Recommended charging rate?

I bought some Sanyo 3500mah batteries because all I’ve had are cheap 18650s I got from taking apart battery stick power supplies I got at trade shows.

I have these 2 chargers. I usually use the LiitoKala because it has the LEDs that blink showing amount of charge the battery has.

From my dealings with ni-cads years ago, I think the conventional wisdom was lower current charging / keeps the heat down / longer life for the batteries?

On the LiitoKala, I use it at .5a (It’s plugged into a little power cube that doesn’t put much out anyway.)

This page:

https://www.18650batterystore.com/v/files/sanyo_ncr_18650ga_data_sheet.pdf

(the URL says sanyo, but the page says panasonic : )

talks of 1.4a charging current.

what current do you charge 18650s?

Lower current ok, just takes longer? Or doesn’t charge completely or some other reason why I should use a more powerful USB power supply and change the charger to 1A? And even then, that’s less than the spec page says to use.

Or is that just an example of how long to charge at that current? Or max charging current?

THANKS



It depends on the cell. The biggest problem with higher charge rates is the Li cannot diffuse into the carbon anode fast enough which causes the Li to plate on the surface. That in turn causes loss of capacity and reduces the electrode surface area. High capacity cells like the GA are especially susceptible to that behavior.

I usually just follow what the datasheet says. There is no disadvantage to charging slower except just that it takes longer.

All my 18650 batteries are charged at 0.5A. And smaller batteries even lower (0.2A or 0.3A).
Speed never dictates my charge-rate because 3 out of 4 batteries are the same (Samsung 30Q).
And I always have 1 or 2 fresh spares lying around.

So if necessary, I just pop in a fresh one and the other goes (after charging) back in the spare box.

Different rule applies to multy battery lights. Fore those I carry along a spare battery in a spare light.

Gosh! So much to keep track of : )

thanks!

I just charge my 18650’s at 1A… if I need a battery to be charged more quickly, and it’s a higher-drain battery (eg. LG HG2, Samsung 30Q or Sony VTC6), then I sometimes charge at 2A).

Usually I find 0.5A charging to be slow for higher-capacity 18650s… (eg. around 3000mAh or higher capacity).
2000mAh capacity 18650s charging at 0.5A is OK with me, but 2500-2600mAh capacity 18650s (eg. VTC5, 25R) I usually charge at 1A too.

I understand slower charge rate is better, but sometimes waiting too long and more likely to forget immediately removing the batteries from charger if waiting too long to charge… (but that’s me)…

Slower is better. I’m rarely in so much of a hurry that I need faster.

AFAIK 60% of capacity is OK - 1.8A for a 3000mAh cell for instance.