Originally Posted by Dr.Ben

Thanks guys.

Coupla things..............

First, the comment about the internal cell resistance may very well be the issue here, because we're dealing with pretty high internal resistance LiION cells which are in the 2S airborne radio battery. For a practical application of this function with this cell chemistry, the charger's algorithim out to take into count the higher internal resistance of these cells.

Per the manual, the charger IS supposed to charge OR discharge to target storage voltage.

I'll try decreasing the current for storage mode, as I was testing at close to a 1C discharge rate.

Fred,
Could you please paraphrase the description of the function as it's written in the manual? For the given adjustment, which way shall I adjust the percentage, up or down from 50%?

Thanks so much everyone.

Ben Minor

Discharge reduce gradually reduces the discharge current in order to keep the target voltage steady.

Example:
LiPo discharge: 2A, target voltage 3.0V (1 cell)
Discharge Reduce: ON, 20%
Discharging will commence at 2A. Once 3.0V is hit, the charger will start dropping the discharge amperage in order to keep the 3.0V from dropping any further. It will continue to do so until it hits 400mA (20% of 2000mA), then cease discharging.

Pretty cool, eh?

Yes, very. Thanks for the detailed and clear response.

Most people will just want it "in the ballpark" of the right voltage range for storage, that is not full and not empty, but in between , and favor speed over accurate storage voltage. I would tend to agree, as I see the exact voltage for storage as non-critical, but it is excellent to understand that this feature exists and how it works.

Cheers,
David

Thanks to everyone here.

As I told David in an email to him, dropping the d/c current is the ticket if you have higher internal resistance cells like LiION's. At 1/2 d/c rate in storage mode, the program is working exactly right.

I'll play with the current reduce next.

I will say this. A close to 4.6K response thread is one hell of a knowledge base for product support.

Ben Minor

It seems like this is something which could be fixed in a future firmware update because if the discharge current is tailed off towards the end of discharge, the charger could monitor any rise in cell voltage and continue the discharge to suit. In the same way the current is tailed off during the CV phase of the charge.

One for the firmware feature wishlist?

Dear Junsi,

I would like to propose adding update date to the User's Manual.

-mikko

ps.
I did receive a brand new and shiny 208B just recently. Quite impressed! I also did the SW upgrade to 3.11a and it also worked without any hick-ups. The steps I did for the upgrade were:

- install Junsi USB driver (Only need to do this once and it stays good for the forthcoming upgrades, as well unless new revisions to the driver become available.)


- Download the most recent beta from page 309 in this thread.
- Start the upgrader.exe (from the CD or for the most recent: http://www.hillrc.com/UploadFiles/upgrader.rar. Current version is dated 13.4.2009)
- power iCharger 208B by a (in my case, 2s / 5000mAh LiPo) battery to ensure stable power during the upgrade.
- connect the charger to PC by the supplied USB cable
--> Upgrader will show the device serial number and current FW version.
- Select the new firmware file in upgrader user interface. (iC208B_V311a.bin)
- Hit "Update..." button.
--> a progress bar will appear on the PC screen. Charger will stay in what ever screen it was.
--> once the progress bar is ready, the charger will reboot, and quickly show the new version (as it does every time you start the charger). The upgrader will prompt a message box saying "update successful" or something like that.



-mikko

Originally Posted by natterjak

It seems like this is something which could be fixed in a future firmware update because if the discharge current is tailed off towards the end of discharge, the charger could monitor any rise in cell voltage and continue the discharge to suit. In the same way the current is tailed off during the CV phase of the charge.

One for the firmware feature wishlist?

I am not 100% if I understood your request. Sounds to me though, that you are just eye-witnessing the DISCHARGE REDUCE feature in action. What is your setting for this parameter?

Are you actually requesting that the (LiXx) discharge would do the last pieces of discharge through the balance port in order to reach precise same level for each cell? Like balancing discharge? Not being a battery expert, I am not sure how necessary this is - unless the battery pack has seriously different cells and therefore the discharge (and any flying, as well) would result in one or more cells dropping dangerously low before the whole pack voltage gives any indication of being low.

-mikko

I have had my iCharger 208B for approx. two months now and it is very likely that mine has seen more usage than most do in a year.

I have updated the firmware several times without and issues and have really enjoyed the improvement which myself and others have suggested and Junsi incorporated.

A little over a month ago I ran into the Connection Break Error and re flashing the Firmware with the same Rev. 3.11 I was running at the time fixed the problem.

The following I post with some reservations.

Yesterday after a couple of normal charging sessions my charger decided it would play dead. It would power up normally but would flash the display then reboot if any charge was started or even if I merely pushed and held the Stop button as when going to the Vi / Vo / Int and Ext Temp screen.

I tried doing a re flash of memory and all I got was the charger acting the same and after about 5 cycles Device Not Found Error.

I noticed that Program Select was misspelled and contacted David at Progressive RC and was informed that he had not heard of this issue as yet. David contacted the manufacture and this morning I had a PM with a possible solution to try. I am glad to report that my 208B is now functioning again.

Thanks David and the technicians at Jun-si

Charles

Charles, please don't keep the solution to yourself. Do tell us what the fix is....

chewy

I would prefer to wait and let David or Junsi post such if they deem it suitable.

To the best of my knowledge the fix can not cause any additional or other issues but then I really do not know for sure. I will say it was extremely simple and fast.


Charles

Let's not share this widely, it is somewhat dangerous as a form of "hard boot" which can possibly cause further firmware data corruption. In Charles' case it was apparent that the firmware was slightly awry from the last update and this was the best and last option prior to a replacement unit. This is the first firmware corruption I've seen, unprecedented and highly unlikely. If anyone should need service or support, please do not hesitate to ask, but this is not a solution to be applied prior to thorough troubleshooting.

Glad you are back up and running Charles! Now please continue to flog the hell out of that charger .

Regards,
David

Maybe this "hard boot" can reset my iCharger 106B, or does it only work with the 208B?
Please send me a PM with instructions, if this is possible.
thanks

PM sent - I'm always happy to help any way I possibly can.

- David

me have i charger 106B+, testing a rhino lipo 2s1p 1750mAh 25C, with DMM it shows 4.17v/cell, but my icharger show 4.20v/cell, so which is the one that correct? using 3.11 firmware...

eszaqsc,

How accurate is your dmm? Is it a calibrated one or one of those "cheap" models? Once you have the answer to that, then you have a better idea which to trust. The 106B+ that I got had the voltage of 5 cells checked to 4.20V after charging with a friend's industrial strength calibrated meter, so I know which to trust.

chewy

The difference between 4.17 and 4.20 per cell is approx. 3% state of charge and is not worth being concerned with IMO. In fact if the 4.17 is correct it merely means it is being a bit easier on your LiPolys.

Which one is correct is impossible to say without knowing how accurate your DMM is and when it was last calibrated and how accurately.

Have you went back and checked the cell voltage using your DMM and the charger after the LiPoly has had a few hours to settle?


Charles