How Slow Can Li-Ion Be Charged Safely?

[High Efficiency]

Many discussions abound regarding fast charging but relatively few regarding slow charging.

I'm planning to make some 1x 1S4P and 2x parallel 1S4P long run time lights using 3.4Ah cells. This will mean 13.6Ah and effectively 27.2Ah packs.

Most chargers are limited to 3-5A which would leave charges rates of 0.11C - 0.18C.

Does charging at rates this low pose and risk or harm to the packs over time?

 

[alpg88]

No harm, packs will be just fine, i have several lights and devices i build that have 1s4p to 1s6p cells, charged with 1A and 3A usb circuits. No issues that i can see.

 

[DIWdiver]

Right, no harm there. But you do want to terminate charge correctly, which means not exceeding the max voltage AND stopping charge after the current drops below C/15 or so. You DONT want to float charge them at the termination voltage. This would degrade their lifetime.