charger that can charge a 2S battery. The input power will be 15W at 5V. I am thinking of using LM2577 boost converter to efficiently step the input up to ...
0
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1answer
79 views

280LM Led Headlamp needs FCC certificate?

Do I need FCC certification for my 280LM Led Headlamp with 1800MAH Lithium battery which is rechargeable only via USB? More details: Watts out: 3W Lithium-ion Cells: 103450 Energy Content:1800Mah ...
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2answers
93 views

Do I need a balance charger if i use a Protection Circuit Module for Li-ion batteries?

I'm looking into making a battery pack for a portable speaker system. If I use one of these: ...
0
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1answer
96 views

Cheap and easy way to power MCU from Li-Ion, and keep it powered during charging

What is the cheap and easy way of powering MCU from Li-Ion battery, with automatic 3.3V regulator disconnect while charging, to properly charge the battery? I've came up with something like this: Is ...
0
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2answers
103 views

Charging Li-ion batteries in series

Recently, I bought a DC 12300, a 12V battery with high capacity 3000mAh and I got a charger 12.6V and 500mA output. First thing I did when I got the battery, I measured its voltage and it was 2V. ...
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2answers
92 views

Wrong behavior li-ion battery charger

I followed this tutorial to build a li-ion battery charger circuit, I made two circuits (the last one better than the first), but any of them works as expected. Schematics (I copied from the page ...
0
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1answer
42 views

Li-Ion Charging - Constant Voltage Stage

The charging curve for Li-Ion batteries (explained here) has a final constant voltage stage where the charge voltage plateaus and the charge controller slowly shuts off the current until it reaches ...
1
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1answer
170 views

Arduino and N mosfet lithium battery charging/discharging measuring capacity

I need an Arduino based lithium battery tester that uses N channel Mosfets to switch On charging from and external power source and discharging through a 2 Ohm resistor. I have no issues with either ...
0
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2answers
81 views

Charging li-ion batteries with protection circuit

If i'm using a protection circuit like this one: http://www.batteryspace.com/pcbfor148vli-ionbatterypack5alimitwithfuelguagesocket.aspx and 4, 3.7v li-ion batteries. Can I use a simple 16.8v dc ...
0
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1answer
112 views

SIM908 Li-Ion charging with 6V solar panel

So, I want to know if I can hook up a 6V 2 watt solar panel to the Vchg pin on a SIM908 gsm/gps module and trickle charge my 6Ah LiPo battery that way. A little background... So, I have completed ...
0
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1answer
70 views

What is the maximum voltage of a Lithium Ion Battery

My question is about the maximum charge voltage of a Lithium-Ion cell. I have charged my battery pack with 8.4V (the maximum voltage). The pack is a Samsung ICR18650-26F. The pack has a smart ...
3
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1answer
94 views

Dual smart battery design and PCB layout

I have a system that is powered by a 7.4V Lithium-Ion battery. The system, which is a combination of processor module and sensors, draws a varying amount of current at varying voltages (5V, 12V, -12V, ...
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2answers
78 views

Can I use lithium coin cell battery CR2320 for discharging about 80 mA at 3 V?

I need to use a coin cell battery as a source for supplying 3.0 V at about 70-80 mA for about 2 hr per day. The coin cell battery I want to use, its spec sheet doesn't tell me much about what I want ...
0
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1answer
77 views

charging 10Ah li-ion batteries in parallel

i'm trying to charge a 5Ah single cell li-ion battery using bq24090 charger controller (up to 1A fast charge current) in parallel with a current boosting circuit. Overall controller should supply fast ...
0
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1answer
95 views

Can I connect directly a 3.7V 18650 li-ion battery to a mobile (cellphone)? [closed]

If I remove the 3.7V battery from my mobile, is it possible to connect to the battery +/- terminals a 3.7V li-ion 18650 battery?
1
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1answer
91 views

Are there any high energy density (i.e. zinc-air or lithium-manganese dioxide) batteries without high internal resistance?

For my wild life camera, I want a small cell that can provide 0.5W for 8 hours or more. It doesn't seems rechargeable lithium ion batteries have that energy density. I don't mind if the cell is ...
0
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0answers
57 views

Power with Battery + 1wire to i2C

I'm creating a project with Raspberry PI B+ where I will get energy from a truck (12~27v) or/and a solar power (6v 5.6w) to charge a battery and keep the device running until the battery finishes or ...
0
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1answer
54 views

Effects of C Rating on Battery Life

A polymer lithium ion battery is rated at 3.7v, 6600mAh and a maximum discharge current is specified at 3.3A. I take it this means the battery can be discharged at 3.3A and last for two hours since ...
1
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1answer
75 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 ...
0
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0answers
73 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 ...
0
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1answer
70 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 ...
0
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1answer
753 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 ...
1
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1answer
98 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 ...
1
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1answer
59 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
votes
1answer
566 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 ...
0
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0answers
63 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 ...
1
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2answers
543 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 ...
2
votes
2answers
126 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 ...
3
votes
3answers
214 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
1k 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 ...
0
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2answers
61 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
101 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 ...
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votes
1answer
261 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
173 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
votes
1answer
97 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 ...
0
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1answer
50 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?
2
votes
3answers
204 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
votes
1answer
108 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
198 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, ...
1
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4answers
230 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 ...