1300 lipo

[skeeve666]

hi all, new to this forum and i need answers ;]

I have a dragonfly 4, after way too many expensive crash with my old hirobo shuttle ts, and i got kicked out of my heli club for not flying and missing meetings, hell i could not afford to rebuild after a nasty nosie in crash then ended up working lates and nights for 5 months.

anyhew

i got fedup with nicad and nimh bats and bought myself a lipo
2 cell 7.4v 1300mah 14c, but i get way less flight time and power from this, although i think its the charging rates, as i have no idea what the correct setting on my pro-peak prodigy 2 charger, the pack came with little info, as i bought it from ebay. i have never let it get below 7.6v and run about 6 cycles so far.

i currantly charge is via a jst at 0.5amp but after reading the sticky would a charge rate of 1.2amp be better?

as after the charger says its charged i can only get about 2-3 foot off the floor

i charge the battery in a ceramic crucible and never leave it alone..

would it just be better to pick up a balance charger?

[G-MRM]

Hi, You are corect, charge at 1C wil be 1.3 amps so 1.2 would be on the safe side. Your rate at .5 will take you twice as long but it should have still charged it Ok.

You have it set the charger to Li-Po, (just making sure !!) after a charge it tells you the power it has put back into the battery, what is this value ?? You should never take out more than 80% so your looking to put back about 1000ma (1amp) after use. Your old pack was a think a 7 cell pack, 8.4 volts so your down a volt to start with BUT you shoud get about the same time out of the battery, maybe less as you can't discharge it too low.

A balancer is good for the battery but something don't sound right to me. It only gets 3-4 feet high but can you fly like this for say 8 to 10 mins ? If you put the std battery in, is it then Ok?

Let us know and also the power your getting back into the Li-Po after a full charge and then a flight !!

[swatson144]

G-mrm is right on.

The 2s pack should do well on the #4. It's 1 volt lower but more than compensated by the lower weight and more importantly the ability to hold the voltage up under load so you see about the same voltage and better performance all around.

We need to see the info on the charge, as requested.

You didn't mention how many flights you've had on the main motor. Getting fed up with NiMh would indicate more than a few. The stock walkera motors are not noted for longevity. It may be time for a carbon brushed motor. The motors from the esky FP, GWS mdf, century humming bird fp, etc will all work well and give a good life span. At less than 10$ is a handy test component.

While you are sorting it all out it may be a good time to put a 6A automotive blade fuse on the main motor and a 3A on the tail, to protect the 4n1 from shorted/stalled motors etc. The 4n1 is the heart of the heli.

Steve

[skeeve666]

thanks for the replies ;]

i am on my forth motor, i have only just replaced it withing the last few days both the main and tail, there both carbon brushed Would love to get a burshless but i think i will have to upgrade for that), thanks for the idea of the fuses, i have lost one 4 in 1 to a main motor. i have also just replaced the main pinion and shaft along with a superskid upgrade. thanks to a cat, i have had to replace most of the head. thankfully all the parts are so cheap.

my himh`s i can get to about 20+ feet outdoors, with a 7min flight time.

the flight time is about the same on the lipo, but as i cannot get it anywere near out of ground effect it tends to get unstable thanks to good old mr turbulance.

ya i have set the charger to lipo 7.4v it charges to about 8.3v ( i know its 4.2v per cell max)from around 7.5-6v start voltage and takes about 1 hour to charge, never realy checked its finishing voltage, as i just want to unplug it and let it settle for about 15mins once the cahrger beeps. i would get killed if there was a fire ;[. she was not happy when i told her how potecntially dangerous they are.


i have just been test flying with the lipo in a min i will be putting it on charge @1.1amp. still dont want to push it too hard until i get mor confident with them. also flown with one of my nimh`s so there is no problems with the heli

stay tuned

EDIT __________________________--

just finished charging @1.1amp it started at 7.675v the charger took it to 8.399-400v and held it there then after awhile started reducing the ampage down a finishing 0.13amps the final output from teh battery was 8.437v stable is this okay? unfortuntaly its too windy to try outside atm and some friends have come round for a p1ssup so no chance of testing till tommorow.

thanks for the advice ;]

[swatson144]

The charging parms sound fine.

The superskids are pretty heavy. I tried a set and then gave them to a friend for his CP2. I use the stock stickmans. I just repair them with 2mm cf rod in batches.

I'm pretty stumped on why your #4 performs better on NiMh than 2s lipo. I would suspect the LiPo is not up to the task like made from low C cell phone batteries or something. Do they get more than just warm?

Steve

[skeeve666]

nope never get above warmish

they are rated at c14 so i thought they would have a high output, i bought it from superskids, but i have since seen 2000mah units at the same price but with c8 or 10

i have dug out some fuses, will solder them inline in the moring.. if i can hold a iron ;]


thought sod it and tried the helo in my living room, trouble is its realy too small to fly in as turbulance kills u after about 30 seconds. performed alot better stayed nice but still not up to the same flight times as my nihm... think i will go back to the standard skids and try them.

[G-MRM]

Well, sounds like a bad battery !! ??

I thnk it will be hard to help unless you have a amp / volt tester or you can try another Li-Po ! I stick to well know brand Li-Po's and have been almost happy with batt life, we always want more cycles out of them !!! Can you borrow one or let someone try your battery ??

Martin