Battery Question and Curious odd behavior

[hghost]

Now that title does sound odd itself

did not know exactly how to put it

This is not referring exactly to my Super Cub, but I sort of addressed this issue in another battery question before
But will try and make some sense in my questions and what i am trying to find out

I mentioned before how my SC batteries seem to not last as long as before ( not getting to fly to see if they improved any btw )

But I also noticed with the batteries for my X2 Heli, they also have been acting strange as well
( note i do keep these at store charge) I have allowed them to stay charged a day or two when i know
I am going to fly within that day or two.

Ok so this is the battery for the X2 Heli
11.1V 3S 850mAh battery
www.hobbypeople.net/index.php/hp-parts-battery-pack-x2-lipo-3s-580mah-22c.html

So what has been going on, is these batteries seem to have shorter flight time
When i flew last they were hitting LVC at near HALF voltage....

I noticed my SC batteries ( Parkzone ones ) have been doing the same thing, at about HALF the plane loses some power
and acts as if it is just going to shut off....last time I flew they seemed to last longer ( but did not measure the Volts when
I got done-wish i had )

But these Heli batteries i run all the time....the Heli simply loses power and I have to land..sometimes it lands itself..lol

But when i did check the battery they were near HALF.

it is around 11.4 to 11.1 that is about 3.8 per cell something like that when the heli does not want to fly

My SC batteries was near that a little lower, but still near half....not getting below that

Now i know there are those who try and say these batteries have a "memory" ...I do not say that at all.

but my wonder is the Store rate ( HALF ) all the time, should one discharge a battery to near LVC and then re-charge
so the battery does better....does a constant store charge without being discharged/cycled/ a process whatever
affect these batteries in that manner so the battery does not discharge below that HALF for any reason??

Thanks in advance

[flydiver]

Not memory, simply a worn out or a poor battery.
Theoretically the C-rating SHOULD indicate the ability of the battery to sustain voltage during demand. Some planes have low demand (stock Cub), helis/jets often have high demand. To sustain that you need a 'powerful' battery with an HONEST high C-rating. What you are seeing is a battery that can't support the demand > the voltage drops to LVC even thought the capacity has not been used up. The battery may still work OK in a lower demand setting.

Low quality batteries wear out faster and show this trait, sometimes in as little as a few outings. The more the battery is 'borderline' and the harder you push it the sooner it will fail. It has nothing to do with half storage or any sort of 'memory'.

Then the question becomes....where do I get decent batteries? Tough question. I haven't bought any for years so it's not even worth tracking what the battery-of-the-day is in the groups. In general stock batteries from manufacturers are NOT your best option.

[hghost]

Totally agree on the Manufacturers batteries .

The Heli has another one of those odd ends on it and why I bought their batteries ( I hate soldering )

That Heli is wicked fast for a coaxial . Handles wind like it is not even there, why I like it so much.
batteries have done good last year and the first few outings, but now just get no air time at all, well
not like they use to

Odd how many batteries like those 1S that i keep full charged all the time keep their time for the most part
they do dwindle down a minute or two, but not that bad for over 2 year old batteries.

Have to many batteries to keep up with and all those various ends ( I hate the Deans type ends, always hard to unplug ) they are
good, I just do not like them. I like the XT60 and even the EC3 better, they stay tight but are easily unplugged when you have
to unhook them.

to windy to fly planes around here more often than not
this Heli and 200QX quad allows me to fly ...I can fly them in my yard ( less wind -surrounded by tree's )

Thanks Fly

[flydiver]

Learn to solder. Proprietary connectors suck and are against my religion. I hate proprietary ANYTHING that is not absolutely necessary for function. It's just a cheap shot engineering method to MAKE you use their shoddy products, Cub RX/ESC for example.

Note on inflated C-ratings:
The Chinese have found that they don't have to do a lot of engineering. They can just print labels and we believe them. That makes finding a decent battery a bit of a crap shoot. Since the "hoards" buy HK a lot they found they can print [nano] on a battery and give it a high C-rating and it flies off the shelves. The actual performance of this brand is pretty erratic, so erratic it's hard to tell if they are from different sources, wildly abused by people that don't have a clue what they are doing, or might actually be a decent battery. Probably a bit of all of that.

What IS important is that truly high-C rated batteries HATE being left charged for long periods of time. It absolutely ruins them. I would not go beyond a day.

[hghost]

I wanted to note something here about the C rate for charging

Now I have never done this until recently...and it is a silly mistake

But as most know my mind works in moments of time, sometimes not very well ( i have to post notes )

I have many 1S batteries and on those batteries it states can charge Up To 3C for example
they are 1S 3.7v 150mah batteries

well I did not even notice that i did it until a few cycles actually
But I charged them at 3.0 Amps not 0.3 or even 1.0 amp
It has not affected the 1S batteries at all that i have noticed

Also did that on a few other batteries that said charge at 1C . I charged at 1 Amp when they should probably have been
around 0.8 or 0.6 for example. That probably was no big deal on them per say

My wonder is did i mess up a few batteries and not even know it....strange the charger did not alarm and or the batteries did not burst.

have to put a sticky on my charger so I read it and remember to watch what I was reading

I do not know now if I did that to my SC and Heli batts....can't really say one way or the other
I do Not think i did ..But...can't be sure -maybe an issue with those batteries?

for some reason I read 3C...my mind says 3 Amps...so I set it that way

hate doing stupid things...but it happens...i wonder if anyone else has done that in some manner and not even know it?

I have seen other forums where some has asked about the C charge rate on some batteries.

I normally charge this way..IF it is 1300 mAh= 1.3 A......if it is 850 mAh = 0.8 A depending on battery
some allow more Amps some say 1C charge rate some will say 2C or 3C ......you can do more.

Now with that happening, I may have caused the issue I am experiencing

[flydiver]

I don't recall which charger you have. Chargers vary in how they monitor safety. In the end it's the operator responsibility to make sure it doesn't screw up. Most charging problems are operator error, not equipment malfunction.

People with decent monitoring chargers and knowledge have been charging at 3-5C long before the recommendations came out. I regularly charged at 3C years ago. It doesn't seem to do any harm, though there are still a LOT of stalwarts that will claim anything over 1C is destructive. Generally they have nothing to base that on other than 'lipo religion'. Religion is built that way by design, all faith, no information or proof.

The problem with knowing for SURE if you did any damage to the batteries is you have absolutely no units that went through controlled conditions to compare them with. Most 'experiments' with lipos are like yours (semi-erratic) so the results are completely unreliable. But people doing similar things will swear their results are proof.

If nothing burned down or exploded....you did fine. Impossible to really tell if you did long term damage or not since there are so many variable affecting battery longevity.

There are chargers that would have 'caught' your error, but most would not.

[hghost]

I have these Thunder Chargers.
www.hobbypartz.com/73p-ac680-accharger.html

I figure of setting those 1S at 3.0 Amps and it did no harm I doubt IF I did the 1300mAh Parkzone batteries that way
but IF I did it would not harm them either.I think they say 1C so if i did set it it would not have been over 1.0 Amp anyway

Strange how I suddenly saw what i was doing, sort of scared me to be honest..why i asked and noted my mistake

I never leave my Chargers while I am charging, they are within sight.
But the worse is not knowing what i did..whether i did it or not....

that in itself scares me. Why i try and keep a log on all my batteries writing down what i do....simply can't remember sometimes

sticky note will remind me to Look twice and double check

my charger allows it to be set as long as the cell count is correct...on balance charge it allows higher amps
than it does normal charge or store charge for example will not let me set over 1.0 amp, no matter the battery cell count.

scary moment anyway

Thanks again fly for the information very much appreciated

[flydiver]

That's a variation of the ubiquitous 4-button, 50W charger (IMAX B6, Accucell-6, etc.) that are sold all over the place. For small batteries it is quite possible to 'over amp' the charge rate. It doesn't care what it's charging as long as the cell count is correct. All it REALLY looks at is voltage, and cell count if the balance tap is connected and in the right mode, and takes a guess at what it's charging. More than one person has attached a lipo to NiMh charging and got an interesting result.

Luckily, due to the method of charge (CC/CV - constant current/constant voltage), it starts out with a high rate of charge at the beginning (as high as you set it). When the voltage reaches the target, it ramps down the current to keep the voltage constant until it is full. If the current is set way too high it may start ramping down immediately. As batteries age the internal resistance goes up making the charger work harder and the voltage spikes faster which also then lowers the rate. You may not get as complete a charge when starting with a high rate due to the way the charger 'figures out' when to terminate based on the initial charge rate. This only amounts to a few % so is generally not a big deal.

[hghost]

Thanks Fly