LG Chem battery pack degradation test 

But wouldn't less restrictions equal a lower current draw giving more run time?

@@peetbronkhorst5473 no. Higher air flow = higher moment from impeller to motor (need to move more mass per second) = more current. It is the same with centrifugal pumps, where is specified minimal pressure on output, or you would overload motor. It would be opposite on volumetric pumps, like a gear pump for hydraulics.

TY just what i was wondering . I am looking after my ebike batteries but i wondered if i was wasting my time if there was age degradation .

I used to recover cells from laptop batteries quite a lot (before eBay banned the sale of 18650s) and most were definitely not in as good condition as these. Surprised at how well these kept their capacity: they must not have been used much.

Pretty much my own observations. I've seen some rarely maintained radio batteries (some different cell standard) and they didn't last half as long as drill or laptop batteries using 18650 cells. Control circuits are a different topic, while some of the drill battery cells were probably still good, due to some weird counter reaching EOL in the ic, they couldn't be properly charged, rendering the entire pack useless. Talk about planned obsolescence

​@@TheSpotify95when did ebay ban sales of 18650s? I still see loads of them on there

Whilst those cells may have most of the original rated capacity, this is measured at only 500mA of current. What REALLY matters is how well the cells perform under the load that your application demands. . For example I recently harvested used LG cells from a Dyson V8 vac. They measure about 1850mAh at 1A which might appear like they are "almost new". However when pulling 15-20A that the Vac needs, the tired cells have about 40% the original capacity in Watt Hours. The vac only lasts a few minutes on high! . Those INR cells might be OK for some low current array, but are useless for their original application (hence discarded by my GF).

Imagine: Mary Barra had them better cells. Then her Bolt's would not have gone up in smoke.

@@LawpickingLocksmith ????🧐

@@G1ZQCArtwork She is the useless chick trying to run GM. All their Chevy Bolts had to be recalled because of LG-chem batteries.

Bloody hell, these cells can take up to 10 Amps! No wonder why they are used in high drain appliances such as vacuums!

I double checked, the data sheet says 10A max. I imagine this is for short bursts only. This is surprisingly common for these cells, but I would not like to do it too often.@@TheSpotify95

You got that backwards. The more restriction, the more load, the more current, the shorter live.

​@@johncoops6897 nope. No load on a centrifugal fan is when there is no airflow across it, that's why the noise pitch goes up when you block the inlet. Contrary to intuition the motor is LESS stressed in this condition despite sounding like it's being damaged. The only limitation is heat dissipation as most centrifugal fans are air-over cooled so the motor eventually overheats from lack of cooling, not an inlet restriction.

@@johncoops6897 Think about it. With restricted air flow RPM of impeller shoots up why? Restricted air flow means less load. I tried it myself on impeller I build myself for cleaning PC from dust. I just use it not for suction but for shooting air forward. With no restrictions on airflow the RPM goes down and load up. Cause motor has to constantly accelerate new and new air up. If you do not believe me watch some videos from Marius Hornberger or woodgears from Matias wandel. They build and explained it countless times in their videos. When they build dust collectors for they's workshops.

@@johncoops6897 The air for a fan is the same as wood for the saw. If there is no wood on saw. Sawblade goes on max RPM and no load. Like a fan in vacuum. But when cutting wood the sawblade RPM goes down and motor struggles you could even stop it from turning = stalled. That is a fan with endless air supply. You could even stall it too with hi density gas = liquid. Maybe someon here would be able to explain it better.

​@@josifvissarionovich5320you are wrong in this case obstruction to air flow the motor has les air to pump so current is lower, the opposite of volumetric pumps where obstructions to flow would bog down the motor and cause higher current. Haven't you ever blocked a Vacuum cleaner and heard it speed up as it has no through put ???

I would guess notebooks and even cell phones are in fact harder on the batteries - because the cell/cells get charged to higher voltage (4.35 V instead of the typical 4.2 V for 18650 cells. The same as the secondary protection here - but that one is most likely only meant for it to not be a fire hazard, if the primary voltage regulation fails. The primary regulation is probably at 4.2 V per cell) and they also often get left and or used with the power supply ("wall adapter") connected, which keeps the battery charged up to that voltage for extended periods. They also often get hot and heats the battery indirectly, even if the current draw is so low that there is not much heating from the internal resistance of the battery. The laptop I have now has a "80% charge limit" that I have activated. It's quite new yet - but hopefully, that will prevent it from having like 50% degradation in just 2-3 years, like the previous ones I have had. Anyway - the cells in the video still seem very good at 93% after 6.5 years and also that the degradation is even - not one or a few cells that's really bad - which often the case in battery packs like this

There is no balancing here. Just protection.

@@johncoops6897 the S-8209B also balances, no way you have cells within 25 mV without balancing or even have a pack last that long anyways.

​@@DooMMasteR - LOL, too little knowledge can be dangerous. . First, a S-8209B doesn't really "balance" anything. It simply "normalizes" cell voltages, and only during charging, and only providing suitably large Mosfets and Discharge Resistors are installed. . During charging, if it senses that it's particular cell is already fully charged, it can enable a shunt to "bypass" that cell while other cells charge further. . That process can only work if the "bypass" components can dissipate more current than the series charger is supplying at that time. On THIS PCB, there are no such components installed. . The S-8209 or any other kind of simple "single cell" chip cannot balance _between_ cells because it only connects to one cell and has no way of knowing what the others might be doing. . Anyway, the video says it's using S-8215 chips. Irrespective of what chip is used, just because a datasheet says "balancing" does NOT mean that it really does that. ... need to put brain in gear before opening mouth 😉

@@johncoops6897no, it also works with a lot less current, as the resistor "burns" additional energy to the part that still charges the cell. Also that's literally what passive balancing is, these circuits just burn a little energy, they are not supposed to support fast charging or anything so even 25 mA or 50 mA of balancing current are just fine.

@@DooMMasteR - whilst that may sometimes be true.... as I said before, there is no balancing being done here on this PCB. PS. those resistors you mention... They ain't there either.

I agree!!!

Depends if Diode has a battery resistance meter that he can use?

@@TheSpotify95 All you need is a multimeter and a little math.

But laptop batteries are rated for 2 or 4Amps per cell and tool cells are rated for 15-25A per cell.

That's like hoping for a easy solution to a low performing member of a sports team.

Ci pulisce casa 😂😂

If you think of "no load" as in "vacuuming free air" you are right about the consumption But it spins slower under that condition If you restrict the flow of air (by actually vacuuming something) there is less air to interact with the blades of the impeller, so the motor spins faster due to less resistance. But it also draws less current in that case. So the more you "use" your vacuum, the less current it draws

Stop the flow of air by blocking the hose, and the speed goes up as the motor is loaded less. Because it is running in its own vacuum then.

@@pizzablender yes and the current draw goes down. But it isn't what someone would logically expect. You'd think while it was, "working" it'd be working harder then. At least I always did until I learned otherwise. He tested the motor in open air. Which would be it's highest current draw too.

LG Chem is a great brand for quality lithium cells. Such as Samsung, Panasonic and Sony-Murata. I'd personally stay away from chinese brands.

The fan is a closed impeller, it's a fairly standard design, the casing has diffusion vanes to spread the discharge air evenly instead of a single ducted discharge like in volute configurations.

Hi what is the board called? It sounds very useful, as long as its not too expensive for me

Would be an incredibly useful comment if you had mentioned any clue regarding how to find this board. Without this, the comment is just infuriating.

I don't know what circuit you're talking about. If your circuit design requires a 0.24 ohm resistor but you only have 1 ohm resistors then use four in parallel. The resulting 0.25 ohms is only 5% off.

@@eDoc2020I'm talking about the battery tester circuit the 0.24 ohm resistor is a shunt resistor so i can't simply use a 0.25 ohm one(i think) the masurment will not be accurate

@@arminkiaei9748 The circuit has a calibration potentiometer so the slight difference can be accommodated. If you still want it to be perfect put 6 ohms in parallel with the .25 ohms to bring it exactly to 0.24. Or a 6.8 ohm parallel resistor would give about .241 ohms. That's only half a percent off which is probably better than the tolerance of your resistors. For the op-amp you need a model which works properly when the input voltages are near the negative rail. I do not believe the TL081 meets this requirement. Any "rail-to-rail" op-amp should be compatible.

@@eDoc2020 thank you so much for your help. so i use two resistors in series or parallel to get the best result.

@@arminkiaei9748 You'd be using five resistors in parallel: 4x 1 ohm 1/2 watt and 1x 6.8 ohm.

Isopropyl alcohol would get them apart. It's excellent for removing hot melt glue, it practicaly falls off.

@@ProdigalPorcupine Thanks for the tip!🙏