Explaining Lithium-ion Batteries (18650 Cell for Diy Projects)
by parvgupta001 in Workshop > Science
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Explaining Lithium-ion Batteries (18650 Cell for Diy Projects)
in short "LI-ION BATTERIES ARE AWESOME"
lets know how...
WHY WE NEED BATTERIES
but it does not hold till their batteries provide us a very efficient way of storing electricity and pumping out when required.
most consumer electronics use the lithium battery due to it benefits over the short term investment of a higher cost
TYPES OF BATTERIES
MEANS THERE ARE A LOT OF BATTERIES TO CHOOSE FROM BUT THE WINNER CAN ONLY BE ONE
HERE LI-ION WINS THE RACE BY HAVING THE PERFECT COMBINATION OF
1.ENERGY DENSITY
2.AVAILABILITY
3.ECONOMY
4.STABILITY
5.SAFETY
6.LIFECYCLE
7.CURRENT DISCHARGE(C RATING)
8.WEIGHT
9.CHARGING
10. EASE OF MANUFACTURING
SIZE COMPARISION(18650)
size bigger than AA alkaline batteries but capacity upto 9 times
volumetric equivalene to a 9v battery but still 3 times longer runtime
APPLICATIONS
Lithium batteries are used every where from your iPhone to your mac-book
but 18650 cells are hugely popular amongst the power bank,laptop battery and electric vehicle manufacturers
because of there greater stability and the formation of cylindrical cell type which makes cooling them easier and have good amount of packing efficiency of 93%.
hardshell casing makes them almost puff up proof.
WHICH CELL TO BUY
lithium battery market is full of various cells but the most difficult confusion is which to buy and which not.
ALL 18650 cells are divided into 3 categories for easy rate and application process
LOWEST QUALITY-$1-$3----all the non branded chinese cells
MODERATE QUALITY-$3-$4---samsung sdi cells
TOP QUALITY-$5----LG CHEM cells,panasonic cells
ULTRA LEGENDARY-----TESLA 2170 or TESLA 18650------not available for general public easily
CHARGING PROCESS
OPTION 1--specially designed 18650 cell AC chargers---cost--$5 for a 2 cell charger
OPTION 2--5 v safe charging circuits--cost--$2
OPTION 3--put a diode(1n4007) in between a 5v charger and the battery to get a perfect voltage of 4.2 v across the battery.(well tested and cheapest for all diy projects)----cost---almost free
SAFETY and HANDLING
LI-ION batteries are like knifes,they are although very useful but works best when worked upon with care and precaution,
although out of my 2018 projects none of them seemed to show a error of li ion battery and none of my battery exploded(undesirably) in my diy projects.
thus to conclude if you handle them with love and care they will give it back.
NEVER PHYSICALLY DAMAGE THEM
DON'T OVERCHARGE OR OVER DISCHARGE THEM
FULL CHARGE THRESHOLD--4.2V
IDLE ZERO PERCENTAGE--3.6V
WITH LOAD LOW VOLTAGE---2.8-3.2V(depends on load)
SAFETY VENTS and CURRENT LIMITING CIRCUIT
These 18650's will never explode thanks to the vents that will let out all the hot gases in case of any mishap.
unlike li-po they have these vents to save them from anything bad that can happen to a battery.
ANOTHER SAFETY FEATURE
most cells have a built in current limiting circuit that will make it almost impossible to harm the cells in any non physical way.
Thus i provide 18650 a 5/5 on safety standards.
TECHNICAL ANALYSIS
FULL CHARGE THRESHOLD--4.2V
IDLE ZERO PERCENTAGE--3.6V
WITH LOAD LOW VOLTAGE---2.8-3.2V(depends on load)
GRAPH SAYS IT ALL
ENERGY DENSITY
293 wh/kg for 18650 cells
the maximum available
1kg li-ion=5kg lead acid
2170 cells used in tesla model 3
LI-POLYMER and Other Lithium Batteries
li-po's are usually used in high current draw application--the only one place where li-ions lack
rc planes rc boats rc quads and all hobby rc stuff uses li-po as they need a burst of power instead of a constant
steady power output.
SEVERAL OTHER LITHIUM BATTERY CHEMISTRY ARE AVAILABLE
the most promising in the future seems the
graphene battery and the lithium air battery.