Feb 04, 2013, 11:53 AM
Registered User
USA
Joined Jan 2002
5,469 Posts
Quote:
 Originally Posted by mrforsyth No, the statement applies exclusively to single packs. It was meant to illustrate that % charge cannot be accurate due to physics involved. e.g. - charge state based on voltage is only reasonably accurate in static (no load) condition. Since charging is a loaded condition, % charge will be a rough estimate, much in the same way that voltage during discharge tells little about remaining capacity. Regards, Mark
But as I mentioned earlier, if the percentage displayed in the UI to the user is simply based on a lookup table of the voltage then there s a 1:1 relationship between voltage and percentage.
 Feb 04, 2013, 12:04 PM Registered User So. Cal. Joined Oct 2004 9,580 Posts True, but the lookup table is based upon resting voltage, whereas a battery that is being charged is anything but resting. As such, traditional lookup tables are useless and are greatly exacerbated by charge rate and cell internal resistance, as stated previously. Thus, no 1:1 ratio exists unless the charger periodically stops charging for a good amount of time to allow the cell to recover to resting voltage. This must be done throughout the charge cycle and can wreak all sorts of havoc if not implemented properly.
 Feb 04, 2013, 12:16 PM Southern Pride Haralson County GA. USA Joined Oct 2004 35,074 Posts Percentage Fuel Table I have linked to numerious times is from a PL8 and is accuarte during charge. http://www.rcgroups.com/forums/attac...5&d=1299261126 IMO to many make to big of a deal about such. 4.2 is 100% 4.1 is 90% 3.7 is 0% useable remaining but is fime for storage. Guess I am old ,set in my ways and just can not understand why it matters if Fuel % is 45,65, 70 % or what. FYI As mentioned Fuel % is not accuarte for all LIPoloy. Different IR,temperature ,real remaining capacity etc. Percentage displayed in the first 10 min. of a 1C charge should just be ignored unless it is les than 10% in which case reduce your flight times. Charles
Feb 04, 2013, 12:35 PM
Registered User
USA
Joined Jan 2002
5,469 Posts
Quote:
 Originally Posted by mrforsyth True, but the lookup table is based upon resting voltage, whereas a battery that is being charged is anything but resting. As such, traditional lookup tables are useless and are greatly exacerbated by charge rate and cell internal resistance, as stated previously. Thus, no 1:1 ratio exists unless the charger periodically stops charging for a good amount of time to allow the cell to recover to resting voltage. This must be done throughout the charge cycle and can wreak all sorts of havoc if not implemented properly.
What level of accuracy are you expecting? If charge rate and internal resistance are the only variables then additional calculations could be easily performed using these two values to still provide a reasonably accurate value.
Feb 04, 2013, 12:51 PM
Registered User
So. Cal.
Joined Oct 2004
9,580 Posts
Quote:
 Originally Posted by everydayflyer Guess I am old ,set in my ways and just can not understand why it matters if Fuel % is 45,65, 70 % or what.
Agreed.

Further, implementing the estimated fuel % on the FMA chargers is much easier than iChargers due to the fact that FMA has periodic rest periods throughout the charge cycle to allow for semi-recovered voltage. These short rest periods also serve as the basis for reported IR, as you know.
Feb 05, 2013, 12:28 AM
Registered User
Joined Jul 2008
4 Posts
Quote:
 Originally Posted by JohnathanSwift Anyone?
i have done it. No problem.
 Feb 05, 2013, 07:10 AM Suspended Account Greenland Joined Mar 2012 9,069 Posts O.k. That's one. Others?
 Feb 05, 2013, 09:34 AM Registered User United States, IL, Momence Joined Nov 2003 95 Posts I personally remove my packs from the model and test their voltage with a handheld meter that offers a suggested % of capacity left. This is a very valuable tool for adjusting my timer for each model. As the packs age, weather changes, or model adjustments are made I have a reference to help me set my flight times to the proper duration. Also, I may adjust my flight aggression and demand on the packs based on this feedback. Would it not be helpful to simply plug the pack into the charger and see what the consumption was on the pack and leave the handheld meter on the workbench, thus eliminating one more connection and reading per pack used? I like the idea of a % of charge, even if it is a rough value and not scientific lab reference quality. Now, what about those SD cards?
Feb 05, 2013, 09:51 AM
Registered User
Sweden, Sundsvall
Joined Aug 2011
65 Posts
Quote:
 Originally Posted by TylerL Now, what about those SD cards?
I use a 4gb Sandisk SDHC class 10 in my 4010duo, it works for me.
Feb 05, 2013, 09:55 AM
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Greenland
Joined Mar 2012
9,069 Posts
Quote:
 Originally Posted by FeffeSvl I use a 4gb Sandisk SDHC class 10 in my 4010duo, it works for me.
Feb 05, 2013, 10:11 AM
Registered User
Sweden, Sundsvall
Joined Aug 2011
65 Posts
Quote:
 Originally Posted by JohnathanSwift Have you loaded v 2.02?

No sorry, not yet. I was actually waiting for you to test it first But seriously, I have loaded beta 4 and one earlier before that and it worked.
Feb 05, 2013, 10:39 AM
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Greenland
Joined Mar 2012
9,069 Posts
Quote:
 Originally Posted by FeffeSvl No sorry, not yet. I was actually waiting for you to test it first But seriously, I have loaded beta 4 and one earlier before that and it worked.
Hee, haw!
 Feb 05, 2013, 10:48 AM Registered User United States, IL, Momence Joined Nov 2003 95 Posts Those of you using an sd card, what is the real world use/value of utilizing this feature? Next, what is a desirable sd card capacity? I see some are using a 4G. Any regrets on this size? More/less? I find the manual and online discussion/resources very vague in this area.
Feb 05, 2013, 12:08 PM
Registered User
Sweden, Sundsvall
Joined Aug 2011
65 Posts
Quote:
 Originally Posted by TylerL Those of you using an sd card, what is the real world use/value of utilizing this feature? Next, what is a desirable sd card capacity? I see some are using a 4G. Any regrets on this size? More/less? I find the manual and online discussion/resources very vague in this area.
Well, the only point with the memory card is if you want to log the charging. I suppose it can also be good to have a log file to send to Junsi if necessary.

I don't know about the size, just used what I had on hand. Loaded 2.02 BTW, worked fine.
Feb 05, 2013, 12:28 PM
Registered User
USA
Joined Jan 2002
5,469 Posts
Quote:
 Originally Posted by mrforsyth Thus, no 1:1 ratio exists unless the charger periodically stops charging for a good amount of time to allow the cell to recover to resting voltage. This must be done throughout the charge cycle and can wreak all sorts of havoc if not implemented properly.
Quote:
 Originally Posted by mrforsyth Further, implementing the estimated fuel % on the FMA chargers is much easier than iChargers due to the fact that FMA has periodic rest periods throughout the charge cycle to allow for semi-recovered voltage.
Have you measured the accuracy difference between fully-recovered and semi-recovered?