orangehat44

My Feedback: (1)

Ok Im pretty new to the electric stuff. Started flying glow last year and been pretty comfortable with the glow and bigger size planes. I got a GP Yak 55 flight flex for around the park and learning some 3d stuff.

I got the recommended ESC: electric fly one think its 25 amps. and a 1300mah 3s electric fly battery.

I know lipos dont like to be discharged past like 30-40 percent. So I have like a 5 min timer set on my tx to get a handle on the battery. Friday was only my 2nd flight with it and I forgot the timer till after I started. I probably flew a 7 ish min.

when I charged that battery it took 1200 something mah. which is most of the battery obviously. Why didnt it cut off from the esc? Is there away to set that up to ensure I dont do this again. I know its bad for the battery but am I okay for having made this mistake once? Thanks guys


lol this is why I like glow lol you know when you run dry and dont hurt anything (unless you crash dead stick) but I usually dont have the nerves to fly for the 15 straight min it takes to kill the tank. so im use to landing after 10-12 min filling up and taking off. hard habbit to break for the electrics.

-pkh-

My Feedback: (2)

If you can program your low voltage cutoff (LVC) value, then raising it will cause it to kick in sooner. However, most ESCs I've seen don't have much fine tuning for the LVC value, just 1S, 2S, 3S, etc. cell count settings.

If your LVC is set at 9V, they you should be able to pull most, if not all of the 1300mAh charge out of the 3S pack before it kicks in. Since the voltage under load is lower than with no load, it will kick in sooner with higher current draw.

I just use a timer to limit the charge I draw from my packs. If I forget to start the timer, then the the LVC should kick in before I damage the pack.

orangehat44

My Feedback: (1)

Yea this pack has a 2s 3s 4s selection. According to the package the lvc is 2.75 per cell. Like I said I dont understand much about the lipo/esc stuff. How do I want to run these. As its a 1300mah pack do i wanna use my timer to find flight times to run it down to around 400 or 500 mah or can I take it lower. I dont understand is it the voltage or the current level that deteremines that magic 40% number Ive heard for lipos.

if you dont mind. break it down for me the correct proceedure I should use as I make a branch into electric flight.

I will probably keep going glow for big stuff. But as i said i wanted some park flyer things for around home. So i figured I'd keep planes around the size of the yak 55 flight flex so I can stay in the 13-1500 mah batteries so I can have any plane I get for the park use the same batts so I dont have a huge about of batts lying around.

Like I said probably 7-8 min flight was 1200 some odd mah out of a 1300 pack. Do I wanna set my timer for 6or 7 min or less. I do forget to start the timer often As I said but i think i'll be able to get into the habbit. I just dont wanna mess up my packs and discourage myself from these electrics..

Thanks for the help!

-pkh-

My Feedback: (2)

I'm not sure what 40% number you've heard for LiPos.

In general, I buy inexpensive Zippy LiPos from HobbyCity.com, and I try to get at least 2X the C rating I really need, and I try to only pull out about 1/2 to 2/3 the total charge out of the packs.

For example, I've got several 3S 2200mAh LiPo packs with ratings between 20C-30C (44A - 66A max). The planes I fly them in draw only 17A - 22A, and I typically pull only 1200mAh to 1800mAh out of them before landing. Again, I limit this by using the timer on my radio.

The safe voltage range for LiPos is 3V to 4.2V per cell, and I believe it's pretty linear over the entire charge range. This means that at 4.2V/cell you should have all of your rated capacity available in the pack, and at 3V/cell you will no remaining battery capacity left. Running the pack down below 3V/cell, or charging it above 4.2V/cell can damage the pack. If your 3S pack is rated at 1300mAh, then you should have about 1300mAh of charge at 12.6V, and if you draw the entire 1300mAh out of the pack, the unloaded voltage of the pack should be 9V.

EDIT:
BTW, I use a timer (on my radios) for all my planes, nitro and electric, so I rarely forget to start the timer. If you are used to flying nitro planes, I'm surprised you are forgetting the timer for the electrics.

orangehat44

My Feedback: (1)

Thanks. On the timers I started flying the nitros on an old JR 632, no timer. At a friends property where theres only maybe 3 people there all day to fly. So we take turns flying rather than having multiple birds in the air at the same time. So I got use to go up for about 10-12 min on average then land to let another have the sky. And I usualy always had about quarter tank left. Now I got a DX6I recently with some helies on craigslist deal. so Im using the DX6i for my helis and electric park fliers as it doesnt have the wratched throttle so I wouldnt like to fly my bigger stuff on it, I dunno to me for some reason I feel I have less feel and control on the dx6I so I was going to designate it my smaller electric radio.

So your saying I should shoot to pull 8-900ma out of the 1300 packs (roughly 2/3). SO when I go to charge it on my Triton eq Im putting 800 ish back into the pack.
Did I potentially damage the pack by draining 1200 ish out of it last time?


Thanks for all the help.

-pkh-

My Feedback: (2)

You should be able to pull all 1300mAh out of the pack without damaging it, I just believe limiting it to 2/3 of the capacity will help extend the life of the pack, especially the cheaper packs I've been buying.

Personally, I prefer a smooth throttle stick over the ratchet version, but then I started out flying nitro helis before flying nitro and electric planes. My first radio was a heli radio (Futaba 9CH) with a smooth throttle stick, so I can't stand the ratchet version now. My DX7 is the heli version with a smooth throttle as well. Any radio I get with a ratchet throttle gets converted to a smooth throttle ASAP (just flip the metal tab inside). Even my Real Flight controller got the smooth throttle conversion!

Right now I fly my nitro helis and several nitro planes with my Futaba 9C, a couple nitro planes with my DX7, and all of my electrics with my DX6i. I also control an electric Coast Guard Life Boat with my DX6i, and a Nirvana Sailboat with a DX5e!

I power my DX6i with alkaline batts. One set of four costs me $1, and they last me for about half of the flying season. I never have to worry about charging it up, I can just throw it in the car with some LiPos and my electric planes and go fly. I just installed 3S LiPo packs in my Futaba 9CH and Spektrum DX7 radios this winter, so now I shouldn't have to worry about charging either of those radios very often.

orangehat44

My Feedback: (1)

Cool! Thanks for all the help. I guess I'm the opposite where I prefer the ratched kind lol, personal preference I guess. So from now on I'll play with the timer to get a targeted mah pull out of the pack around the 2/3 like you said. Im in college so money is tight, but I'm currently on a 6 month Co-op where I get paid a decent amount and can live at home so rent and food costs dropped to 0 which is nice . Obviously when I go back to school space will be tight so I cant go crazy, but I am definatly going to get a nice bigger radio. Been looking at the futaba 8c. And Im really trying to hold back on going nuts buying planes and stuff. would love to get a few more electrics to fly round the park thats by my house.

I have been staring at alot of things on Hobby king. I got most of my stuff from tower or horizon, cause Ive seen how alot of times you do get what you pay for and have heard some horror stories of the cheaper things. But I have seen alot of good reviews from hobby king. And seeing tons of bind and flys or arfs under the 100$ mark. and the batteries are pretty well priced. Thinking about getting some things from there.

Or ive been thinking about buying some depron and making some planes from plans from parkjets.

-pkh-

My Feedback: (2)

Yeah, HobbyCity/HobbyKing.com has some good buys and some cheap crap, so you have to be careful. Read the product reviews they have on their website, and look here in the RCUniverse forums for reviews on their stuff. In general, their LiPo packs and Accucell chargers get pretty good reviews. Their motors, servos, and ESCs get mixed reviews, so be sure to research the specific brand & model # for those.

So far I've found the ParkZone/Eflite BNF stuff flies pretty well and are worth the money. If you have a DX6i, then your all set for the BNF stuff.

orangehat44

My Feedback: (1)

Yea I got myself a PZ Su-26 micro, and was oogling some others. I like tower cause of the easy pay option and other deals. Horizon rarely marks stuff down so I never wanna buy from there but cant find many others that sell the pz/eflite bind and flys or pnps. I like the looks of that blade msr. As I said I got a blade cx2 and a blade 400 in a used deal off craigslist with the dx6i. Flew the cx fine of course and got bored with it quickly. Flew the blade twice before disaster struck. Ive replaced everything thats bad but am kinda lost in setting up and tuning it correctly. Friends have pointed out some things that may have been contributors to my crash in the tuning and set up departments. So i was thinking of the MSR to have a FP to step stone to the 400.

I also like the PZ warbird bnf and pnps for park stuff.

But I did like the looks of alot of the jets on HK. some of those 80-90 dollar warbirds and jets are pretty tempting. lol

Also they have a cessna with floats for 129. but all the reviews have people complaining about not recieving the floats. I dont have too many chances to fly off water. but every summer my friends take my GF and I to their cabin in the adirondak montains, we have to take a boat to get to the cabin. its right on a "flow" i guess not a river not a creek lol whatever a flow is. But its decently wide and usually quite calm when no boats are going up and down it (guess thats the flow namer) So a cheap water plane would be nice to try as Id have less of a loss if something were to go wrong. there is plenty of space there.

-pkh-

My Feedback: (2)

Usually [link=http://www.ultimatehobbies.com]Ultimate Hobbies[/link] and [link=http://myatomic.com]MyAtomic[/link] have discounted prices on Horizon stuff. Ultimate usually has free shipping on $150+ orders, and MyAtomic has free shipping on $25+ orders.

Let me know how the micro PZ SU-26 flies. Looks like they just announced an upgraded version of that, the [link=http://www.horizonhobby.com/Products/Default.aspx?ProdID=PKZU1080]PZ SU-26XP[/link]. I've been thinking about getting one of those. I've got the Vapor and the Ember. From what I've read, the [link=http://www.horizonhobby.com/Products/Default.aspx?ProdID=PKZ3680]micro Mustang[/link] in a pretty nice flyer too, and I love Mustangs.

When looking at prices on HobbyKing's site, be sure to look at shipping costs. Every item listing has the weight, and you can look up shipping costs on their chart. They ship from Hong Kong, and the larger/heavier stuff gets expensive to ship. It still may be a good deal, but just keep it in mind when comparing prices.

RC Trevor

I only read the original post now and if you new to electric and Lipo batteries I have an article on my website about Lipo Do's and Don'ts. If you interested in reading it you can find it here:

http://www.rc-universe.net/articles/#lipodo

Hope this helps...