Turnigy Accucell-6...Am I missing something?

[tre]

Would that metal hanger add a lot of resistance too?

Also, I thought we are always extolling the virtues of independent charging channels. This can't do that unless you charge one battery at a time? Am I wrong?

 

[pae77]

Would that metal hanger add a lot of resistance too?

Yes, I suppose so.

Also, I thought we are always extolling the virtues of independent charging channels. This can't do that unless you charge one battery at a time? Am I wrong?

No, you are not wrong. . . it's still a charger with only one independent channel. However, one way of using one channel to charge multiple batteries together at one time is to do so by parallel charging as depicted in the photo posted earlier above. And, as I noted earlier above along with the first photo in this thread showing parallel charging of two batteries, Li-ion cells are self balancing when charged in parallel (so balancing leads are not needed with this particular method), and it works well and is quite safe as long as some simple precautions are observed.

But that said, about 95% of the time, I simply charge one cell at a time with my hobby charger. I just wanted to point out that it is easy and pretty simple to charge more than one Li-ion cell at a time with a hobby charger for those who might be concerned about the limitation of only having one channel to work with.

If you want to find out more about parallel charging and the benefits and limitations, here are some good sources for further reading: How-To: Parallel Charging - TJinTech

About parallel charging of Lixx / PB packs. - RC Groups

 

[irv_usc]

for multiple cells these chargers generally come with balancing circuits. you can build yourself a balance charger using the included leads.

btw i have a thunder AC6, which appears to be the same thing as a turnigy 6, except it has it's own built in power supply. if the supply goes out i can still power it using a laptop power brick.

 

[pae77]

for multiple cells these chargers generally come with balancing circuits. you can build yourself a balance charger using the included leads.

Only required if charging in series. Not needed for parallel charging multiple individual Li-ion cells (as opposed to packs). The Accucell 6 unfortunately doesn't come with balancing leads although it has the ports and circuitry for them.

btw i have a thunder AC6, which appears to be the same thing as a turnigy 6, except it has it's own built in power supply. if the supply goes out i can still power it using a laptop power brick.

 

[digitor]

No, you are not wrong. . . it's still a charger with only one independent channel.

The Accucell 6 has an inbuilt 6 cell balancer - 10 packs of leads with matching JST-XH connectors are available for a few dollars from the same popular online vendor that sells the majority of these chargers. Most R/C LiPo cells come with them already attached, so they plug straight into the charger without needing any other leads.

Cheers

 

[ronkar]

I use a flat disk of copper sandwiched between two neodymium magnets, and attach the alligator clips to the copper.

The disk was flattened with the help of a file and sandpaper.

Hint. Pre-1982 pennies are copper. 1982's could be either copper or zinc, and later dates are all zinc.

 

[KiwiMark]

If you get 100 of the 1mm x 6mm magnets from dealextreme then you have enough to use several between each cell to connect them, then you can use alligator clips or anything else that will attach to magnets on the end of each balance lead. Just have enough magnets between each cell and you can get your balance lead in there.

 

[hank]

OK, looking back at your picture

-- you're using LiPo setting (to get 4.2v), set at 0.2A, charging a Li-ion cell (is that a 14500 in the first picture? what capacity?)
-- the number on the screen in the lower right corner you say is "pushed ... so far" -- the manual says it's "charged capacity" but your description makes more sense since it counts up from zero. Is it actually measuring something at the battery?

My Accucell-6 just arrived. I'm starting with Li-Ion setting (4.1v), 0.1A (what, me hurry?) -- charging a new AW 18650 (2200 mah) that came at 3.93volts from a US reseller. I had run it down to 3.86v before I started charging.

After 30 minutes, it's showing 3.89 volts and a "00053" in the capacity corner.

 

[pae77]

OK, looking back at your picture

-- you're using LiPo setting (to get 4.2v), set at 0.2A, charging a Li-ion cell (is that a 14500 in the first picture? what capacity?) It's a 14500, actual (not stated) capacity is about 600 mAh. I did not set it a 0.2A. It's at 0.2A because it's in the CV stage of the cycle and the charge current is gradually declining to 1/10th of the initial charge rate (which in this case was 0.3A (or 300 mA).

-- the number on the screen in the lower right corner you say is "pushed ... so far" -- the manual says it's "charged capacity" but your description makes more sense since it counts up from zero. Is it actually measuring something at the battery?
No, it is only telling you how many mA's the charger has pushed into the battery. However, there is some overhead due to inefficiency and resistance and such so the actual amount of mA that the battery receives is something less than the number shown. But it still gives you a good idea of approximately how much charge the battery has received.

My Accucell-6 just arrived. I'm starting with Li-Ion setting (4.1v), 0.1A (what, me hurry?) -- charging a new AW 18650 (2200 mah) that came at 3.93volts from a US reseller. I had run it down to 3.86v before I started charging.

You should use the LiPo setting (and 1S) to get a voltage of 4.2. You also need to use a much higher charge current for an 18650. You should use at least .6 mA (600 mA) and you can safely go as high as 1C or in the case of your new AW 2.2A. It will take days to charge at .1A and there is no point is using such a low charge rate. .6 is actually plenty low, imo.

After 30 minutes, it's showing 3.89 volts and a "00053" in the capacity corner.

You are still in the CC part of the cycle. The current will stay at whatever you set it until the voltage hits 4.2 (if you use the proper LiPo setting) and then the current will start to gradually decrease until it has hit 1/10 of the initial charge rate and charged for a while at that rate.

Don't be afraid of using the LiPo setting to get a displayed voltage of 4.2. Even using that setting, your battery is going in all likelihood to come off the charger with a voltage a bit lower than 4.2V, probably something like 4.15-4.18 (although it could easily be even lower) which is just perfect, imo. A Trustfire red/black 2400 mAh 18650 just came off my Accucell 6 this morning at 4.16 V which is perfectly normal and appropriate, imo.

 

[hank]

Ah, that's helpful. I interrupted and set it up to 0.6A, and am showing 4.04v and climbing.

I'm expecting to charge my batteries often, and have been looking at this advice:
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

" better to charge lithium-ion battery at a slower charge rate .... A 0.5C charge and discharge would further improve this rating. ... If you have a spare lithium-ion battery, use one to the fullest and keep the other cool by placing it in the refrigerator. Do not freeze the battery. For best results, store the battery at 40% state-of-charge."
The do-and-don't list says "40% state-of-charge reads 3.75-3.80V/cell at open terminal."
__________________
"Oh, honey, I'll be cleaning out the stuff in the back of the refrigerator this week, I need to make a little some room for, er, other things ..."

 

[pae77]

.5C as recommended by BU is fine and there is nothing wrong with that, however, note that .5C of your 2200 mAh battery would be 1.1A which is almost twice the .6A I recommended earlier above. Imo, any charge rate between about .25C and .5C is good for getting extended life from your cells. But for Li-ion, I usually like to charge even a little more gently than .5 C. It's just my preference. You can, of course, choose any charge rate you like as long as you stick within the recommended guidelines. That's part of the appeal of these hobby chargers. You can select the rate you think will be best for your particular circumstances.

Also, note that the Accucell 6 has a convenient storage charge program that automatically charges (or discharges as may be necessary) to get Li-ion batteries to the optimal SOC to extend cell life when you are intending to store the cells unused for extended periods.

 

[45/70]

...... I interrupted and set it up to 0.6A, and am showing 4.04v and climbing.

I pretty much charge all of my Li-Ion cells at ~0.5C, anymore, unless I'm in a hurry.

Once upon a time (like 5 years ago), I read a theory that suggested that charging LiCo Li-Ion cells at too slow a rate produced similar results to trickle charging a fully charged cell (which is very bad). The idea was, as I remember, that when the charge rate approached the rate of self discharge, there was a risk of the plating out of metallic lithium on the anode of the cell. Therefore, very slow rates of charge such as less than 0.1C, were to be avoided. I never see this anymore, so it could be that the chemical composition has changed over the years, or something else has changed, and this no longer applies. At any rate, I just go with 0.5C for all chemistry of Li-Ion cells.

One thing to remember, is that very little to no heat is generated in the Li-Ion charging process, it is something like 99% efficient, so heat isn't much of an issue, as it is when charging NiCd/NiMH cells. Higher rates of charge have little disadvantage to slower rates, if any. Older Li-Ion cells would be the exception, but even they don't heat up much at a 0.5C rate.

Dave

 

[pae77]

I should just mention that the primary reason why I usually charge Li-ions at .25 to .5 C is because I find I usually manage to get a little more charge into the cells by charging them slower (as compared to charging at about 1C), and it really doesn't take very much longer than charging at a higher rate, so there is no real disadvantage to it that I am aware of.

 

[KiwiMark]

For a 2200mAh cell I'd usually look at somewhere up to 1/2 C - so as much as 1.1A, I'd probably set the charger to 1A and call that good.

The accucell will charge until the amps drop to 1/10 the amount you set, so charging at 1A will mean it charges at 1A until the voltage hits 4.2V then it will reduce the charging current while the voltage stays at 4.2V until the current has dropped to 0.1A. If you want to get more into the cell then you can just charge it again once it has finished - if you select 0.1V then it will charge the cell until the amps drop to 0.01A, the cell will be as charged as it can be without being over charged. I wouldn't bother with this though, you really wont get much more into the cell and it will take more time.

 

[45/70]

Yeah, the biggest difference in how fully charged the cells end up, seems to be backing down in the range from 1C to 0.5C. Below that, the cells will still receive a fuller charge at lower currents, but it becomes a matter of diminishing returns.

Dave

 

[Quest4fire]

[QUOTE=pae77;3553212 Btw, one more photo, this one of the inside of the Accucell 6 I took while I had it open to lube the fan:

After reading post on problematic fans on the Accucell-6 (I received mine in the mail the other day!) I opened the case and put a tiny drop of Breakfree (Cleaner/Lubricant/Protection) penetrating oil on the shaft. So far it run whisper-quiet.

 

[pae77]

Yes, lubing the fan is a very good idea. I'm sure there are many good products that can be used. Fwimbw, I used a product called "Tuf Glide" that comes with a needle applicator and goes on as a liquid but then dries leaving behind a micro bonding dry lubricant. Seemed to work well. I think if one keeps the fan's shaft appropriately lubricated, it will run quieter and be likely to last longer.

 

[dizhu]

I just got one and tried to charge my depleted IMR 26500. The screen shows voltage too low and refuse to charge. Only I change to LiFe mode and it starts charging. But that only give me 3.6 charged. Any suggestion?

 

[hellokitty[hk]]

Has anyone tried to calibrate the volt-meter to -.15v to trick the charger into charging the 4.35v Samsung ICD-18650-30a?

 

[KiwiMark]

I just got one and tried to charge my depleted IMR 26500. The screen shows voltage too low and refuse to charge. Only I change to LiFe mode and it starts charging. But that only give me 3.6 charged. Any suggestion?

So, once you have brought it up to 3.6V then what happens when you try to charge it with the LiPo or LiIo setting?