No. from the superfast HobbyKing ;-)
Guess I will get a new one in the fall...

Originally Posted by AlPackin

Hi, I have an iCharger 206B with a XT60 Paraboard and a P350 power supply. I've been charging 2200mah LIPO's for about three weeks now. Sometimes one at 2A, up to my five at 10A. I was just charging four at 8A and about 20 minutes into a normal charge cycle it started beeping. It says that the battery is "overvoltage"

I disconnected all of them and reconnected one at a time ... same thing "overvoltage".

I even connected the fifth one I charged the other day .... same thing "overvoltage"

It smelled funny when I turned it on ... must have crapped out?

Hello AlPackin,

Please press STOP for 3 seconds to monitor the voltage of each cell to see if there is any difference between the displayed voltage and measured voltage? If different, please check if the battery balance port, the wire from balance board to the charger, and the balance board are damaged or some lines are disconnected. Easily, you can use DMM to ensure each cell voltage coming to the charger. If the balance board or balance wire has been burnt, please change one. (Please also check another file “bal err” on the first post.)

Junsi

Originally Posted by junsi

Hello AlPackin,

Please press STOP for 3 seconds to monitor the voltage of each cell to see if there is any difference between the displayed voltage and measured voltage? If different, please check if the battery balance port, the wire from balance board to the charger, and the balance board are damaged or some lines are disconnected. Easily, you can use DMM to ensure each cell voltage coming to the charger. If the balance board or balance wire has been burnt, please change one. (Please also check another file “Attachment 4101393” on the first post.)

Junsi

I connected the balance plug directly to the charger and its working fine. The Paraboard must have crapped out

That's a relief. At least I can still charge them one at a time.

I'm not an expert on batteries yet and one of the hardest things for a new RC pilot is to figure out a way to charge 5 batteries quickly so he can spend a few minutes flying and not most of the day waiting on batteries to charge. My original idea was to buy 5 cheap Turnigy lipo chargers at 11.44 a pop, not bad for 2 and 3 cell Lipos. http://www.hobbyking.com/hobbyking/s...idProduct=8247

I have 1 and it works great for the money, its nothing fancy, has no digital read outs of any kind and only does 2 and 3 cell Lipos and has auto shutoff. You can get it in AC or DC. It is slow though and takes an hour and a half to charge my Blade SR 1000mah Lipo's. With 5 batteries I'd get about 40 minutes of flying time for every hour and a half of charging for 57.20 plus shipping and tax.

This is the ultimate but way more expensive and what I want to eventually do as I move into larger Helis requiring 6 cell batteries. This is awesome. Be sure and check out the You Tube Video half way down the page.
http://www.progressiverc.com/paralle...t-xh-xt60.html

From the reviews tab on the HobbyKing $11 charger:
" one cell was 4,27V the cell at the center was 4,18V or 4,19V and the other 4,19V."

Not so good for your batteries. I had a cheap four button imax b6 clone, and wasted my $ as the voltages were so out it wore out my LiPos early. I can now only use it to charge NiMh and Pb, and have replaced it with a 208b. Expensive but should never need upgrading.

Originally Posted by Patrik J

No. from the superfast HobbyKing ;-)
Guess I will get a new one in the fall...

You could try to negotiate a refund from HK, and order a new one in the meantime. This way, you only have to wait for the money, but have a charger.

Hi Junsi,

I have recently learned about a new fast charge method for LiPos (and other Lixx packs).
This method is built up on the theory, that a cell can be divided into the charge storage (galvanic cell), and a resistor (the inner resistance).

When the cell is charged, the total cell voltage consists of both the voltage of the galvanic cell (charge storage), and the voltage drop across the resistor. Important for the CV phase of the charge is only the voltage of the galvanic cell, but not the one of the resistor. But normal chargers can only take the sum of both into account during a charge, thus reducing the charge current and terminating the charge process too early. One can easily see this, as most packs have a sudden voltage drop when the charger stops charging.

This new method makes little pauses during the charge without current. Then the voltage is checked. Without current, we do not have a voltage drop across the resistor, hence the charger only sees the actually important voltage of the calvanic cell.

During charge, the total cell voltage is allowed to go up to 4.35V (LiPo), but only, if the "resting voltage" (without current) of the cell stays at or below 4.20V.
It is said, that this considerably reduces charge time, while not compromising the batterys cycle life.

I think that this might be an interesting feature to add to the charger. I would gladly do the field testing work.

Cheers,

Julez

Originally Posted by Julez

You could try to negotiate a refund from HK, and order a new one in the meantime. This way, you only have to wait for the money, but have a charger.

Junsi will help me with this one.
Great support from him, have another charger I can use while I wait.

Originally Posted by Julez

During charge, the total cell voltage is allowed to go up to 4.35V (LiPo), but only, if the "resting voltage" (without current) of the cell stays at or below 4.20V.

It is said, that this considerably reduces charge time, while not compromising the batterys cycle life.

I think that this might be an interesting feature to add to the charger. I would gladly do the field testing work.

Cheers,

Julez

IIRC didn't some NiCd chargers of the past do something like this -- Reflex Charging?

Also, wasn't there just big arguement suggesting not to fill up LiPo to the very top; does the existing method give us a bit od a pad towards this?

How about adding a Multi Phase charge curve/technique to the Pb's routine?

Julez, Quite a few chargers have been working that way for years now, perhaps it is why some are quicker than others for the same packs.

Hyperion, FMA and Maxpro all use a pause during charging to monitor the resting cell voltage. I know that the Hyperion 610 used to pause every 60s and the Maxpro X6 every 5s. The Bantam B6 used to do it every 30s but only in the CV-phase.

I cannot say for sure how high they allow the voltage to go while current is flowing, but they certainly cut off the charge current to do a cell check.

IIRC didn't some NiCd chargers of the past do something like this -- Reflex Charging?

While Reflex charging has a pause, the major distinctive feature is a short but strong discharge pulse after it.

Also, wasn't there just big arguement suggesting not to fill up LiPo to the very top; does the existing method give us a bit od a pad towards this?

Well, not filling it to the top is beneficial, but that should not keep us from doing this in a fast manner.
As long as the resting voltage is kept within limits, Lipos do not seem to mind if the voltage during the charge process is a tad higher.

Julez, Quite a few chargers have been working that way for years now, perhaps it is why some are quicker than others for the same packs.

Cool! This seems definitely to be a concept worth tracking. I learned of it when reading about the Pulsar chargers, they call this feature "Fastmod".

Here is a paper about this. It gets interesting after page 5:
http://www.st.com/stonline/books/pdf/docs/4391.pdf

That paper is quite old (1998) as are others I found about pulse charging LiXx cells, so I would be careful about applying their conclusions to the current generation of cells used for RC, which clearly have very different characteristics. Using conventionaly CCCV charging contemporary LiPo cells charge from 80% discharged in 50 to 70 minutes, not the 2.5 hours mentioned in that paper. To me that says something about the changes (advances) in chemistry and anode composition.

So I agree that there may be something gained by adopting a periodic pause to check the resting cell voltages, I would be against changing to any significantly more aggressive like the reflex-style method mentioned in some references.

Originally Posted by kgfly

that paper is quite old (1998) as are others i found about pulse charging lixx cells, so i would be careful about applying their conclusions to the current generation of cells used for rc, which clearly have very different characteristics. Using conventionaly cccv charging contemporary lipo cells charge from 80% discharged in 50 to 70 minutes, not the 2.5 hours mentioned in that paper. To me that says something about the changes (advances) in chemistry and anode composition.

So i agree that there may be something gained by adopting a periodic pause to check the resting cell voltages, i would be against changing to any significantly more aggressive like the reflex-style method mentioned in some references.

q.e.d.

Originally Posted by Julez

Here is a paper about this. It gets interesting after page 5:

I'm sorry, but we don't accept any documents unless they have been funded by non-profit organizations and have appeared in at least 3 peer-reviewed journals.

I doubt their claims that conventional LiXX charging reaches the CV phase after 30 minutes at 1C and needs 2.5 hours for a full charge, but I guess if you had a lot of resistance between you and the battery it could happen with dumber chargers. Still, I've never had a phone or laptop that took 2.5 hours for a full charge.

Back when the FMA CellPro 4S was new I recall claims that you could use very long charge leads with no ill effects, something like 16 feet. The reason why is that the charger would pause from time to time and use the -dV to compensate for line losses. With products like the FMA PL8 you can actually use Kelvin connections to allow for line loss compensation without having to pause the charging process, but I know it still pauses from time to time to evaluate the battery being charged and the power source.

To bring this back to the iChargers, I have no idea what they do, but I suspect "nothing" as we already know they have issues reading cell voltages because they don't compensate for the voltage drop of the wires.