yepe

Guys, what is a cheap F3A 5S 5000MAH battery. Any suggestions about Rhino, Zippy or Turnigy Nano tech batts? Thanks

RC_Pattern_Flyer

My Feedback: (1)

skylipo from hobbypartz

chuck

Jetdesign

My Feedback: (8)

My Rhinos have been very solid for 2-3 years - I've used Blue Lipo, Zippy, and Rhino, and would buy a whole fleet of Rhinos if I could find the size I wanted.

The Blue lipos are very light and work well so far, but only about 30 flights on them I think.

F3AUnlimited has good packs at a good price - more than the cheap Chinese packs, but light and strong and with some support.

cmoulder

I also like the Rhinos, but I agree the 5S 4400 40C Sky Lipos are my recent favorite, at $39 apiece from Hobbypartz.

But the OP is from the Philippines, so the Hobby King shipping would cost a lot less, I would imagine.

jayjayneri

Hi Bob. Can you elaborate on how the Sky 4400 40c lipos differ from the Rhino 4900mah lipos in performance? I am curious as to the differences between both in flight time, punch and throttle curve. I am using and love the Rhinos but wondering if a 35c or higher rated batt would be better or would it just make the throttle more difficult to manage. Thanks

cmoulder

jayjayneri, there is no doubt that the 40C has more discernible punch, and with the Plettenberg xtra 30-09 it can provide more power than is needed - a little over 4000 watts. You are absolutely correct that the throttle curve must be tweaked and that the upper end point might need to be lowered somewhat, depending of course on what motor and prop you are using.

I am still working on the throttle curve for my set-up and am 'almost there' after about 25-30 flights in varying wind conditions. The throttle curves for the Sky 40C batteries and the Rhino 20Cs will not be the same, so it is a good idea to copy the original model settings on your Transmitter if you fly the higher C batteries.

The sequence I fly is AMA Advanced and there is plenty of flight time for that. I think they would be fine for Masters as well, but beyond that I don't know about FAI P or F.

The data graph is from an AMA Advanced flight with the Sky 4400s, Pletty 30-09 and Falcon 20x13 prop. The initial spike is a brief (3-4 sec) full power run-up to more than 4000 watts. However, you can see that during the flight it needed about 3000 watts maximum. The amperage draw is somewhat high, but the temperature graph reveals that the ESC did not get hot and upon landing neither motor nor battery were hot, just warm, in fact.

degray

My Feedback: (15)

I'm just converting over to electric from glow and need to get a number of battery packs. Initiallly I was told that the Gens Ace were good, however thaey are a little pricy and Hobby Partz is out of the 5300 5S 25C. They do have the 4000 5S 25C in stock. My question is, would 4000 mAh packs be ok to use for c values of 25 or more? I'm flying Sportsman Class and the nomoral flight time is under 5 min. With glow, I could do most of the maneuvers with around 1/3 throttle. Perhaps the torque curve for electric is differnt requiring higher throttle levels. Without including any losses, a quick and dirty calculation of the mAh used in a 5 min. flight with average power of 50% is around 2900.

RC_Pattern_Flyer

My Feedback: (1)

Go with the sky lipo 4400 20c packs, you will not regret.

Chuck

cmoulder

Chuck,

How many cycles do you have on your Sky batteries?

Obviously I am very happy with the batteries but the most cycles I have on one set thus far is 16, with 11 and 12 each on two other pairs.

Just wondering if the fantastic performance will continue thru 80 or 100 cycles. I am taking care not to overdischarge them because I want them to last a long time.

cmoulder

For Sportsman, it will likely be a lot less than that, depending of course on wind, throttle management, maneuver size, etc. Flying Advanced big in moderate wind I am using about 3000mAh avg. Precious little calm weather of late so I can't say much yet about power consumption in light air.

RC_Pattern_Flyer

My Feedback: (1)

I am close to 50 cycles. No drop in performance and I charge at 2c.

Chuck

degray

My Feedback: (15)

Thanks for the info. Looks like I will try some Sky 4400 40C. Do you recommend charging then at 1C for the first several cycles?
Don

nonstoprc

My Feedback: (90)

I normally fly at 50% throttle for the 1st two flights with a brand-new pack. Just fly it around gently.

The latest information I received from a technologist at a big information technology company (name start with H) on charging LIPOs is to charge at 1C. This will extend the life of the battery.

degray

My Feedback: (15)

Thanks for the recommendation NonstopRC.

Jetdesign

My Feedback: (8)

I think Zippy batteries are crap. I can't believe so many people say they're not bad; they're cheap, that's it. My 30C packs lost their muscle after a couple dozen flights. My 20C packs have maybe 50 flights on them at most and are now dropping down to 3.2-3.3V under load. They are clearly the weak link in my system.

jayjayneri

I totally agree. I lost a plane recently because of a Zippy rx pack that read ok on the Futaba BR3000 battery checker but failed under a 1 amp load using the older Futaba BR2000 battery checker. The Turnigy and Rhino packs seem to be holding up well though. Never again will I use Zippy batts and I now use both Futaba battery checkers for checking my rx batts. A very expensive lesson learned. Just my 2 cents worth.

cmoulder

Joe, I have 3 sets of the Zippy 20Cs and 2 of them are still doing 'okay' after more than 100 cycles, and one set remains uncannily strong. Any of them are capable of flying the Advanced sequence, with the one really good set equal in performance to the Rhinos.

Not one of the 20C packs, however, is in the same league with the new 40C Sky batteries.

My only complaint is that the balance tap wires on the Zippys are a very stiff and with a low strand count. Two of the wires on one balance tap recently gave way and I will have to re-solder them.

jayjayneri

cmoulder

You MUST use a battery checker that tests voltage under load! I have the one from NoBS batteries that has an option for .5-amp or 1-amp load. It has saved 2 or 3 planes that I can recall. [link=http://www.hangtimes.com/chargers.html]NoBS battery page[/link] here and scroll down to LoadMaster battery checker.

When recharging your main batteries, always check the IR numbers at then end of the charge cycle to detect a Lipo that is going bad. The CellPro chargers have this capability which is IMHO indispensable. If you see IRs of 1.7, 1.9, 1.5, 1.6 and 23.2, you know you've got a cell that has gone bad!

Jetdesign

My Feedback: (8)

My packs are flying the intermediate sequence pretty well, but I pulled the data from the data logger and found I was running under 1800 watts (110 size plane) and pulling about 65A. I was interested in trying more prop, but the voltage is dropping down to 3.2V/cell under load, so they're pretty close to maxed out imo. These were new last year and not many flights on them. My first set of packs (30C) lost a ton of punch in not much time at all. I have (had) 3 sets of 20C packs from last year, one performing like crap and the two used here. I'd like to think they're not bad, but 4 sets of packs and I have not been happy with any, in contrast to the Rhinos, and even the Blue lipos which have looked good so far, but not too many flights.

shannah

My Feedback: (5)

I wish they still had the 20C's in stock. I really like those. I have the 40C and it has more punch but the 20C is smoother. Since the 20C's seem to be gone forever I will adapt a throttle curve for the 40C's.

cmoulder

This has been a bit tricky. I find the transition from low throttle to middle "cruise" speed is pretty touchy, and even with a 9-point curve it is taking some work.

nonstoprc

My Feedback: (90)

Looks there are still plenty choices for packs with discharging rate at 20c and 25c (e.g., TP G6 Pro series, or f3a unlimited 25c, etc). All have enough discharge capacity for pattern, and lighter than 40C version.

cmoulder

But the Sky 4400 40Cs are $39.

cmoulder

Looks as if they're [link=http://www.hobbypartz.com/77p-sl4000-5s1p-20c-5555.html]back in stock[/link]!!