The confusing world of Lithium Ion batteries.

[noelH]

LNMC based chemistry lithium ion battery in the Torqueedo. Unknown specific composition. LNMC with higher % lithium  and cobalt pack a higher energy density, but at a $$$ cost. Torqueedo notes for storage over 6 months to fully charge.  Have been doing so the last 6 and now 7th season. Based of capacity and performance I have not noticed any real loss of capacity.

The ePropulsion eLite I'm pretty sure has a battery made of 18650 LNMC cells. They note to drop the battery down to 65% for long term storage.  So I did.  The kicker is they recommend checking monthly to make sure capacity keeps above a critical safe level. LNMCs depending on chemistry self discharge 1-4% per month.

Unsure what type of lithium ion cells are in the Ego chainsaw battery. It's an "intelligent" battery that after a set amount time of no use self discharges to some level.

18650 cells used in the LED flashlights have been charged to full. Both ones in the flashlights and backups in storage. Quality cells and after 7 years of use the only one trashed was due to me leaving the torch on for ? weeks. Cell voltage dropped into the 2volt range. Discharged it down to fraction of a volt and dispose of. Simple diy slow and safe discharger.  A must if you fly lithium powered RC platforms or stress your "smart" battery chargers by using discharge mode.

Started flying DJI quads this year.  Something I never though I would do. Not a fan of DJI. Their "intelligent" batteries are LNMC lithium ions.  Low kv, high torque motors, and low power (watts) quads. They also self discharge.  The kicker is the two models I fly have two different batteries and have different self discharge schedules. Could be due to size(2s and 4s) and capacity.  Both drop down to  the same storage level as ePropulsion.

Realistically I think it is a liability issue for the companies that have self discharging LNMC. In the case of thermal run away the higher voltage fully charged battery would have a more significant negative outcome.  Personally I think it is a bit of a trade off. First one has to consider the actual size, capacity, watt hr of the battery. Then factor in discharging a battery to a "safe" storage level has some inherent risks.

Will be interesting with time as more vehicles and boats become lithium v. gasoline powered in the incidents of fires, explosions.  One of the bad things about lithium is salt water intrusion. Thermal run away can happen and not immediately.  Wonder how many hurricane flooded EVs have been sitting time bombs.

[Doug SC]

Yes, battery maintenance can keep one busy. There is lots of research currently on alternatives to Lithium. I look forward to seeing what will come of it. Thanks for the info on the electric motors.

[Norm L.]

There is a reason why the systems to monitor these batteries are more expensive than a fuse or on/off switch.
Battery science is still swiftly moving. It is no longer a car battery, truck battery or maybe a boat battery. They are being designed for specific applications. Weight, power, life, safety gets played with.
Safety comes first on ships. PCTCs(Pure Car &Truck Carriers)) now need a very advanced and complete fire detection and extinguishing system. EVs aren't afraid of water hoses.
Electric vessels are coming out around the world like small ferry boats, with small bulk carriers carrying coal running on Chinese rivers. Some autonomous. I hope you appreciate the battery boats moving coal to Chinese power plants. And China with the most wind farms.
Worldwide the energy demand for corporate data distribution systems stays ahead of the clean power supplies. And for the growing demand for human cool air.

It is nice that sailboats really don't need any of that. Well maybe with a few exceptions.

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