Nitecore batteries failing after 6 months

[pluckytree]

I bought 24 NiteCore rechargeable batteries 6 months ago and they've performed really, really well. About a month ago, one of the batteries failed to charge (I tried 3 chargers). Last week, a second battery failed. I contacted Nitecore and they told me that if I let the batteries discharge too much, they won't charge anymore. I've tried to educate them about Lithium-Ion batteries and about deep discharge (which isn't the case here), but they are having none of it. If a battery can still operate a camera up to the point it is charged, the battery should be able to be charged.

Has anyone else had similar problems? I don't really want to buy more of this brand so if there are other recommendations, I'd love to hear them!

[TomMac]

I've been using 2 set of Nitecores for about a year +... no problem to speak of.   Sometimes things just happen, i think so far I've been thru 30 charge cycles with them.

But they are right about to low a discharge hurting Li-ion cells...Many if below 2.5v will appear to be dead due to safety curcuit bulit into the cells. Some chargers can bring them back, some cant.

In Arlos tho, the drop out is aprov 2.75 to 2.8v so that should not be a problem.

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Lithium ion chemistry prefers partial discharge to deep discharge, so it's best to avoid taking the battery all the way down to zero. Since lithium-ion chemistry does not have a "memory", you do not harm the battery pack with a partial discharge. If the voltage of a lithium-ion cell drops below a certain level, it's ruined.

[pluckytree]

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TomMac wrote:

I've been using 2 set of Nitecores for about a year +... no problem to speak of.   Sometimes things just happen, i think so far I've been thru 30 charge cycles with them.

But they are right about to low a discharge hurting Li-ion cells...Many if below 2.5v will appear to be dead due to safety curcuit bulit into the cells. Some chargers can bring them back, some cant.

In Arlos tho, the drop out is aprov 2.75 to 2.8v so that should not be a problem.

==========================

Lithium ion chemistry prefers partial discharge to deep discharge, so it's best to avoid taking the battery all the way down to zero. Since lithium-ion chemistry does not have a "memory", you do not harm the battery pack with a partial discharge. If the voltage of a lithium-ion cell drops below a certain level, it's ruined.

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The batteries were not in deep discharge. Deep discharge is a battery industry term and is very, very often confused with full discharge which just means "the battery ran out." Apple, who deploys more individual lithium ion batteries than anyone in the world, does a great job of explaining it at a consumer level. In one sentence no less:

"If you store a device when its battery is fully discharged, the battery could fall into a deep discharge state, which renders it incapable of holding a charge"

If a rechargeable battery was highly prone to failure merely by getting to the point where the device shuts off and then charged later that evening, the world would be plagued with hundreds of millions of battery failures a year. Now if your cell phone battery dies and you put it in a closet for 6 months, that's a different thing. That's deep discharge.

Hope that helps explain how it works.

[pluckytree]

Oops, I forgot to provide the URL:

https://www.apple.com/batteries/maximizing-performance/

If you drop off the maximizing-performance part of the URL, there are some very detailed pages that are very easy to understand. Clearly Apple has a very strong vested interest in preventing battery failures, so they've done their homework.

[TomMac]

I do understand the difference...

As I stated, the dropout on the Arlos is way above any low discharge state.... the cutoff voltage on arlos is aprox 2.75 which is way above any voltage that could cause a problem,...

Sometimes the batteries just go bad tho.