Li Poly batteries, fantastic

Hi,
In only a few months since I've been introduced to Li Poly batteries, the developments in Lithium Polymer batteries grew in leaps and
bounds. Please witness the following specs and prices;
2 series, 8.5amp (nominal) li-poly 850mah 7.4 volt pack $29.28
3 series, 11amp (nominal) li-poly 1100mah 11.1 volt pack $53.52
2S3P, 33amp (nominal) li-poly 3300mah 7.4 volt pack $116.64
2600-4S4P, 104amp (nominal) li-poly 10400mah 14.8 volt pack $465.92
10S3P, 78amp (nominal) li-poly 7800mah 37 volt pack $873.60
These people make packs on order and have a huge list. I have only a partial list here. Perhaps some of you already knew about this, but I could paste their web site from which this info was derived if it's not unethical to advertise, but not for me?
Wan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Wan wrote:

try www.cheapbatterypacks.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I checked into your web site and I believe the batteries there are basically of the smaller types, right? See if this is not more comprehensive?
http://www.tanicpacks.com/BatteryListing.htm
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I should have said the website you presented. Thanks. Perhaps you may have done some testing on these batteries?
It's just that I am awed by the rapid progress made in the field of batteries. Who knows what else technology may bring forth?
Wan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Wan wrote:

The cells are good enough: More work needs to be done to make them less l=iable to explode under abuse, and to make theme cheaper.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
| 10S3P, 78amp (nominal) li-poly 7800mah 37 volt pack $873.60
And in case somebody wasn't paying attention, this is exactly why we don't see many large electrics yet.
This battery pack puts out up to 2900 watts, or 3.8 HP.
This would be comparable to an OS FX 1.6 engine, which puts out up to 3.7 HP. And costs $270.
This battery pack will put out that much power for 6 minutes *at best* (since it's a 10C discharge rate.)
And this is just the battery pack -- there's no ESC, no motor (with this much money going inot just one battery pack, it's silly not to get the best brushless motor you can find. And of course, it won't be 100% efficient, reducing the actual power you get.) You're looking at many hundreds of dollars more for that.
And of course, you usually want at least two battery packs ... the costs add up very fast. Some say that it all evens out in the end, that you're essentially buying all your fuel up front. There's some truth to that, but it still seems that large electrics still cost a lot more, both up front and over all.
The `sweet spot' for electrics is still the Speed 400 and smaller sizes. Once you get larger, the price goes WAY up. If you double the power, you basically double the price. (Compare this to glow, where if you double the power, you add maybe 20% to the cost.)
That said, I bought some Li-poly packs for my smaller electrics, a XE2 with an Astroflight 020, and an Electrifly with a geared Speed 400. Both got two cell packs, the first was a Tanic 2200 pack, and the second a 1700 mAh pack of some sort. They're quite nice, though I wish I had a three cell pack in the XE2 -- it has less power now, but a lot more duration.
Someday (hopefully soon!) these batteries will come way down in price. That will be a very good thing!
--
Doug McLaren, snipped-for-privacy@frenzy.com
Don't spend two dollars to dry clean a shirt. Donate it to the
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I am also waiting for the cost to come down. The fuel arguement is only valid when thinking long term. I don't know anyone who paid for all the gas their car would use at the time they bought the car.
Another thing to consider is the charger for such battery beasts!

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Paul McIntosh wrote:

Heck, not many people pay for the car upfront!
Lease those lithiums. Theres a new business oopportinity for you Paul!

Not particularly hard to engineer. 8A at 40V or so.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The point is, you still have to pay for all the power up front with electrics. That is what's keeping them in the minority so far. How many people would even start glow if they had to pay for 100 gallons of fuel every time they thought about a new plane?

gas
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Wan,
I completely believe that electrics will continue to grow in popularity, but not become dominant until something is done about the entry fee. You can get a VERY nice .50 size glow powered model, ready to fly, for under $250. That includes plane, radio, engine and fuel, etc. To get equivalent performance with electrics still costs much more. Some of the examples here talk about near $1000 just for one battery which has the potential for performance in the 1.5 glow power range. Add in the cost of motor, speed controller and charger! And yo have ONE flight. Want two? Wait while your battery charges or spend another $1000 for a second battery.
Electrics are getting there, but are still hampered by cost in anything over the speed 400 range.

only
the
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Paul McIntosh wrote:

You cam get a ready to go firebird for under $100. Its perfectly possible to get an sub 250 dollar leccy plane, it just isn't '40' sized.
THAT is what 'entry level' leccy flyers start with.
They can always get greased up later on...:-)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Again, I couldnt be happier with my electric Slowstick. Mind you, we are talking about ENTRY level here, although two or more expert pilots with slowsticks and a few 6 foot combat streamers could have hours of fun (i sure do) - im getting away from the point. Screw the firebirds, they really do look like wal-mart toys. Not that the SS looks beautiful, but at least it is Hobby Grade stuff.
Logically, one would 'enter' the hobby with an inexpensive electric foamie (such as i did) Move on to a bigger/faster/sportier electric OR a .40 trainer plane, depending on outside factors like your proximity to a club, LHS stock, luck with the electrics, etc. From there, you can either go with an even bigger electric, or a sportier glow plane - this is where the cost of electric really starts getting silly.
Ive learned so much about handling a plane in a few short months with the SS - i couldnt imagine trying to learn the 'old-fashioned' way with a balsa/glow trainer from the start. I did, however, just apply to the AMA, and im looking for a local club. Hopefully, i can hook up with somebody there who can help me learn to fly this old Eaglet that was donated to me. It should be easy to get used to, but i dont wanna take a chance with crashing a balsa/glow plane first time out. Mike

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
You are comparing apples to oranges AGAIN.

but
can
$250.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Paul McIntosh wrote:

No, I was pointing out that you were, AGAIN.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Maybe you can't handle anything above a Firebird so you think it is the same as a .50 powered plane.
That is the only reason I can see for calling them the same thing. You only want to compare price because that is the issue. You can't get equivalent performance in anyting over speed 400 without the price going way over that of glow. And, you have to consider ALL of the costs, not just the plane and batteries,

popularity,
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Paul,

Not very accurate. Most entry level EP's are as you say, except some like the Aerobird Challenger.
You can get a HobbyZone Aerobird Challenger for around $150.00 which includes EVERYTHING needed to get started & is far more durable & forgiving than most glow trainers. I fly mine when some glow's think it's too windy & fail to show up at the field. The ABC even comes with 2 flight modes, so beginners & advanced pilots can have fun with them. Put in the optional 7 cell/900 mAh battery pack ($30.00 avg) & it screams! --
Jim L. https://sourceforge.net/projects/virtual-access / Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Like TNP, you are comparing apples to oranges. The entry fee I was talking about is not entry LEVEL.

$250.
forgiving
&
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Paul,

That's the whole point here, entry level costs of glow vs electric.
This time you're off base, as my comparison *IS* entry level. No two ways about it. My example comes complete & includes everything needed to get airborne. A simple head to head comparison of what it takes to start in EP. --
Jim L. https://sourceforge.net/projects/virtual-access / Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I was NOT TALKING ENTRY LEVEL AND NEITHER WAS ANYONE BUT YOU TWO.
When I say entry fee, I mean the cost to get a specific level of airplane to the flying field, in flight ready condition. You guys read something into it that I did not type.

talking
EP.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.