Roxon

ok i been out of the rc game for like 7 or 8 years, just got back in, back then all my batterys were NICD, these LIPO batterys
are totaly new to me but they seem to be the best so i wanna learn em. i was doing some research on them but they seem awfully
complicated. so lets see if i got it right... plane im getting calls for 2, 7.4v 3000mah, 20c, with balance lipo batterys. the recommended
ones by tower are $80 each ouch. dug around on ebay i came up with this http://cgi.ebay.com/Turborix-7-4v-20...QQcmdZViewItem
the charger i came up with was http://cgi.ebay.com/ElectriFly-Trito...QQcmdZViewItem ok battery, charger, those im familar with, the balance thingy is new to me but i do need it right?? ok so i came up with this http://cgi.ebay.com/Astro-Flight-Bli...QQcmdZViewItem now im still not certain about the connectors and how the blinky hooks up and such but i can figure that out as i go along as long as these 3 things, batterys, charger, blinky are right to start me along the correct path. please any comments and advice, help, etc on LIPO setups and such is very welcome.

LDM

My Feedback: (15)

also new to e-flight but experienced in fule and warbirds . Your plan sounds good , I do know that you can hook up the blinky wrong so read the directions .
One of the most complex things for me was how to charge the batterys (at what amp) ect , then while reading a tower ad I noticed the batterys have the directions on them do example 2100 said Charge at 2.1 amps max 1500 said charge at 1.5 amps max , wow that was simple and it worked .
I have two charges , the astro flight for lipo because I was told it was simple and would not need another one for a long time and I also have the Triton , both very good .
Also I was told to get a separate battery for chargeing my lipos --possibly a marine battery but then I went to the guys at the field and they siad I was crazy that e-fly guys at the field have been flying off there cars for years .

Roxon

wow look at this monster!! http://www.maxamps.com/Lipo-12000-74-Pack.htm my plane can carry heavy 8.4v nihm 7cell packs
and lipo is lighter so i would think it could carry 2 of those bad boys! wow thats alot of current eh, bet i could get some nice
flight time with 2 of those monsters! now i have never crashed a trainer before, but GEEESUS that would suck to crash and destroy
them lmao.

LDM

My Feedback: (15)

I am thinking of getting the hanger 9 B25 , I know that baby takes some big batterys

Roxon

hey look at this http://cgi.ebay.com/Lithium-Li-Ion-1...QQcmdZViewItem it has 8 cells in it, but all the
chargers i can find say they charge 1-5 cells, so how can you charge that? does li-ion last as long as lipo? that battery seems
like a great deal 8800mah for only $57. but my plane says lipo 20c, so im still confused about the C thing, thats amps right,
the li-ion battery doesnt have a "C" rating so like um would it work?

Red Scholefield

My Feedback: (9)

This is what we could call a 2S4P 2200 pack. These cells do not have the current delivery capability of LiPo cells.
In the 2S confirguration your charger would probably charge them.

Roxon

well i have been doing alot of research the past few days, i think im figuring it out, the A123 cells seem to be pretty sweet for
around $10 each (buying the dewalt pack and taking them out) so now i want to try to make my own packs from them. my first post states what batterys my plane calls for, 2x 7.4v, 3000mah, 20c lipos or 2x 8.4v 3000mah nimh, ok so the A123s are 3.3v each, so
3 in series would be 9.9v right? and 2 in parallel would double the mah of a cell from 2300mah to 4600mah right? so a 3S2P battery
made from the A123 cells would be 9.9v-4600mah right? now im still a little unsure about the "C" rating it says 20C lipos, that
means discharge rate right? what it can handle load wise when being discharged right? from what i read the A123 is like 30C so
that would apply to the whole battery right? so the whole battery is like 30C right? if my numbers here are wrong please advise, ok so my
question is, can the ESC and motor in my plane handle the 9.9v batterys? and how is the esc looking at those batterys? like in series to 20v or in parallel? heres a link to the plane http://www2.towerhobbies.com/cgi-bin...=LXNVC0**&P=ML A123 cells drop to around 3v under load too so isnt that really like 9v, i tried to find exact specs
on the motor and esc but i couldnt find em. what do you guys think

Roxon

hey look a123 is selling packs and chargers now http://www.a123racing.com/html/racingPacks.html

Dr Kiwi

You are on the right track here, though I'm not sure why you need such a massive pack (at 30C the 4600mAh pack can theoretically deliver 138A - at roughly 9v that's 1250W!). I don't know what motor you are thinking of using, but it is unlikely to want a 6s 19.8v pack (and I'm not sure if the Electrifly 45A ESC could handle that voltage anyway - and it certainly won't cope with 138A) - I can't imagine the plane needing 1250W.

As you say they give you no information on the 42mm Electristar motor but I'd guess that it might be good for 40A @ 10v = 400W.

Roxon

hi dr kiwi, well it didnt even think for a second about watts! hehe i just started learning this like yesterday. my ESC on the plane is
a SS-45D rated at 45A i think. the motor is a hobbico 42 brushless, im having a discussion here http://www.rcgroups.com/forums/showt...61#post8313509 if you want to jump in you are most welcome, but i have been told that yes the 2 packs i was planning on building the 2, 9.9v 4600mah is to much for the ESC. i have been advised 1, 5S2P will work though, so thats what im planning on building now. what do you think about that? 1, 5S2P of the A123 cells?

LDM

My Feedback: (15)

whats the downside of these batterys are they heavier ??
I am asking because i remember when lipo first hit the scene , you did not hear about one downside not even the danger , and all you heard about is that they did not need to be balanced or cycled , trust me this was not urban legend , it was publised in many RC mags and on many RC post . Then reality hit with everything from fires to less run time from non cycles , to packs expoding on impact , so that is why I wonder what is the down side of these new cells

Roxon

Hi LDM, look at this page http://www.flyelectric.ukgateway.net/lithium-a123.htm as you can see the A123 has some nice advantages,
what i like about them is they dont catch fire or explode, (that really concerned me about lipo) and they have a higher discharge rate,
and can be fast charged faster than lipo, stronger cell than lipo (crashes, etc) and cheaper. the only real drawback is the 3.3 voltage
as compared to 3.6 on lipo, so making packs that have the right voltage may be somewhat of a challenge. my link above to my discussion about making a custom pack for my new plane we talk about that but we have decided it can be done no problem, ill be using a 5S2P pack which is 10 cells what comes on 1 tool battery. they are heavier than
lipo too and that may be an issue for some people, but not really for me. and you will need a new charger to charge them, unless you can program your charger to charge at 3.6v and not go over that. My chargers are NICD-NIMH so i was going to have to get a new charger anyway so im going to get the bantam bc6 which does all 3 lithium, ion, po, fe (a123) and it has built in balancer so i wont need to buy one of those. its ac-dc too i like that. to me the pros far outweighed the cons on the A123 cells.

Matt Kirsch

My Feedback: (21)

Roxon,

It should be mentioned that you purchased a Hobbico Electristar, a ".40-size" trainer converted to electric from the factory.

This plane calls for two 7.4V (2S) LiPoly packs, or two 7-cell NiMH packs, to be connected in SERIES to make a 14.4V (4S) LiPoly, or 14-cell NiMH.

1. My first advice here is, get your first packs from a well known vendor, not some fly-by-night Ebay operation. Since you're new to LiPolys, you need to eliminate as many unknowns as possible to make your first experience enjoyable.
2. Don't build your own packs, buy them premade. Soldering LiPolys is a very delicate operation, especially when you add the complexity of a balancing connector to the mix.
3. Buy your packs from a vendor that also has a balancing charger that works with the packs. That way, you don't have to fight with figuring out adapters right out of the gate.

Save the experimentation for later, when you are more experienced with the technology and know what to look for.

Do a real cost analysis of A123 vs. LiPoly. Sure the cells are cheap if you tear apart cordless drill packs, but you need to use twice as many. At $10 a cell, you're $40 into each pack, and you haven't added wires, connectors, etc.. Great Planes 3200mAh 2S packs are $80 each. Proven technolgy, pre-wired to fit the plane and interface with a balancer.

Roxon

Hi Matt, I am getting 2, brand new 3800mah 7cell NIMH packs for the plane. so i will be flying with those for a while.
only after i have had some good flight time in and back comfortable with flying will i be trying lithium batterys.
I have been looking at pre made packs of the A123 cells, by pro pack builders, I can get them for around $18 per cell.
but even though i have never built a battery pack i have done pinpoint soldering before and im pretty sure i can do it.
there are some very detailed guides on the net about building packs from the A123 cells which i would be refering to if
i do atempt to build my own. i am geting a new charger for them a bantam BC6 which chargers all kinds of batterys
including LI-FE. it has built in balancer too. i have done alot of researching over the past few days and i will be going
with A123 not lipo, thats for 110% certain. it would seem you dont think they are a great alternative to lipo, well
i would just politely disagree. its not only cost that i like about the a123. they are many advantages in A123
cells over lipo. mainly they wont explode or catch on fire and have higher discharge rate and reported to do many
more cycles over lipo. i just dont want to worry about my plane exploding in a ball of fire if a crash or my house burning
down when im charging my batterys both of which have happened to people with lipo but will never happen with A123.

sparky925

My Feedback: (1)

ok ok ok
I must admit this has been an interesting series of posts only to mean that Roxon is wanting to be serious about electric flight.
I commed him for this. but lets look at this for a minute.
I have flown the electristar with the NimH 14 cell setup. Good plane plenty of endurance, and great for training!!
now for the A123 statement. this is not a statement is 100% true therefore not something to live by. We need to always assume that any Lithum based battery is dangerous, because simply it is a high energy and potentially volitale cell that needs to be respected.
I dont have anything against A123 cells, but they are not as readily available, and i would rather not have to dissassemble a pack, resolder it, and then hoppe for the best.
Not one time have you mentioned you local hobby shop, only mail order. Do you have one in your town?
I know not everyone has a good local shop, but if you do, i recommend you partronize them, buecause you have a face to but with the items you have.
The local shop owners are there to help you! If you need 2 more control horns to get a plane flying on a thursday night, who is going to supply them for you to be able to fly this weekend? NOT mail order.
Ebay is a gerat sourse for lots of items, but remember that there is little to no control for accuracy for items like batteries. I can seell a pack as a 9000mAh even if it is only 4000mAh. Whos to know?
If you smoke a battery i can say that you abused it beyond its capicity and therefore voaided and required support. OK so you leave bad feedback, all i have to do is create a new account with new email address and i am ready to cheat someone else. NO that siad, NOT ALL EBAY SELLERS ARE CROOKS!!!!!!!!! but there are lots of them, so be carefull!!

Roxon

Hi Sparky925, good to hear you have and like the electricstar, i was very carefull in choosing it, i read the reviews about it first
and they said it was great. cant wait to get it still waiting on snail mail. man i WISH oh how i WISH i had a LHS store near me.
unfortunantly the nearest one is about 25 miles and it kinda sux the one i really like, its a big awesome shop, is about 40 miles
away. over the past few years i have become sort of a mail order expert. i like it alot, you have to be very patient, you cant get
instant gratification like if you buy something from a store, you have to be patient and wait for the mail. but when the stuff comes
its always top notch and worth the wait. i am VERY carefull about buying things from ebay and only buy things from people with
100 or more feedback and if you do that you -rarely- go wrong. i buy -alot- of stuff from ebay and the only problems i have had
are stuff getting lost in the mail. like i ordered a PC game and when the package came it was opened and empty someone had ganked
the game out! i was like [:@] but i emailed the seller and explained what happened and she gladly refunded my money, minus
the shipping, i lost like $3 on shipping, but owell, thats like the -only- problem i can recall for a LONG time. but also it should be noted
i have not bought ANY rc stuff yet from ebay, have tried on a few things but got outbid in the last minute []. so ill guess ill see how
that goes when i do buy rc stuff. i dont expect a problem though really as i said im very picky about buying only from high feedback people. ok as far as A123, the manufacturer is making and selling packs and chargers now. here is direct quote from their website "Inherently safe chemistry will not explode or catch fire
Twice the cycle life of competitive Li-poly batteries
50% more power (up to 60C burst) than competitive Li-poly batteries
Fast charge capable - reach 100% state-of-charge in 15 minutes using the Hypersonic SonicChargerâ„¢ balancing fast charge system.
see they claim wont explode or catch fire. i was reading about the cells, i did ALOT of research on them in the past few days. the lithium in them is encased in a carbon coat that makes them unable to catch fire. I mean im sure it would be possible to make them
burn or something but they wont explode in your house or your plane thats the point i was trying to make. but i have never bought
any lithium batterys yet and they are expensive, so my theory is, when i DO buy some i want the best, most safest, longest lasting cell
i can get and A123 seems it so thats what Ill get. I am going to run the plane on NIHM for a while it will be some time before i actually
do the whole A123 thing. but when i do it im gonna come here and post how it goes.