aghost

My Feedback: (13)

Flyfast1: Just in case it makes a difference to you regarding the 8FG -There is a fairly simple way to put the flaps on a 3 position switch and use that throttle servo slow function to slow the flap servos instead. I forget which thread had the method, but i am using that method on several planes.

Brian

Flyfast1

My Feedback: (1)

Thanks Brian, I was not aware of that.

-Ed B.

geefish1

Does anyone that uses the 8FG S, charge their NiMh battery with a field charger at more than the 170mah wall charger rate? Like at 1C.

DaddySam

My Feedback: (9)

I use the standard "fast charge" on my CellPro Multi4, and my Powerlab 8, which is 1 amp then trickle. I've also created a slower charge in the charger for times I'm not in a hurry. The NiMh should be able to handle a fast charge without problems. 1 amp is just over C/2 (1700 mah/1000mah) and I've read that NiMH should tolerate 1C charges.
Sam

BuschBarber

My Feedback: (2)

While these particular NiMh batteries may handle a Fast Charge, many NiMh batteries do not tolerate a Fast Charge and will Overheat or False Peak and fool the charger into thinking the batteries are charged, when they are not. I have had many problems with NiMh batteries over the years and found that they prefer a slow charge, such as what you get from a Wall Charger. This is true even when using chargers like the Triton, that are designed for NiMh. I have LiPo Only versions of the FMA 4S and 10S and I find them superb chargers. I am sure the versions that handle Multi Chemistry would also produce excellent results.

geefish1

It sounds like I probably will use the wall charger mostf the time unless I have a need to recharge at the field. Then I will use my cellpro Lab 8.

Thanks

TimBle

I have never needed to recharge at the field. The 1700mA.hr NiMH lasts nearly 10 hours of continuous use and that s more than enough for a weekends flying without recharging. I simply charge it Friday night.
I carry a 2500mA.hr ZIppy Flight Max 5C Rx 6.6V LiFePO4 in my transmitter case asa back up pack. Its form factor is similar to the supplied Futaba TX battery.
With v4.1 of the Tx software I can adjust the alarm to 6.4V through the Alarm menu.

geefish1

Will the battery size fit in the radio case? Is the connector plug compatible?

TimBle

Yes would you like some pictures?

geefish1

Thanks, that would be fine.

TimBle

zippy flightmax 2500 6.6V5C LiFePO4 comapred to Futaba HT6F1700BNiMH

geefish1

Excellent! I will order one from HK with my next order of Turnigy Nano Tech lipos. I fly 6 electric planes.

pilotpete2

Thanks for posting those pics!
I just looked at the listing for that pack. Only $9.48 from the US warehouse[8D] I may just give one of those a try.
TimBle, With the LVW set to 6.4V, have you let it continue to run after the warning goes off to see how long it the 8FG will run until the radio hits the voltage where it does a shutdown?
Pete

BuschBarber

My Feedback: (2)

While the transmitter will most likely still operate when the Tx battery voltage drops below 6.4v, you risk damaging a LiPo pack when you discharge it below 3v/cell. When you consider how many hours you can operate a Tx with a LiPo Tx battery, and given how long a LiPo pack holds it's charge when not in use, is it worth the risk to draw down your LiPo Tx pack below the 6.4v Warning.

I am just suggesting that you may compromise the life and performance of the LiPo pack.

pilotpete2

Hi Rich,
No, this is in regard to the LiFePo4 pack, which would be sitting at about 6.6V (nominal) for almost the entire usable capacity. My only concern with using one of these pack is, would there be ample time to land if the LVW were to go off. Flying to LVW is not something I normally do
Pete

BuschBarber

My Feedback: (2)

Sorry for the misunderstanding. That is a very good question. I use LiFe Rx packs. I recharge them every couple of days as it only takes 15min on my FMA 10S charger. They usually read 65%. I have not tried one in my Tx, but having a LV warning sound, that goes off at a voltage appropriate for the type of battery your are using, would certainly help in determining when the LiFe Tx battery starts to drop. It would also nice if there were Telemetry in the aircraft for at least the Rx battery, as well.

pilotpete2

Rich,
I use the A123 packs in all my gas and glow models for rx, servos and ignition (IBEC). I just top them off before the first flight of the day with the FMA Multi4. If I use a total of 40% from a pack in a flying day, that's a lot[8D]
I bring a bunch of models with me, and my thermal sailplanes (3S Lipo) can take a big chunk of time out of a flying day, so the noisy ones only get a couple of flights each.
For the transmitter, I can go either chemistry, since the 8FG is based on 6 cell Nimh it is totally compatible with 2S Lipo, but is also good with the LiFe packs, which I like because you can leave them fully charged, unlike the Lipo that doesn't do as well when left fully charged for any length of time.
Pete

BuschBarber

My Feedback: (2)

I have one gasser H9 P47-150. I have a Royal P26 Peashooter running on 10S LiPo, an H9 Carden Yak54 running on 12S LiPo, an Aeroworks 29% Katana running on 10S LiPo, and an Eflite Extra 300 running on 5S LiPo. Except for the Eflite Extra 300, all the other aircraft have 2cell LiFe Rx packs. I have a bunch of other foamie electrics, as well.

geefish1

I just recently bought a 9.9 v LiFe battery for my 7C. The voltage holds for a long time. But I have heard that they drop suddenly which is not good for a transmitter. Does the voltage go down to 9.8, 9.7 etc. Or does it just go dead? By the way how do I add this thread to My Forums?

BuschBarber

My Feedback: (2)

I believe the voltage of an A123/LiFe battery drops to 3.3v/cell and stays there until it is fully discharged. At the end, there is a sharp drop. I have never let mine drop to that point so perhaps someone else has.

http://www.electrodynam.com/rc/EDR-207/index.shtml

You may have to substitute the FG website address for the xxxxx in the address below.

http://www.flyinggiants.com/forums/s...ad.php?t=17411

http://www.bphobbies.com/pdf/a123/a1...ngbrochure.pdf
http://www.bphobbies.com/view.asp?id=V052084

TimBle

Pete and Busch

Since its a LiFePO4 pack, for the first 20 charges I don't discharge it below 3.2V per cell. This is not really to form them but with my Hyperion packs I find that they improve in performance over this period. I now get around 1850mAhr from a 1700 LiFePO4. No doubt this will drop back to nominal capacity as they get older but I find I have yet to fly a LiFePO4 flat. I always recharge them after a days flying.

I did sacrifice one pack (Hyperion) to see what happens if you discharge to 2.5V per cell. No fireworks, they simply do not balance very well after 30 ish cycles. So the manufacturer warnings are grounded in truth.

These Zippy packs just arrived in the week so I've charged all three of them at 0.8C for the first charge. They recommend to never exceed 1C charge rate and I certainly do not intend to exceed that.

So once I've "run in" the Zippy's, I'll record the flying time before the drop off point approaches. With all the LiFePO4's I have its typically around 6.3 to 6.2V depending on your appetite for excitement.

One of the packs is for the 8FG, the other two are for my BH FW 190 (with MVVS 30cc) and GW Racer Edge 540 30cc

TimBle

Ihave one of those Hyperion flat TX pack for Futaba in my 6EX. Its drop off point is 9.2V whichis justover 3.0Vper cellIstop flying when it reaches 9.5V.By thenI've had nearly twice the flying on my slopies than if Ihad used the original 800mA.hr NiCad.

pilotpete2

With the flying season pretty much done around here, the 8FG will mostly be getting use setting up some new models and flying a Slow Stick around the property.
I took a 2S 1100mAh A123 pack from a model that has been winterized. It is a gentle friction fit in the battery compartment. I just topped it off and set the LVW to 6.4V. It will be interesting to see what actual percentage of the capacity it takes if I run it to LVW, and how many hours on the "Hobbs" that will take.
Pete

geefish1

Qustion for you guys. On the 8FG S if you are flying one model and make some trim adjustments are they automatically saved to the Tx? And then how do you transfer those changes to the SD card? I tried copying the model with changes and it created the model name with a 1 after it.

landeck

My Feedback: (1)

Yes, the trim changes are saved for each model. With respect to copying changes to the SD card, first delele the old model on the SD card then copy the model again from main memory.

Bruce