I knew it. Sigma was a robot this whole time

[Isaac]

[Tunnelcat]

I don't think he was an actual robot machine. I think he was a human soldier or officer in the military sitting in front of a computer who's sole act was to spread FUD and influence our election, all under the auspices of his government. You'll notice that ever since Putin's little edict came out after Trump won, where he told all Russians everywhere to quit talking about Trump, sigma's been silent here. Too bad. He was, or IT was, at least entertaining.

[Isaac]

No goodbye? What rude robot.

[vision]

I believe he's had a few normal posts on the Overload site since the election.

[Nightshade]

Dude...you really should charge your phone.

[Jeff250]

Dude...you really should charge your phone.

Suddenly a new contender has emerged.

[Isaac]

"5% then charge" is the most thrilling and battery longevity friendly rule.

[LightWolf]

I've heard "No lower than 20%"

[Krom]

It is a lithium ion battery, they don't get the "memory" effect that was a problem for nickel-cadmium batteries. Lithium ion batteries can be safely charged back to 100% at any point in the discharge without significantly impacting its lifespan. They do degrade over time, but there is absolutely nothing that can be done to stop it, they start degrading from the moment they are manufactured.

The majority of cell phones automatically shut off if the battery drops below the cutoff voltage which is typically 3.3v per cell. Below 3.2v per cell lithium ion batteries can become chemically unstable and will degrade significantly faster, and for most cells below 3v a protection circuit permanently disconnects them because most attempts to charge a cell that has been depleted that far will cause it to burn up or explode.

Actually in general it is better to do partial discharges instead of deep discharges on lithium ion batteries, so charge it more often not less. Generally speaking, if you take two identical lithium ion batteries, use one in some device charging it regularly and the other you sit on a shelf with both kept at roughly the same temperature, if you test both batteries again a year later the one that was used and charged regularly will retain a greater capacity.

[Isaac]

Krom, I normally side with your opinions, but this seems like the complete opposite of what we're supposed to do.

I thought I've researched this already. More charging = lower longevity. That's not true?

[Krom]

It is important to know the chemistry of your batteries. Small charge and discharge cycles are better because what actually accelerates the degradation of lithium ion batteries the most is heat. Combine the extra heating from a deep cycle with the chemical instability at lower voltages and they wear out just a little bit faster. Smaller partial cycles don't heat them up as much, this is also why you shouldn't leave your cell phone or other devices with li-poly batteries in a hot car or direct sunlight.

[Tunnelcat]

https://phys.org/news/2013-10-lithium-i ... eries.html

http://cen.acs.org/articles/94/i38/Imag ... nside.html

[Ferno]

It is a lithium ion battery, they don't get the "memory" effect that was a problem for nickel-cadmium batteries. Lithium ion batteries can be safely charged back to 100% at any point in the discharge without significantly impacting its lifespan. They do degrade over time, but there is absolutely nothing that can be done to stop it, they start degrading from the moment they are manufactured.

The majority of cell phones automatically shut off if the battery drops below the cutoff voltage which is typically 3.3v per cell. Below 3.2v per cell lithium ion batteries can become chemically unstable and will degrade significantly faster, and for most cells below 3v a protection circuit permanently disconnects them because most attempts to charge a cell that has been depleted that far will cause it to burn up or explode.

Actually in general it is better to do partial discharges instead of deep discharges on lithium ion batteries, so charge it more often not less. Generally speaking, if you take two identical lithium ion batteries, use one in some device charging it regularly and the other you sit on a shelf with both kept at roughly the same temperature, if you test both batteries again a year later the one that was used and charged regularly will retain a greater capacity.

Recent findings show that a full DOD severely impacts cycle count and lifespan, anywhere between dozens to hundreds of cycles. This is why it's imperative to not discharge lower than 3.87v/cell, or lower than 60% SOC.

[Isaac]

This is all good info

[Sirius]

Hmm. What are the best practices for NiMH batteries?

[Isaac]

Aren't those all super old?

[Top Gun]

"Don't use them" would probably be the best practice.

[Ferno]

Hmm. What are the best practices for NiMH batteries?

Just charge them up every so often.

[Isaac]

There's probably a point where it's a fire hazard.

[Tunnelcat]

Hmm. What are the best practices for NiMH batteries?

https://www.batterystuff.com/kb/article ... ttery.html

[Ferno]

There's probably a point where it's a fire hazard.

Only if you hit them with an absurd amount of amps. A buddy of mine who was heavy into RC racing came near a pack that was being charged and not supervised was being charged at such a high rate that the pack literally exploded -- like a shotgun shell going off -- and the bits smashed into my buddy's face.

Not a pleasant experience.

[Krom]

NiMH batteries and high amps should never mix, it is where the NiMH chemistry is weakest. They have high capacity, but also have a high internal resistance so they aren't suitable for high load applications.

If you need high amps/high load, then lead acid, most NiCD and some LiPoly batteries are designed for it, but it is usually a tradeoff of capacity vs peak power. A NiMH simply can't deliver that kind of amperage and the LiPoly in your cell phone that is designed for maximum capacity would meltdown or outright explode under that kind of load. For peak power, lead acid is basically second to none on the raw amps one can safely deliver, but they are pretty low on the capacity side.

[Sirius]

Thanks TC

NiMH is, to my knowledge, newer than NiCd... not as high-performance as Lithium-ion I presume but I don't tend to see those sold in AA format. Only catch is I've been using them pretty heavily for wireless controllers, which I don't always use consistently, and I'm not sure they hold their charge well when not in use.

[Krom]

Thanks TC

NiMH is, to my knowledge, newer than NiCd... not as high-performance as Lithium-ion I presume but I don't tend to see those sold in AA format. Only catch is I've been using them pretty heavily for wireless controllers, which I don't always use consistently, and I'm not sure they hold their charge well when not in use.

They don't hold a charge well over time so they have to be periodically topped off when not in use, although the same is true for pretty much all rechargeable battery types. NiCd will self discharge in as little as a week, NiMH takes a month or so, some lithium-ion types can last up to a couple months. IIRC lead acid lasts the longest out of common chemistries, but I'm not 100% sure of that.

I had to eventually ditch all our cordless tools because the batteries gave out a couple years after we finally finished the bulk of our home improvement projects. Replaced with fewer corded tools that get the occasional repair or touch up done and store without issue for 12-18 months at a time otherwise.