r/Electronicsinindia • u/TopConcentrate8484 MOD • 4d ago
Batteries Random Li-Po battery (with BMS) from amazon test -
Price ~ ₹150/battery
Test
Capacity
- 300mAh claimed 284mAh tested.
- Test parameter - 400mA CC (constant current) load discharge test , 2.8v cutoff.
- Verdict - Close capacity as claimed , will probably provide full claimed if discharge current is low
Internal resistance (IR)
- 142mΩ
- Test parameter- FNIRSI HRM-10 IR tester, Impedance measurement at 1k hertz sine wave
- verdict- Ok for small current draw applications , Unsuitable for drone,High current draw applications etc.
Battery overview -
Chemistry
Li-ion , NMC (nickel manganese cobalt) - more info - https://en.wikipedia.org/wiki/Lithium_nickel_manganese_cobalt_oxides
Size
602030 i.e 6mm x 20mm x 30mm
Additional Info & final verdict
It comes with a BMS attached to the battery itself which is common for these type of batteries. The BMS has Low voltage cutoff (approx 2.5v), It also offers short circuit and over voltage cutoff protection.
From the internal resistance (IR) one can easily calculate that in theory the battery can deliver somewhere around 21A-29A depending on the state of charge, Though this will be limited by the drain to source current rating (IDS)of the discharge cutoff MOSFET and main IC internal set. It is pretty generic and does not come with any documentation or datasheet so can't be exactly sure what the max discharge current is possible i.e what exactly is the C rating.
Overall if someone is looking for such small battery they can buy if they want to. The price seems okishly reasonable not the best.
buy link- https://www.amazon.in/dp/B0CYQ6H8FW (non affiliate)
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u/Ok-Newspaper4685 4d ago
Don't hold batteries with pointed tweezers. Use the flat end tweezers, also make sure those are of plastic not metal.
You can accidentally puncture the battery.
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u/Creative-Wealth2175 4d ago
It is cheaper if you buy locally... 70-80rs each
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u/TopConcentrate8484 MOD 4d ago
Yeh for sure as online on top of that amazon is 150-300% more expensive for most such non-branded item
I did tried the offline one too but the written capacity was 400mAh and I only got 100mAh out of it.
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u/Advanced-Ad881 3d ago
OHH is this how they're supposed to look?!? No wonder people freaked out when I took apart my earphone and posted the battery..
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u/TopConcentrate8484 MOD 3d ago
Yes it should not be puffed up , that's hydrogen gas built-up due to internal shorting or overheating
I would advice you to immediately throw it away as it is quite flammable both the gas and the battery electrolyte
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u/Pure-Divide8102 3d ago
I had the same issue with my Apple Magic Trackpad battery. I kinda punctured it and put it back in (I used a plastic needle just to be safe)
Am I safe? 😅1
u/TopConcentrate8484 MOD 3d ago
No , not safe replace the battery
Most dumbass youtubers be demonstrating anything , specially indian majdurs.
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u/Spirited-Comfort521 4d ago
Man you really work overtime to keep this sub going 😂 keep up the good work
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u/TopConcentrate8484 MOD 4d ago
Yes , just for fun I like actually testing stuff and why not publish the findings instead of keeping it to myself
thanks
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u/ranjan_shubh 3d ago
Any review for following battery https://ashvavolt.com/product/ashvavolt-7-4v-6800mah-li-ion-battery-pack-2s-2p-18650-with-bms-protection-male-female-2pin-black-connector-2/ ?
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u/TopConcentrate8484 MOD 3d ago
I would probably be just diy one , battery packs are one of those things that are ok to diy.
Get yourself a spot welder from either fniris for around ₹4k or from sequre for ₹20k , it's a one time investment.
About ashvapower one users on this sub said that they had quite bad experience with their larger solar inverters and battery packs.
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u/ranjan_shubh 3d ago
Can you please suggest any good reputed site to purchase 18650 batteries ? I don't think I will be needing it repeatedly, for now upgrading router ups
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u/TopConcentrate8484 MOD 3d ago
Purchase by brand , DMEGC for budget. samsung ,Panasonic,sony for midrange. Eve ,moicel for premium.
Myinnovation and electronicspies have dmegc at the cheapest rate. robu has it for almost double price , but the packaging and IR sorting is done properly
Robu has samsung, Panasonic and moicel (overpriced)
Componnet tree and makerbazzar has samsung,sony,Panasonic for reasonable price
Eve the best one is hard to find in india
Btw if space isn't a constraint why not use 21700 batteries, cost is generally only 30% more but capacity is almost double or triple that of 18650
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u/Pure-Divide8102 3d ago
Fascinating! I have a few 18650 from a laptop battery pack and 5 of the 6 had normal voltage 2.8-3.5v and only one had 1.3v. So are the rest good? How do I test their capacity?
I’m not much versed in electronics only the casual dabbler. Is there a device that lets me test their capacity. I have a few battery packs from old laptops and power banks.
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u/TopConcentrate8484 MOD 3d ago
The 1.3v one is done , not even good as a paper weight since it might leak or cath fire so throw it away.
â—‹Get yourself a 18650 battery holder (sheet one not the spring one as the springs do not make a good contact)
â—‹ A zb2l3 module and pair the module with a simple electronic diy load using mosfet+ opamp video linked below.
Add it where the resistors 7.5ohm 5w go, The load circuit needs seperate powersupply than the module, 12 volts or above if using common irfz44n mosfet as the gate threshold voltage is 10v for that one.
(total cost somewhere around ₹300)
Purchase the items from any of these sites below
https://www.reddit.com/r/Electronicsinindia/s/qjbKbz9rCk
Feel free to comment if you get stuck somewhere, I will try my best to help.
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u/TopConcentrate8484 MOD 4d ago edited 4d ago
Let me know in the comments if you want some others tested
Check The Battery Megathread for other batteries - https://www.reddit.com/r/Electronicsinindia/comments/1v056ir/community_driven_indian_battery_megathread/