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Lithium AA and AAA cells - interesting behaviour.

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Siwastaja:
This thread was a train wreck from the beginning. There is only one meaning for "AA lithium battery", namely the primary cell. Recharging is absolutely forbidden.

If you mean a rechargeable lithium ION battery SYSTEM, which is not a "cell", nor "lithium", then say so.

Gyro:

--- Quote from: IanB on March 16, 2024, 02:53:27 am ---
--- Quote from: Halcyon on March 16, 2024, 02:44:12 am ---A word of warning with Lithium primary cells and wireless mice (could apply to other consumer products as well).

I have had issues in the past where a fresh set of Lithium cells measured a voltage higher than what you would expect from regular AA batteries. It was so high that the mouse refused to even power on until the cell voltage decreased slightly. To get around this, I partially discharged the batteries.

--- End quote ---

Not the kind of battery in this thread, but yes, I think Energizer Lithium cells start out around 1.8 V, which is too high for some devices. Same with nickel-zinc rechargeable cells, which also top out at a pretty high voltage.

--- End quote ---

On the other hand, you have Blink cameras, which won't even power up on a pair of fresh alkaline batteries, and must have Energizer Lithium cells fitted.

tom66:

--- Quote from: IanB on March 16, 2024, 02:53:27 am ---
--- Quote from: Halcyon on March 16, 2024, 02:44:12 am ---A word of warning with Lithium primary cells and wireless mice (could apply to other consumer products as well).

I have had issues in the past where a fresh set of Lithium cells measured a voltage higher than what you would expect from regular AA batteries. It was so high that the mouse refused to even power on until the cell voltage decreased slightly. To get around this, I partially discharged the batteries.

--- End quote ---

Not the kind of battery in this thread, but yes, I think Energizer Lithium cells start out around 1.8 V, which is too high for some devices. Same with nickel-zinc rechargeable cells, which also top out at a pretty high voltage.

--- End quote ---

They rapidly drop to about 1.6V under load - within 5 minutes in my experience.  (I built a voltage-based SoC monitor for a product that used these.)  So as long as the product can withstand the slightly higher operating voltage initially (higher leakage current for instance), they're usually fine.

Siwastaja:

--- Quote from: tom66 on March 16, 2024, 11:07:28 am ---
--- Quote from: IanB on March 16, 2024, 02:53:27 am ---
--- Quote from: Halcyon on March 16, 2024, 02:44:12 am ---A word of warning with Lithium primary cells and wireless mice (could apply to other consumer products as well).

I have had issues in the past where a fresh set of Lithium cells measured a voltage higher than what you would expect from regular AA batteries. It was so high that the mouse refused to even power on until the cell voltage decreased slightly. To get around this, I partially discharged the batteries.

--- End quote ---

Not the kind of battery in this thread, but yes, I think Energizer Lithium cells start out around 1.8 V, which is too high for some devices. Same with nickel-zinc rechargeable cells, which also top out at a pretty high voltage.

--- End quote ---

They rapidly drop to about 1.6V under load - within 5 minutes in my experience.  (I built a voltage-based SoC monitor for a product that used these.)  So as long as the product can withstand the slightly higher operating voltage initially (higher leakage current for instance), they're usually fine.

--- End quote ---

Yeah. Standard alkaline cells are also around 1.65V initially and literally every device must deal with that in all operating conditions (temperatures, unit-to-unit variation etc.) so extra 0.15V is not that much, I'd expect these work in 99% of devices just fine (and that's the intended purpose, too).

PlainName:
Dare one ask what the advantage of these are over traditional eneloops or other low self-discharge NiMH? And why do they all list capacity in mWh whereas normal types are in mAh? Seems to me to be scope for exaggeration: are they using the output voltage or cell voltage in working out the mWh?

A disadvantage, ISTM, is the convenience of a USB port for charging. If you're using them on, say, a cat flap that takes 4xAA then you need 4 off charger ports and cables, whereas NiMH is just one charger that will do 'em all in parallel.

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