accucel 6 help

Ok, just got my accucel 6 today. I know most of you guys just do safe ranges from .5A to 1A. anyways I got this Tenergy 26650, the stats are located here.

Kinda confused by the .5C5A… is that 1/2 C would be 500mA or .5A? but the 5A? since this is a 12V machine I have to lower my ma to .25? I am assuming 4000mah lasting 2 hours thus getting C=2000mah so half would be 1A. so I’should charge at .5A to be on safe side?

Also can u guys state some safe charging Amps or mah for 18650s. I got another question but I’ll wait for this one to be answered.

2 amps for 26650s and 1 amp for a 18650, you're over thinking it. :D

Hey Scaru, now I know why you have a gas mask. It kinda reeks or am I imagining the slight smell from charging them? Eh I got this Hi drain 18650 the grey one from orbtronics. Ok i was messing around trying to get it to discharge. I saw on youtube I think the guy discharged on pb setting or something. Anyways I discharged on Lipo and I think it went under 3.3v at 1A. Well i charged it back to 3.6, then 3.81 at 1A now it’s stuck at 3.81-3.82v… Worried so I have it on my 2 dollar chinese charger that came with my trustfires any help?

Also in the future how should I discharge them on my accucel 6? Just wonder if the imax b6 woulda been a better choice. So much for smart chargers, lol.

Whether it’s a 14500, or an 18650, or a 26650, or whatever, a 0.5C charge rate is usually a safe maximum. So your charge rate in amps would be exactly half of the battery capacity in amp-hours. So for a 4000mAh 26650, it would be 2A. For a 3100mAh 18650 it would be 1.55A (give or take), and so on.

Actually, Panasonic quotes max. 0.3C for their NCR-series cells, so 0.8A for 2900mAh, 0.9A for 3100mAh and 1A for 3400mAh one.
I just charge all of them at 600mA, because hobby-chargers terminate at 10% of charging rate, and datasheet specifies 60mA for those cells.

They’re just being conservative. I mean, I’m sure everyone around here contacts Panasonic for advice when they want to use their NCR cells in DD lights that pull more than 1C too, right? Hehe. Of course they don’t. Those recommendations are almost always constructed with the advertised cycle life and certain other performance factors in mind.

0.5C charge rates are nothing to worry about. In fact there’s a lot of people out there who charge their quality cells at 1C, and they don’t even get warm. I wouldn’t go as far as recommending that on a forum though.

Uh, well, they quote 2C discharge rate in datasheets, and 0.7C charge rate for any other cells except for NCR’s, so there might be some reason for that… Not just being conservative.

thanks for the advice. Was scratching my head at the .3C (.6A) vs. 1A on the website.

Now anybody got a good guide for discharging 18650 for storage? I’m not certain if it’ll cut off at 2.5v or 3.6v.

Erm, .3C is recommended rate for NCR-series cells (2900mAh, 3100mAh and 3400mAh 18650’s and 2000mAh 18500), your cell is CGR-series for which .7C (1.5A) is recommended rate.

Regarding the discharge rate, I was reading from “notes and precautions”, but if it says otherwise in some other publication, fair enough. But regardless, you’ll find an array of retailers selling NCR cells who recommend 0.5C as a standard charge current, and 1C for quick charge. Maybe they’re being reckless, but I really don’t think so. It’s far more likely that Panasonic are just using the same numbers that are tied to their performance claims in their datasheets.

Scaru is the man:

Just because you’re charging at 1.0A instead of 0.5A for a 18650 won’t impact its life. Probably can be detected if HKJ does an in-depth analysis of them after 200 cycles, but we won’t notice it. :stuck_out_tongue:

Hi guys is there any way to determine the REAL mah of the battery been doing some math and kinda sounda about right. I haven’t tested my theory enough but each tick on the charge/discharge is 1 mah? Haven’t sat thru a whole discharge, but I’m estimating these two batteries to be exactly what others gotten.

Fake Red BRC 3000mah Trustfires: ~364mah
Protected Red Trustfires 3000mah: ~1300mah

You are correct, the digits on the charger indicate the mAh charged or discharged.

To calculate the exact mAh, you need some kind of current logging device.

Plot the mA on a graph, and find the area under the curve. Sounds like calculus, but it does work with a little bit of geometry.

Note that the Accucel-6’s voltage and current measurements are not accurate. Mine often represents 4.175V as 4.2V.

Or you could get a professional discharging equipment, like HKJ.