RE: A123 Question
 

You should come up to the Deland Huckfest and hang out.

RE: A123 Question
 

For the naysayers......

One 12 minute flight and probably another 6 or 8 minutes of "on" time, warming it up and pre-flight (also dropped some expo and increased throws before my flight).

Battery #1 - Took 14 minutes to charge at .5amp and took 32Mah

RE: A123 Question
 

Tazmanian Devil maybe?

Sheesh...

RE: A123 Question
 

Cute little bugger though....

RE: A123 Question
 

Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.

RE: A123 Question
 

<span style="font-family: Comic Sans MS;"><span style="color: rgb(128, 0, 0);">I fly with an Hitec Aroura 9 with 7 and 9 channel optima receivers ... the receiver continually displayes the onboard battery voltage and you can set a low limitt and then the transmitter moduel beeps and flashes the red light to warn me that the on board battery is at or below the limit Ihav set in the transmitter. The transmitter also records the lowest and highest battery voltage for each flight.</span></span> But I have switched to LIFE 2500 MAH 2 cell Zippy Bateries from Hobby King about $9.00 each.

RE: A123 Question
 

+1....

RE: A123 Question
 

Yes, it automatically detects the LiFe batt over the Li-Po and goes into auto mode. It always reads 8.38V when the charge cycle is complete. During charging it is around 7 to 7.5v.
Battery "B" took 23Mah earlier but I got sidetracked and forgot to snap a photo. It also read 8.38v.

RE: A123 Question
 

Hmmmmm, seems strange to see any reading at any time higher than 7.2V or two LiFe cells!

RE: A123 Question
 

I manually set my LIFE settings at 6.6 and max cut-off at 7.2. I found the "Auto" functions on some chargers simply do not work correctly. I once overcharged to 8.4 on "Auto" and once I found out, I then discharged the pack and charged back up to LIFE 6.6 with a 7.2 cut-off. Now the charger goes up to 7.2 and charges the battery correctly.

I think the problem is that the charges cannot properly identify the difference and just catagorizes the batteries as LIxx even though they say they can correctly charge on "Auto" settings.

RE: A123 Question
 

I will look into it, thanks. When I check the battery voltage with a meter after charging (usually 15 or 20 minutes later when I am going over the plane), it is usually reads around the low 7 volts.

RE: A123 Question
 

Taz, c'mon up to Huckfest in Deland in November and hang out. You can meet Rich from WrongWay and he will talk the ears off an elephant about A123's

RE: A123 Question
 

RE: A123 Question
 

From the expert Iwouldnot use just any old charger. Only a charger that is rated for A123/ LiFe batterys <div style="text-align: center; margin: 0in 0in 0pt" align="center"><font size="3"><span style="color: black">http://www.hangtimes.com/a123_batter...iants_faq.htmlQ: Can I use my &lsquo;XYZ&rsquo; brand NiCad /NiMH charger or Wall Wart on LiFe?</span></font></div><div style="text-align: center; margin: 0in 0in 0pt" align="center"><font size="3"><span style="color: black">*</span></font></div><div style="text-align: center; margin: 0in 0in 0pt" align="center"><font size="3"><span style="color: black">No. Let me be specific&hellip; HELL NO! Here&rsquo;s what&rsquo;s going on.. LiFe&rsquo;s nominal voltage per cell is 3.3v. While the charge routine is similar to LiIon or LiPoly, the max allowable voltage under charge is lower than any other Lithium technology cell, usually about 3.6v; so using a standard LiIon or LiPoly charger will do damage. For you NiCad -NiMH guys, the entire charge sub-routine is different . As of now, there are a number of LiFe capable superchargers coming into the marketplace.. these will deal with &lsquo;em as well as the various other types of Lithium and NiCad/NiMH packs but assume my first answer of HELL NO applies until you review your chargers manual. If you not sure, contact the charger mfg or distributor. Don&rsquo;t let &lsquo;em blow smoke up your backside either. Get it in writing if it&rsquo;s not called out in the manual.</span></font></div>

RE: A123 Question
 

<div style="text-align: center; margin: 0in 0in 0pt" align="center"><font size="3"><span style="color: black">1. Non Balancing 'smart chargers' and the myth that A123's 'don't need balancing'.<span style="color: black">A close tofully charged pack, deeply discharged pack or out of balance packmay be easily mis-identified by a 'smart'charger WITH THE WRONG CELL COUNT. The results are usually always a ruined pack. If a qualitybalancing charger is used and correctly connected, the charger will see the individual cell voltages in the pack, correctly identify it's cell count and usually report on the individual cell voltages all the way through the charge routine. If 'smart' means stabbing a button and waiting for a green light... well; that mightnot be an appropriate charger for a critical application battery pack.</span></span></font></div>

RE: A123 Question
 

[quote]ORIGINAL: Taz_Hobbies


Thankfully this only happened to one pack of mine and so far so good. Someone told me that these batteries are very robust and can stand it, but not to let it happen again as it could damage it. I am concerned, but only time will tell. I will monitor the pack closely and see whether it holds up.

I did do a couple of discharges to bring it down to around 5-6 volts and then re-charge and balance and all seems ok. I am thinking about working the battery on the bench some as if in flight, then charging again on minimal charge.

RE: A123 Question
 

I wonder about balancing. If I set my charger to 1-2 amps and also to balance mode it seems to balance the batteries very quickly. Within about 10 minutes a pack is balanced. Is that normal? I am guessing that the packs are close and balancing may not take long.

Also, I am only pulling about 289-300 MAH out of four flights the last two times out to the field. That calculates out to around 75 mah per flight. Doesn't that seem low? From what everyone else was showing it should be more around 150-200 per flight. I tested this on two planes and both were running almost the same. The most mah I have drawn so far is around 100mah in a flight.

The last test I did was took both planes and flew them both four times each and both tested around 300 mah for all four flights. To me this is ridiculously good. At that rate on a 2500 mah pack I could safely fly 6 flights and not bat an eye to bother with charging. I would only be drawing around 400-600 mah for six flights.

I plan to test my 50cc before too long to see how much it uses. It would be nice if there was a slick way to bench test these A123 batteries. If we had something that could load the battery somewhat comparible to a plane in flight and then re-charge would sure make it easier to determine a baseline. There may be some tools to do that but nothing I am aware of. I suppose I get set a dummy setup up and use some servos on a receiver and emulate it to some degree.

RE: A123 Question
 

That seems like very VERY low consumption to me

RE: A123 Question
 

That was my take as well. I hope some more chime in on this one. I still think a solid bench test might be in order and maybe utilize some other testing tools to verify. So far even though I show that little consumption, I limit myself to four flights and then charge up again.

RE: A123 Question
 

Luchnia -

Pardon a rookie for "chiming in" - you didn't specify the plane, servos or flight times in your comment about low energy consumption. For example, I'm using a 2300 mah A123 battery in a 5 lb 11 oz U Can Do with Futaba S3152 digital servos (89 oz/in torque) that I fly aggressively - 8 minute flights. My average consumption is about 95 ma per flight. My 8 lb 10 oz Venus pattern plane equipped with the same battery and servos uses about 120 ma per 8-minute flight practicing the Sportsman pattern (very unaggressive flying).

Can you use these examples for a comparison?

Jack

RE: A123 Question
 

I am not sure of the exact weight of the planes, but one 30cc gasser has 200 oz Titanium Gear servo on rudder and the rest are digitals that run around 130-150 oz. Flight times are set at ten minutes and I fly the full ten the majority of the time. One NIMH battery for ignition and one A123 2500MAH on receiver. The other plane has Hitec digitals all around. I think they are 5945MG or something along those lines.

I use two servos on elevators, two on ailerons, one on rudder, and one on throttle. I use opto kills for ignitions. My flying is not overly aggressive, yet I will do some snaps, and some other wild stuff. I will do knife edges, loops, rolls, etc., some light duty hovering for a very short time as I am not experienced with that yet.

RE: A123 Question
 

It appears my numbers are not all that far off, but still seem of somewhat. I will put much more focus into it now. I have not been really pulling hard details, however now I am really curious ;)

RE: A123 Question
 

20 cc profile 15kg digitals = 150 to 200 mah per ten min flight

26cc 1/4 scale pitts 15kg digitals = 150 to 200 mah per ten minute flight

30cc 26% yak 15 kg digitals = 150 to 200 mah per ten minute flight

All on genuine a123 2300mah homebuilt packs, pretty consistent power consumption, if after a days flying I found I had to put far more or less into one of these packs I would investigate as it is probably a warning that something is amiss.


</p>

RE: A123 Question
 

How about another A123 question..

I have a set of 2s A123 packs that have just 3 wires coming out, the power leads and a single lead..  How can I hook these up to my Hitec X2, as it requires (For charging LIPo, LiFe and Li-ion packs) power leads, as well as a Balance plug.. is where a way for me to make an adapter that would essentially give me what I need without having to take the shrink wrap off of the packs, and completely rewiring it?

Thanks, Craig.

RE: A123 Question
 

Your charger should have 'charge' and 'balance' settings. If you use the pack as a receiver pack just charge it, no balance lead required.