Battery & iCharger 306b related questions

[jfro]

Just looking to verify what I understand are a few basics about charging lipos. I'm hearing lots of warnings and have decided to look for some guidance on the charging of lipos.
I am starting with four 5000mAh 4s batteries. 2 are 30C and 2 are 40C. Max charge rate on both is 5C. I'm trying 2 different brands to see if there is much difference.

		watts	amps	Charging time in Mins
1c	84	84	5	60
2c	84	168	10	30
3c	84	252	15	20
4c	84	336	20	15
5c	84	420	25	12

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I purchased a iCharger 306B charger with a paraboard with deans connectors. I've switched to EC5's so I assume I can just use deans females to ec5 male extension of 1-2 inches or just buy a new paraboard. I have a converted 550w 28amp computer power supply for now and will probably stay at 12 volts. May upgrade to little bigger power supply, but for now this will suffice.

Some say to charge lipos at maximum rates shortens the life of the batteries. However, some seem to think that with a good charger, this is not necessarily true any more, at least for the batteries. I've also read where some say power supplies and chargers will work better and longer if you stay a little under their maximum ratings. Any opinions?

Is it good practice to first discharge a new battery and then charge it fully to get a baseline on what you batteries full capacity is. Do most people do this? If so, do I have to hook up a regular 12 volt car battery as the power source to discharge the lipo with the 306B?

I have scanned through the 306b manual a couple times and watched a couple you tube videos. I'll do my first charge on a single battery in the next couple days so will know more after that. Looks like there are lots of settings that I won't use in the beginning. Pretty confusing for a first timer.

I read something about quick charging does not charge the lipos 100% because the last 10% or so takes longer as that's done at more of a trickle charge rate to top them off. Out in the field, peeps usually forego that last 10% so they can quick charge and get back to flying. Is this somewhat accurate?



If this is the case, can some tell what settings I need to set for quick charge vs a full charge and are there any longevity issues on doing it either way?

 

[jfro]

No comments because ?
1. Peeps don't use icharger 306b?
2. Dumb questions or not worded very good.?
3. Viewers don't know answer?
4. Subject too long and complicated for quick answer?
5. I should figure it out myself or call dealer?

 

[kloner]

When you ask what charge rates, just depends how big a hurry your in and how much IR increase your whiling to accept created by doing so. Your charger has the IR measurements, do the lab yourself and tell us what you find. I'm not sacrificing hours and batteries to find the answer. i usualy charge 4-6 packs at a time at 1c and it's plenty fast and it leaves them with little damage from it. in general 5c charge rates makes more IR than 1c. again, test it and find out for us. the 5c charge rate packs are a newer lipo tech and it is extremely unstable and very easy to kill from even being close to over discharge. they tend to puff worse than the older style lipos

you never discharge a lipo,,,, ever unless you just don't want it anymore it should never get below 3.7 volt ever. One over discharge and damage begins, gets accumulated like a heavy metal in our body,,, just keeps adding up till the pack isn't what it says on it. mah falls, voltage sags, pack turns to a paper weight


The lipo charging mode is like any other charger on the market. You want tog et confused, Try the FMA brand kilowatt charger

chargers drop there rates as they fill up. to seriously save a pack, chargers like fma only charge to 4.18v a cell as a target, suppose to increase life. it's like 30 seconds of flight in most cases.

 

[jfro]

Your saying if you just go to 4.18 instead of the 4.20, that should increases the life of the battery?

I really don't see a need for me to charge at 5C, but was thinking in the field if I take a generator or have access to AC power, there might be occasions when I want to charge 1-2 batteries at 2C, 3C, or maybe 4C.

I think I mentioned earlier that in my internet readings, I'm seeing a difference of opinion on whether or not it's destructed to charge your batteries at the higher C ratings.

Kloner, thanks for your input.

The charger comes with a temperature sensor. I assume heat his the main issue in charging and battery life and I also assume I could find out what too high a temperature is on the battery surface for a shut down temp.
Would I be wrong to assume if I tried charging at 3 or 4C and used the temperature sensor to shut down at a certain temperature, that might save some issues?





I sent a similar worded question to the vendor and here is his reply


<tt>2. You can use either a battery or power supply to power up the charger to discharge a LiPo. Both of them will work. 3. Your calculations are correct. 1. quick charge for 1 battery. (my power supply is only 18amps. charge mode: fast charge. charge current: up to 20A. 2. same as 1, but for 2-4 of my 5000 mAh 4s batteries. Charge mode: fast charge. charge current: up to 30A. 3. Slow charge to fully charge to maximam capacity 1 battery. charge mode: balance charge. charge current: 5A. 4. same as 3, but for 4 batteries 4s/5000mAh charge mode: balance charge. charge current: 5A x number of batteries.</tt></pre>
Hope this helps anyone who has similar questions. Just one of many questions for getting started.

 

[kloner]

heat isn't a real problem with charging at higher rates, it's the chemical breakdown of the polymer in there that goes away. theres this plastic looking stuff sandwiched in with foil plates, lots of em. they have alot of new theory and rules to use em.

If you abuse a pack too much to where the IR builds up too high and you keep pushing the pack to perform either in or out could very well lead to a fire of some sort or another when the pack tosses in the towel. Just be careful playing around with these things. I tend to use em as advertised and haven't had any major problems.... yet

 

[jfro]

From the 306B manual.

Measuring internal resistance of the battery
In general, the internal resistance of a battery is not a fixed value. It varies over time as the battery loses energy and also varies depending on the load, or how much current is drawn from the battery.

One of the urgent requirements of a battery is low internal resistance. Measured in milliohms, the internal resistance is the gatekeeper that, to a large extent, determines the runtime. The lower the resistance, the less restriction the battery encounters in delivering the needed power spikes.

The iCharger can not only measure the internal resistance of the battery pack, and also can measure the

per cell internal resistance （only available for lithium battery).







Guess I should measure the IR in my new batteries and check them from time to time.

Is the low and high numbers relative to the battery size or type or is it pretty much the same for most batteries in the same class such as 3S, 4S, or 5S, or 6S?

Guess I'm asking is after I measure my IR readings on the new batteries, as the number grows, when do I start thinking about retiring them assuming they are bloated and look fine?

 

[kloner]

I write it on the side of the packs with a date. I pretty much ignore it till i have an incident where a pack was knowingly over discharged then i'll recheck it. I'm not gonna say a number is the end of the pack, but i've noticed a 4s pack will go from 20 to 50 in one over discharge and it never gets better, the problem is next flight is short mah in the cell, but you don't know that except if you watch voltage it'll start to sag about 1000 mah earlier than the flight before when the ir was 20........ and that makes a second over discharge, now the pack total is over a hunded, usualy pushing towards 200mohm............ as a general rule.

Packs have a life of 200 cycles or 2 years in regular tech like turnigy or the like. I smoke em way before that flying fpv... it never fails i get caught too far away and not enough power to get back.... mostly in planks,,,,,, but i've smoked em in multis too. When i work i'll always smoke at least one set trying to get the shot. It's hard, but part of having such a small light source with so much power.