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Century Helicopter . MTA Hobbies . Model Rectifier Corp

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e-Electric Batteries & Chargers > Li-po charge rate, 2C, 3C, 4C!
 
 
fenderstrat
Elite Veteran
Location: Aston,Pa

sorry,I knew I said I was done with this thread but I feel I must respond


Quote 

YES THEY CAN

Components in Parallel all get the an equal share of the Supply Voltage

Components in Series all conduct the same current because their individual resistances all effect what share of the voltage is across them.

you are contradicting yourself

the only way all 3 cells in a 3 cell pack are going to get equal charges (when charging through the main leads)if is the internal resistance and charge state of all 3 cells are EXACTLY the same,EXACTLY THE SAME,and the odds of that charge after charge are slim

Quote 
he EOS chargers charge through the main power leads and balance the cells through the balance harness **At the same time**

but the cells are being charged THEN balanced,they CANT be balanced AS they are charged as they are being balanced/charged through differnt leads.the battery is charged and AFTER the voltage is in the battery the cells are then balanced.IT IS NOT THE SAME THING,AT ALL.bringing each cell to full voltage at the same time by controlling the input charge rate ensures the cells are all balanced always. the cells are never more than 100 mah apart
the fact that your balaqncer lets the cells get as much as 300mah apart shows that is an entirely diferent process,and this shows that the cells are not being balanced AS they are charging.If the cells WERE being balanced AS they are charging,they would never get that much out of balance

also what does it matter if the charger does 10A if the max charge rate of the battery is 4.4A(2C for a 2200mah batt)

PerformancePlusRC field rep
COMPASS helis field rep
Mini Titan/SE
HBK2
Futaba FASST
07-17-2008 04:02 PM
 
 
"Cam"
Veteran
Location: Asia

fenderstrat

VOLTAGE is what defines a battery.

When the cell is at 4.2V it is fully charged. Doesn't matter how it's done, or what conventions or terminology are used to describe it.

I have not contradicted myself.

Quote 
the only way all 3 cells in a 3 cell pack are going to get equal charges (when charging through the main leads)if is the internal resistance and charge state of all 3 cells are EXACTLY the same,EXACTLY THE SAME,and the odds of that charge after charge are slim

(By the way my diagram had 4 cells and a balancer on each cell)

Out of balance cells must get whatever capacity needed to get them all back to the same voltage.

I will say it again. All that matters is that the cells all have the same voltage before you fly. That is what the balancer and main leads combined achieve.

The cells DO get charged AND balanced AT THE SAME TIME.

It's no different to having an external LBA10, or a V-balancer plugged in and dangling out in the breeze.

Think of it like this: The balancer re-directs some current around the cell, so some power is dissipated across it, instead of the cell, which now gets charged at a slightly lower rate, allowing the lower voltage cells to catch up.

Balancing is a DYNAMIC process. It does not have to be stop-start.

WHY 10 Amps? Because you can charge 2300mAh A123's at 4.3C
THAT'S WHY.

If you have to ask questions like that, stop wasting space in the forum. It's difficult enough for people trying to learn something, rather than trying to prove their RC kit is better, to find what they need to know.

AND the reason charging through balance leads is a BAD idea is because these thin leads have a relatively high resistance and a slight change in temperature (heating) will affect the accuracy of the balance circuit - so it can't do its job properly. That's why most of the power should go through big leads that have nothing to do with the balance circuits.
07-17-2008 04:55 PM
 
 
"Cam"
Veteran
Location: Asia

I have to reply to this one again

Quote 
the only way all 3 cells in a 3 cell pack are going to get equal charges (when charging through the main leads)if is the internal resistance and charge state of all 3 cells are EXACTLY the same,EXACTLY THE SAME

What else is in the picture fenderstrat?

See the balancers? They change how the charger sees the resistances of the cells.

Voltage does not know the difference between a cell, and a cell in parallel with a balancer, it just stays the same across both components, but the balancer can control the current, and hence the power across the cell BECAUSE they are in SERIES with other cells.

AND what do components in series get? THE SAME CURRENT.

Current in balancer goes up, current in cell goes down. Cell gets balanced a bit.



FYI: A123 (LiFeP04) cells are Lithium-Iron cells in a metal can like NiMh cells. They are a cheap alternative to LiPo's, slightly heavier but can be charged at 10 Amps.
07-17-2008 05:23 PM
 
 
fenderstrat
Elite Veteran
Location: Aston,Pa

we were not talking about A123's at all and you do not need a balancer or a charger to charge A123 cells,they can be charged directly from a power source
Quote 

If you have to ask questions like that, stop wasting space in the forum. It's difficult enough for people trying to learn something, rather than trying to prove their RC kit is better, to find what they need to know.

you keep talking in circles,if you want to talk facts fine,I am not getting into a juvenile insult contest with you,I have not insulted anyone and I am not refering to any ONE KIND of "active balance charger"they are a few, FMA was just an example as is TP.I am not trying to discuss which "kit "is better,only trying to show facts,of which you refuse to acknowledge,and continue to make completely false statements based purely on opinion such as your repeated statements that active balance chargers are "expensive and complicated" and "do a less reliable,accurate job"


Quote 
AND the reason charging through balance leads is a BAD idea is because these thin leads have a relatively high resistance and a slight change in temperature (heating) will affect the accuracy of the balance circuit - so it can't do its job properly. That's why most of the power should go through big leads that have nothing to do with the balance circuits

sorry but active balance charging is MUCH more accurate,thats why 2 and 3C charging is possible when charging this way.once again why is it recommended that you charge at 1C when passive balance charging but when active balance charging you can go up to 3C....because its safer,and more precise, controled.your statements have no basis in fact or science only opinion

Quote 
4.2 Amps. The NET & DUO will do 10. – That’s a 5 cell A123 charging at 10 Amps, on each port!

if your charger will do 10 amps max and you are charging 2 batts each battery gets 5 amps.on the DUO each port is 180W max or half power(from YOUR website)


also I just looked at your profile,you do know there are other companies besides HYPERION out there,right?you may want to give someone else a try once in a while.I have a slight feeling you work for, or are sponsored by hyperion,which makes your opinion SLIGHTLY biased.If not,theres a whole world out there besides hyperion

AAAHHHH,the truth comes out,you are a test pilot and technician for a company that sells HYPERION(aircraft-japan.com)

PerformancePlusRC field rep
COMPASS helis field rep
Mini Titan/SE
HBK2
Futaba FASST
07-19-2008 03:15 PM
 
 
TJinGuy
Elite Veteran
Location: Socorro, NM - USA

Cam you are mistaken in your explanation of how an Hyperion charger + balancer works. The main leads carry current into the battery through the main leads. This has nothing to do with voltage. Current is carried by the main leads and then divided up into the individual cells determined by each cells resistance. The more efficient cells grab more and the less grab less. This causes an imbalance between the cells. THEN and only then does the balancer step in and start discharging the higher cells in order to maintain a balanced pack. As fender has said, you are effectively charging the cells and then balancing them. The only difference is that you are balancing them while the charging is happening.

The CellPro 4s charger only charge through the balance leads and handle balancing by adjusting the current supplied to each cell during the charge. This is a far superior way to charge, if performed well of course, and a much faster method because the charger can be more aggressive.

You want numbers? I had a Hyperion EOS 5i + LBA 10 + net cable. Now I have a Cellpro 4s. For a while I used both. At 1C the Hyperion would take about 75min to charge my Mega Power 2100 packs. The Cellpro would take about 62min on the same battery. At 2C the Hyperion (at 4.2A) would take about 45min and the Cellpro (at 4.0A) about 31min. I have now run about 200 cycles through the Cellpro with zero issues. All I know is that it works well and I plan to continue using my setup until something changes.

- Chris

Variety+spice+life+supporting_paper_towel_industry=
King2+Rex450+Protos+Concept30
07-19-2008 06:25 PM
 
 
"Cam"
Veteran
Location: Asia

The 5i is a well-outdated charger

in fact I’m not sure it’s even sold anymore.

The 0606i will charge packs in 35 minutes and if you set the TCS to 95% you can charge in under half an hour.

“Far Superior”? So explaining how something works in electronic terms (that most can find confusing) is inferior to you explaining how something works in round-about terms? Thanks for that.

How does a heli gyro work? How do you adjust the temperature of your shower when you get in? The answer is the system has to change before there is anything to detect and correct.

SO how does the cell pro cope with over-voltage cells?

I think the over-all problem is, you bought it so you have to justify it. (Like most modelers)

My over-all problem is, I want to improve product functionality and safety for the benefit of the hobby. If a product is good, the majority of people will buy it, so I don't have to do much there. What I have to do is make it good. I mean, why are helis not recognized as a national sport and shown on tele along side pool and soccer?
07-20-2008 04:21 AM
 
 
"Cam"
Veteran
Location: Asia

Quote 
your statements have no basis in fact or science

Quote 
do know there are other companies besides HYPERION out there,right?

I am a technician for Air-Craft Japan. There's no secret behind this, and shame on you for not looking at my profile. My job is a science. My boss is very sharp and good with facts. Any grey areas in any product reports I produce I get hammered for.

I rigorously test products from all different brands, I both fly with them daily and take them apart to analyse and test them.

You have no freaking idea how badly I know Hyperion is not the only manufacturer on the planet.

I can tell you a thing or two about makers and branding.

My statements are facts from my combined observations and technical knowledge.

I personally DO NOT care what people buy. But it is very important that we drive this hobby in the correct direction to increase it’s popularity – that is what will make it more affordable and invite more people to take part.
07-20-2008 04:31 AM
 
 
TJinGuy
Elite Veteran
Location: Socorro, NM - USA

Yeah you Cam are a total waste of time. You live in a very small box and are totally closed off to having a real discussion on a subject that is not subjective. I wash my hands of you and your pointless rambling.

But before I do, I will say that the EOS 606i is nothing more than a 5i with a LBA10 installed in the case. Yes an improvement but still an inferior method of charging LiPos. Period. End of story.

See ya ... or not actually.

- Chris

Variety+spice+life+supporting_paper_towel_industry=
King2+Rex450+Protos+Concept30
07-20-2008 04:42 AM
 
 
"Cam"
Veteran
Location: Asia

TJinGuy

You have no idea what I do or who I am and you can say that?

I've had a lot or personal thanks from members on here.

It's a knowledge base for people to get help. Not to write each other off because they both want to prove they know more about something than the other.

You’re “fenderstrats” friend? You fly with him?

What have you done lately to help the hobby?
07-20-2008 04:52 AM
 
 
Bill Ludwig
Veteran
Location: Tucson, AZ

I, for one, appreciate all the help that Cam has provided to me. His suggestions have been timely, accurate and very helpful. He has gone out of his way multiple times to help me with some charger/lipo issues that were making me crazy.

Just my 2 cents...

- Bill Ludwig
07-20-2008 06:02 AM
 
 
Yug
rrProfessor
Location: UK. Herts

It is sad that this has turned into a fight due to different folk defending their beliefs and not necessarily accepting that in fact, there are many approaches to charging and balancing, each with their own merrits. Crikey, we're only talking about charging; just imagine if it were about religion

Quote 
when a "bleed" balancer is used after charging as many people use them,they do "bleed" voltage from the high cells to the low cells,thats exactly what they do
Given the simplicity of balancer design, this is electrically impossible. All a balancer can do is apply an impedance across a cell, according to the result of its comparators.
It is interesting how the same design operates in a very different way whether it is employed during charging or just balancing. In the case of charging, this will limit the current flow through the cell by way of applying an impedance across it, allowing other cells to catch up. If the balancer is connected while not charging, it will again apply an impedance across the cells with greater voltage and bleed off some of the cells current until all cells are equal in voltage (obviously, a bad cell will screw this up on both counts), therefore it's better to allways charge using a balancer to maintain the status quo.
There is an issue over the current rating of the cable and connectors that balancers use. The connector is probably the weakest link where the pins are specified to perhaps 1 or 2 Amps, similar to din41612s. This implies that the primary charge source must employ the main power leads to the battery while the low power cables to the balancer are simply used for balancing where lower currents are observed. This is an issue I am concerned with regarding all balancers I've seen and particularly those that connect between the battery and charger.

Vegetable rights and Peace
07-20-2008 10:59 AM
 
 
fenderstrat
Elite Veteran
Location: Aston,Pa

Quote 
You’re “fenderstrats” friend? You fly with him?


dude did you read the profile I live in Pa and I have never been to NM in my life

once again you are missing the point ENTIRELY

this is not about products at all I could care less about brands and ANYONE on here who knows me knows I usually DONT buy whats popular at the time.I buy whats right for my flying style/performance/budget...Brand name means NOTHING to me this is why I dont have a t-rex, a dx7, a 401 gyro, or tp/fp packs(these are GREAT products they just did not fit my needs/budget/flying style/experience) I base my decisions on whats right for ME not what anyone else is using so drop the fanboy talk its not valid...this is why I used TP chargers and FMA as examples to show its not about brands

this is about you making blanket statements not based on any facts such as "all parrallel chargers are complicated and expensive" and they "do a less accurate less reliable job" and now you are promoting your product using false numbers.

how can you say a FMA charger is less accurate when it keeps all cells within 10mah during the charge not 300mah numbers not opinions


Quote 
It is sad that this has turned into a fight due to different folk defending their beliefs and not necessarily accepting that in fact, there are many approaches to charging and balancing, each with their own merrits


exactly all I was saying is that there are two basic ways to charge and one way you can control input voltage better(fact not opinion)I was not saying any particular charger is better or worse(if you will notice I used the term "active balance charging" at first as to NOT be brand specific)but Cam insists that anything but a hyperion is inferior,not accurate,not reliable,expensive and complicated and its just free marketing and sales pitches which is not what RR is for

PerformancePlusRC field rep
COMPASS helis field rep
Mini Titan/SE
HBK2
Futaba FASST
07-20-2008 01:26 PM
 
 
TJinGuy
Elite Veteran
Location: Socorro, NM - USA

Quote 
In the case of charging, this will limit the current flow through the cell by way of applying an impedance across it, allowing other cells to catch up. If the balancer is connected while not charging, it will again apply an impedance across the cells with greater voltage and bleed off some of the cells current until all cells are equal in voltage

This is interesting. The idea of making the highest cell less efficient while charging in order to slow it down is a good one but not how the LBA10 worked. It applied a load to the high cell and actually bled current out of it in order to lower the voltage. I know this because charging with the balancer shows higher mAh required than without it by about 10%, sometimes higher and sometimes lower. So in my mind that means the balancer was discharging the higher cells just like it does in stand-alone mode. This not only requires more power in order to charge the battery but also increases the time. And in the case of charging at high rates, may fail. As the balancer can only discharge at 2A total. If you were charging a big 3cell at 10A (3.3A per cell), the balancer would likely fail tryng to keep the cells balanced and that could be dangerous.

- Chris

Variety+spice+life+supporting_paper_towel_industry=
King2+Rex450+Protos+Concept30
07-20-2008 02:24 PM
 
 
Jerry Kirwan
Senior Heliman
Location: RichmondTx

TJinGuy

Sorry I don't do quotes. "I am going to continue until some thing changes." That is what happened to me, my batteries got larger. There are many ways to skin a cat. Cellpro I'm sure makes a very fine charger and it appears, their approach seems to work for smaller batteries. IE Cellpro 4s although, I want an actual charger in a case not a shrink-wrapped circuit board { but you get what you pay for}. When you get into larger batteries, charging through the balance lead does not work. Cellpro found this out on the 10S. I have not looked at that charger much since have already made my purchase. I did notice it is encased in a metal case.

I am not an electronics expert and do not have Hyperion's diagrams but it seem possible if you altered the individual cell resistance through the balance plug you could alter the cell's charge rate there for altering the cell voltage. But for me that does not matter.

I have my chargers set to 90% charge and have shortened the charge time by 15 minutes. Take a few minutes for a test, charge a battery to 100% and test fly stop flying after 15-30 seconds and recheck the voltage. You will find the last few percent is what is referred to a "top charge" and goes away very quickly. Look at a discharge graph and it can be clearly seen. When the top charge has been used up you are in the meat of the battery which is where 95% of the capacity is contained.

When I was shopping for a charger {My first since getting into electrics from jets. I have been in this hobby for a long time} I looked at the major brands, and the thing that sold me was if you can charge two batteries it will be twice as fast as charging one battery.{now this was rocket science} I know some people charge two batteries in series but this leads to problems with balancing. I have even seen a diagram with the Duo charging 4 3S 2200 batteries using the balance circuit. I am still checking this out. But until then I chose to purchase a second DUO! At 360 watts of power when I am charging 6s it will charge TWO batteries at almost 2c to 90% in about 30 minutes

Jerry
07-20-2008 04:10 PM
 
 
mmc205
Senior Heliman
Location: PA - USA

I use an FMA 6S charger. It essentially passes charge voltage through the outmost taps (the gnd and highest voltage taps) and monitors each cell, adjusting resistance so that each cell voltage rises the same.
Since the current is coming through the two main taps, one could use the leads instead with large wire to the charger, and only use the rest of the taps (exclude the outermost taps, as the leads are at exactly the same potential.) This is the basis for high current charging. This is why if you want to charge at high current, FMA sells a specific charge plug you solder onto the battery with large wire on the gnd and high voltage sides, and small wires inbetween. FMA in my mind has a superior method of charging as it actively balances as it charges. Items such as blinky balancers are great, but their power dissipation is limited, so when they raise cell resistance to balance during charging, once they reach their power dissipation threshold, the blinky either smokes or lets the extra power/voltage pass into a specific cell, letting them become unbalanced. I hope this helps, as what i've mentioned here is the facutal workings of a balance charger. To my knowledge, both gents were kind of saying the same thing, but it seemed Cam had the hangup that if you were charging through the leads it was different than taps, when if fact you can do either if set up correctly.

My blade mCX can outfly your Aurora!! (in a 1' x 1' x 1' box) :)
08-25-2008 09:00 PM
 
 
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e-Electric Batteries & Chargers > Li-po charge rate, 2C, 3C, 4C!
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