So I might need some teaching on the subject of chemistry. I am pretty sure li-po is the pouch batteries, and li-ion is the cylinders. And I also thought they had the same operating range of 3.0v to 4.2v.
But now I just got a SKYRC iMAX B6AC V2 charger. And it distinguishes between the two. It wants to discharge/charge a li-po from 3.0 to 4.2. That’s perfectly expected. But it also has a completely different battery type for li-ion that discharges/charges from 3.1 to 4.1. I didn’t expect that. What’s up with that?
I kinda thought the very old li-ion batteries were recommended for a gentler range of 3.1 to 4.1 back before technology advanced to do a better job of building them. And I thought the term li-lo was used to point out they have a ‘lower’ working range. But I could be totally wrong.
I’ve read the manual and I don’t think you can change it for the type. Although there are 10 customizable programs that give you control of things like cutoffs. I could use li-po all the time, but that doesn’t make sense.
That makes sense gauss163. So how far back was 3.6 nominal? I have 8 cells out of my Gateway computer that were probably manufactured 15+ years ago.
And on my xStar SP1 charger the choices are 3.6 or 3.8 nominal. What is up with that?
Correct to the one that said you want to use the lipo setting. It will charge to 4.2V as we desire. Lithium batteries are a pretty simple charging setup so no worries on how it does the charging. All you care about is the rate of charge and the final charge voltage.
Be sure to check the voltage with a multimeter to make sure it reads correctly. If it doesn’t you can get after market firmware for most of the Imax series that vastly improves things.
But why do ‘we’ desire this?
Judging by the test results it’s not really worth it, a Li-ion cell drops from 4.2 V to 4.0 V in seconds, and from 4.0 V to about 3.3 V it’s got the actual capacity, and under about 3.3 V there’s also not much left.
As i understand it the cell will live longer when you charge up to 4.0 V and discharge down to 3.3 V.
Maybe i understand incorrectly (which is very well possible)
No, you have a good grasp of rechargeable lithium longevity. But there are some people that feel cheated if their battery won’t go the whole distance and the charger won’t get them there. This forum is positively loaded with them.
gaus163 - I get that history. But, within that history it is normal for 3.6v nominal to mean 4.1v full. That charger is using it to mean 3.6 > 4.2. They are mashing the different conventions together. It’s not a big deal, but it is somewhat confusing.
We desire it simply because it can be done basically. I actually charge my batteries to 4.1-4.15v the majority of the time unless they are laptop pulls, then I give them a full charge and let them sit to see how they self dischrage.
Or if I am going for a peak output in a light, then it gets a full 4.2V charge.
All that said I don’t really care what they charge to as long as it is NOT over 4.20 volts. We do not use batteries enough to wear them out by usage, you would have to run your batteries down and recharge them every night to make a noticeable difference is capacity within 2 years time.
Since most of us go weeks/months between charges simply because we can’t use the lights that much. The batteries will simply become outdated before they wear out.
In 5+ years I am positive they will have some better batteries out that we all simply must have. I saw somewhere that the 18650 form factor should be able to reach 6000-7000mA before they have exhausted the lithium technology.
Yes, kind of gives you pause if they don’t even get that. OTOH, a BIG problem is in the technical writing and marketing arena. The engineers probably get it, they likely don’t/can’t/won’t talk to the marketing and writing dept. and those people tend to be pretty poor at translations. We make fun of the Chinglish but it’s a fact of life for this kind of device. Their manuals tend to be mediocre to awful.
Eh, some chemisties are a bit differnt in how they deliver power. Nominal simply means average voltage. Some have a higher or lower average voltage during discharge then others. Plus they want to keep things fairly standard which is why you don’t see things like 3.654v nominal.
The nominal voltage really means nothing to us though, all we care about is peak charge voltage and min discharge voltage.
Well, to the consumer. It actually is the natural voltage of the materials interacting with each other, no charge or discharge applied. This is the voltage they come from the factory at. It’s the best voltage for storage, because the materials are both in their fully natural/relaxed state. Factories don’t take the time to charge each cell to 50%, it’s just natural, and called the nominal voltage.