14
votes
How much do lithium polymer batteries expand in volume?
This paper measured a cell, they reported a max of 0.5% expansion over a charge cycle:
Source: Expansion of Lithium Ion Pouch Cell Batteries:
Observations from Neutron Imaging Figure 7
Over the ...
- 82.5k
9
votes
Accepted
How many battery cells in a smartphone?
Yes, most smartphones have a single cell battery.
Most of the components on the smartphone mother board are low powered and run on voltages lower than the typical 3.7V provided by a single lithium ...
- 486
7
votes
Load Sharing charging circuit for Lithium polymer
Why is the MOSFET source connected to load and drain to battery?
As shown in the schematic, the MOSFET has a body diode connected from drain to source. If the MOSFET were attached the other way ...
- 2,621
7
votes
3.7v to 3.3v voltage regulator
A battery's voltage sags as it discharges and the LiPo type is no exception. A 3.7V LiPo battery falls to about 3.0V when fully discharged. You will want your project to continue operating over the ...
- 695
6
votes
Lithium Ion prolonged lifespan
The question is a bit messy.
First, "optimal" might mean different things. Charging Li-Ion to 3.92V will likely yield 70-80% capacity. Is it optimal? It depends on battery use/discharge pattern. If ...
- 40.7k
5
votes
Accepted
Leave phone connected to charger when full or disconnect, drain, reconnect, repeat?
Li-Ion (and their subset Li-Poymer) batteries are much more complex than "above and below 50%".
What is pretty much known to degrade them:
Keeping them charged near 100%. But this is ...
- 9,194
5
votes
Accepted
Replacing three AAA batteries with a 3.7 V, 1200 mAh lithium battery
About replacement of 3x AAA by 1x Lithium:
AAA batteries can be either Zinc-Carbon, Alkaline or NiMH. Working voltages then can be as high as 3x1.6 = 4.8V to as low as 3x1.0 = 3V.
This voltage range (...
- 1,569
4
votes
Should I charge a 3.7 V 500 mAh battery with a 5.2 V mobile charger?
Your "mobile charger" is actually just a 5.2V Constant Voltage power supply, which is unsuitable for directly charging batteries, so no.
Doing so might result in fires/explosions.
The battery "...
- 7,914
4
votes
Accepted
Can I convert L-ion battery backup to supercapacitor?
Just substituting a supercap for a LIon is not going to be good.
A LIon dies if the voltage exceeds 4.2v, the charger will limit to handle this. A supercap dies if the voltage exceeds 2.7v. Oops!
...
- 166k
4
votes
What type of fire extinguisher do I need for lithium polymer batteries?
I've been doing LOTS of research on this for the past several hours on Google. Here is what I've found:
Lithium METAL cells (coin cells like the common CR-2032 and possibly other Li-primary ...
- 41
4
votes
Accepted
Lithium Ion prolonged lifespan
I understand your question. I did something similar in one of my projects some years ago. I wanted to prioritize cell life over runtime, so I just charged the cell to 4.1V and then disconnect the ...
- 147
4
votes
What is the efficiency of a lithium polymer battery?
Your treatment of "real-life" battery efficiency is flawed. The number "97% of rated capacity" is just a measure of current capacity of your battery under your particular charge-discharge conditions. ...
- 40.7k
4
votes
Accepted
Charging a lithium battery to 4.34 V
The chip from the original circuit charges to 4.34V as stated. This would imply that the cell is a high-capacity Li-ion (a type popular in cellphones), so that would also imply you could safely charge ...
- 54.1k
4
votes
Accepted
Lithium polymer battery numbering
Li-ion batteries usually follows the naming convention according to size, so for example an 18650 battery is 18 mm in diameter and 65 mm in length. 0 denotes cylindrical form.
In the past, a tailing ...
- 14.7k
3
votes
Creating DIY ON/CHARGING switch for an Arduino
Q2 is a mosfet used to disable power draw from VBAT when 5V or VUSB is present. Disconnect the trace from pin 3, and place a switch between pin 3 and the trace from VBAT.
Based on what I see on the ...
- 73k
3
votes
Accepted
MCP73831 Li ion battery charger problem with load sharing circuit
I am also using this load sharing circuit and it works for me. You say that the diode is heating while the battery is charged. This means you have 5V at the input and the Mosfet is closed. To help you ...
- 310
3
votes
Tablet battery voltage
You're limiting yourself with the choice of components.
A tablet manufacturer would probably not choose the display you're using. 12 V 1.5 A is 18 Watts of power so this is a very power hungry ...
- 80.9k
3
votes
Accepted
What type of fire extinguisher do I need for lithium polymer batteries?
I think a better way would be to isolate the fire, but there isn't much lithium in batteries.
Simple Guidelines for Using Lithium-ion Batteries
Lithium-ion batteries contain little lithium metal ...
- 82.5k
3
votes
Accepted
Why MCP73871 lithium battery charger IC takes so long?
The voltage where it switches from CC to CV charging is V_REG in the datasheet, which is factory fixed at one of 4.10/4.20/4.35/4.40V ± 0.5%. So if yours is 4.10V then that would explain why you see ...
- 1,211
3
votes
Sourcing 3-lead 3.7v LiPo batteries
You say these things are medical devices. The general answer is therefore that you shouldn't be in there messing with them. You should only replace parts if they are intended to be user-replaceable. ...
- 313k
3
votes
Accepted
Lithium-Ion - leave at full or charge and discharge
Depends on the current draw of the laptop. See the graph below with varying SoC (State of Charge) values. If you draw lots of current, then lifetime is reduced. However, total energy units may ...
- 1,108
3
votes
What is the efficiency of a lithium polymer battery?
Efficiency is a complicated idea to apply to a battery of any chemistry.
The losses in a cell are going to be the impedance of the cell during charging and discharging.
If you have cells of a known ...
- 4,136
3
votes
How much do lithium polymer batteries expand in volume?
Although I cannot compete with the wealth of detail given in previous answers, I think it might be helpful to give you an example why this much extra space is used for a good reason.
A Lipo does not ...
- 346
3
votes
Accepted
How much do lithium polymer batteries expand in volume?
There should be a distinction made between inevitable electrode expansion/contraction due to electrochemistry of electrodes itself at nanoscopic level (which was presented by lapto2d), and "battery ...
- 40.7k
3
votes
Charging a lithium battery to 4.34 V
The maximum a battery can be charged is determined by the chemistry of the battery. For a lithium-polymer battery the charging curve looks like this:
Source: https://batteryuniversity.com/learn/...
- 82.5k
3
votes
Charging a lithium battery to 4.34 V
Different LiPo cell designs have different end-of-charge voltages and end-of-discharge voltages. There are "high voltage" cells that are designed to be charged to higher voltages, and have higher ...
- 46.2k
3
votes
Can I charge a 3.7V 150mAh LiPo battery from USB?
They had 150-190 mAh Li-Ion batteries. All I can find are Li-Po replacements.
What you call "Li-Po" IS a Li-ion cell. It's a pouch Li-ion cell, but a Li-ion cell nonetheless.
Can I charge ...
- 21.4k
2
votes
Why MCP73871 lithium battery charger IC takes so long?
Many smartphones simply don't charge the battery to 4.2V. My phone stops at 4.10 - 4.12V. I believe this is done mostly for safety reasons (exploding laptop battery is bad enough, but a phone bursting ...
- 25.8k
2
votes
Lipo uninterruptible power supply?
Good question.
Li-po batteries suffer the longer they are at a high state of charge (SOC).
Keeping them at 3.7v will for sure slow down the degrading reaction.
This is not at all what laptops and ...
- 233
2
votes
Charging 3 cell LiPo with TP4056 (Protection included)
simulate this circuit – Schematic created using CircuitLab
Thanks for helping @winny
- 31
Only top scored, non community-wiki answers of a minimum length are eligible