gencollon

How many cycles (charge and discharge) can a single lipoly pack go through before it doesn't work anymore?

I hear it is far less than a nicad or nimh pack, but have ever gottne an actual number.

Thanks.

Chocks_Away

I read somewhere that a lipo will only last upto around 300 cycles against the well known alleged 1000 for nicads, but having said that, I have yet to own any nicad that has been cycled anywhere near as many times as that, as they usually have given up after 2 or 3 years, regardless of how many cycles they have had.

I reckon you would have to use a lipo a hell of a lot to get all those cycles out of one even if you could get that amount of cycles.

Also, Lipos are supposed to lose a noticeable amount of their capacity after a few dozen charges.

I have converted to lipos with 2 of my planes a few months ago, but my lipos have only had about 6 cycles each on them, so it's early days with mine, so can't say for sure what will actually happen to their capacity.

But even if you could only get 300 cycles on a lipo before it's no good anymore, then you would have to use it 3 times a week, every week for 2 years to accumulate that amount of charges, so they still represent good value for money I think

gencollon

Yeah, I would agree that they are a great value for smaller electric models, as they will lighten your plane a ton while still giving longer runtimes.

However, I am looking to buy a century swift (.30 size) electric helicopter for aerial photography, and there are a ton of motor setups out there, but some people run two 22 volt packs in parallel, with 3000 + mah. With all this, they only get 10-12 minutes. I would probably get two batteries, and so I may be spending $300-$500 on two battery packs!

I was wondering if they're even going to last long enough to justify the price,

And I haven't done the math, but I would suspect that in smaller models, where you would get a $50 or $60 lipo pack, it would be much more cost effective than using glow fuel.

Oh, and if anyone who sees this thread flies a century swift, what batteries do you use? and how much do they cost?

P.S. I think I will go with the neu 1907 motor because I need the power to carry a camera, and I hear the neu motors are highly efficient.

Chocks_Away

10-12 minutes sounds a bit poor for 3000 mah packs, but as it's a heli, I'm not sure what the current draw will be on one of those.
But as you said it's a .30 size, then it's gonna take a big motor to run it anyway, so the 10-12 mins runtime doesn't seem so bad then.

I know what you mean being wary of spending that kind of money, but to start with you have got to double up a battery to get one flight anyway so you can get the 22volts with two 3 cell lipos, & then buy another one so you can get a second flight, making it a total of buying 4 3000mah 3cell packs, so it's going to be expensive anyway.

If you want to be sure of them justifying the price with good reliability, then don't settle for second best, only consider buying lipos of the well known branded type to be sure.

That's the only problem with the larger size of electric conversions to their IC equivilents, - big motors cost bigger money to run !

Tall Paul

I've seen some Li-po packs with over 100 charges marked on them. These are large packs, handled properly. What the limit might be, I'll watch..

gencollon

Yeah, I guess I'm just gonna have to go for it, and get a pack or two of evo batteries. I am looking at these http://www.heli-world.com/detail.aspx?ID=4218

Any battery that costs $240 or so has to be at least decent quality

Then I need to solve the problem of charging them............the money flow continues.

Oh well, I am looking to do AP, in tight spaces, so a 30 size heli is what i need, and electric is better so as not to disturb people when flying around residential areas, so it is either the swift 16, or one of the logo series, which I believe is even MORE expensive.

Chocks_Away

I see..
I thought you were going to buy 2 3cell packs to series up to give you the 6 cell pack that you needed, but not the case, you are on about buying a ready made 6 cell pack.

The same pack in the UK works out at the equivilent of $273 US dollars, so you can get it at a bargain price compared to me [sm=lol.gif]


In the UK (which is probably no different to you in the US) you can also get two of the flightpower packs in the 3 cell packs of 3700mah for the same price as the single 6 cell pack, right ?.................

What I am thinking is, if you say you have got to get a charger as well now to be able to charge it up, then it would be a lot cheaper to buy a charger that can charge 3 cells than a charger that can charge 6 cells, as the chargers that do upto 3 cells are a lot more common, and will thus be cheaper, so you may be better off getting 2 3cell packs, & just series them up to give you a 6 cell voltage to make it a bit cheaper for you.

Also, if something happened to the 6 cell pack, and it went faulty, or you damaged it by misuse or wrongly charging it, then you will have knackered one big expensive pack, but if it happened with only one of the 3 cell packs, then it won't hurt your pocket as much.
Just a thought thats all.

Personally if it was me, then I would opt for 2 seperate packs of 3 cells for definate, but at the end of the day, it's your choice.

The flightpower batteries seem to have built up a good reputation, and are widely thought of as one of the best you can buy.

gencollon

You know what??

That is a really good idea.... And a 3 cell pack at 3-4000 mah should only be what? $70-$120? I may save a little money doing it that way, AND I could use each 3 cell pack in a smaller heli, or plane as well

Chocks_Away

yep, you sure can can't you.

Your not tied to keeping that one battery pack so that it's only any good for just one model then

Flypaper 2

Li-ion packs are coming along pretty good too. Bought a couple from Home Depot that fit the Makita drills. 18.5 volts 3000 MA. A little heavier than Lipos a a heck of a lot cheaper and tougher as far as abuse goes . and with the proper charger, charge in 20 mins. Paid 119 bucks a piece up here in Canuck land. Still waiting for a special cable for the FMA Balance Pro. On a conventional lipo charger takes 45 mins. The guys flying helis think they're great. Talking a 1000 cycles to, but that remains to be seen.

Chocks_Away

We don't seem to hear of Li-ion's here in the UK now, its been taken over with Li-po's
And the newer Li-Saphion types.

Hatty

There is very little difference between the "classic" lipo and li-ion packs. In fact, Li-ion came out first and then lipo which ended up being slightly better (if I can remember correctly, so someone correct me on this if im wrong). The reason why the Makita batteries can take so much abuse, from what I have read, is becasue of the way they engineered them. Something about the atoms and...ah, I'm not a chemist. You get the idea. It's VERY new technology. And, electric aircraft do not need a battery that can take all of that punishment. I am guessing that they will be branching out with that technology and putting it in more and more electronics, but until then, we have to wait for it to trickle down to us.

gencollon

we already ARE using them, In fact, it is what I have decided to use in my future swift. They are cheaper than equivalent li-pos, charge faster, and are virtually indestructible...

Flypaper 2

My kind of flying, I need indestructible. Read on one of the other sites where a guy piled in a 1/4 scale 3D type plane straight in from about a 100 ft. Batt survived but not much else.

Hatty

In that case, where can I get one! I must have one, NOW! If I can treat my Lipo like my NiMH, then I will be extremely excited. Thanks for pointing that out by the way.