My take on dendrites

john61ct

1 TW
Joined
Dec 18, 2018
Messages
8,758
Not getting into papers / studies / evidence here, purely practical real world advice

not just about dendrites either, they are just one symptom, but preventing damage in general.

May not be useful for those whose "abusive" use cases requires lifespan shortening.

Charging too fast relative to the cell internal temperature is the culprit.

The damage once done is not reversible.

Prevent it by making sure your charge rate is low enough that the internal chemical reactions do not cause significant temperature increase.

In hot ambients, T-shirt weather and above, 0.5-0.7C is a good limit.

In chilly sweater weather stay well below 0.4C.

As you start getting anywhere near freezing, 0.2C gets to be too fast.

Do not even think about charging below freezing, no matter what the data sheet says.

...

Yes pulsed charging can increase SoC faster more safely than continuous.

That is how the OG "node chargers" were able to deliver 8-10A effective rates through JST balance leads officially rated for well under 5A.

The harmful / dangerous temperature rise effect only happens over time, so building in "rest times" throughout the charge cycle keeps temps lower per Ah delivered.


...

Or switch to lower density LTO much lower susceptibility to low temps, 50-100x cycle lifespan to start with compared to li-ion at 3.6-3.7Vnom.

Get back to 80% in ten minutes, NP. Also can handle DoD much much lower.
 
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