New HYPERION LiFe RX packs. Enough amperage?

[Propbuster 1]

Am looking at possibly using the new Hyperion LiFe RX packs and was hoping someone would know this info

On a 25-30% Gas airframe using 5-8 high torque digital servo's + one analog for throttle, what would be the typical amp draw?
I know this all depends on style of flying and specific conditions but would that setup be capable
of drawing more than 8 amps?

I see Hyperions new LiFe packs in the 1600 mah has a rating of 8.0 Continuous available amps with 20 sec burst of 12.8

1700ma pack shows 8.5 with 20 sec burst of 13.6

[Wojcigitty]

I think you would be OK. Make sure you have no binding in your linkage or fighting (no reason to use more than one servo per surface on a plane that size anyway).

The Fromeco 5200's that people have been using on 40% airplanes for ever are only capable of 8 amps. Granted, we usually use 2 of them, but you will have half as many servos.

The only thing I would be concerned about is flight time. I'd bet you would only get about 4-5 flights per charge.

[Propbuster 1]

4-5 flights would be more than enough.
These are the new LiFe chemistry that allows charging at high amps which end up getting a full charge in under 20 minutes or so.

Thanks.

[Wojcigitty]

Care to post a link where I could find these batteries?

[Spdstr280Z]

Not exactly all over the place, all my friend Google could find, quickly anyway.... If you don't mind ordering from Europe...

http://www.rcmarket.org/rx-life-66v-...-pr-41057.html

[Propbuster 1]

I bought the last pair of 1700mah packs Randy of RC Dude had today.He's out of stock on the 1450's thru the 1700's till Friday when he's expecting another shipment.
He has the 3000mah and 3800mah in stock though

Here's a link to his page on them
http://www.rcdude.com/servlet/the-Ba...iFo/Categories

here's Hyperions page listing the whole line along with specs in a single page listing
http://media.hyperion.hk/dn/fg3radio/

Same chemistry as A123 but in LiPo type cell structure. A bit lighter.
The 2 1700's weigh 6.6 oz versus 2 1100mah A123's at 6oz OR one A123 2300mah pack at 5.5oz
Guaranteed for a year.
Check out the footprint of these packs too! The 1700's are roughly 2" x 1.25"x1.25" !!!
They only came out something like 2 or 3 weeks ago.

Maybe this thread can start a discussion on them.
In one fell swoop they went leaps and bounds beyond A123 for Giant Gasser applications

Paid $50 for the pair of packs versus $50 for ONE 2300mah A123

[hornet dave]

www.allerc.com

[Propbuster 1]

HUH! I didn't see them on there. I could only find one size pack on their site.
gotta go back and check

[hornet dave]

http://www.allerc.com/product_info.p...oducts_id=4721
http://www.allerc.com/product_info.p...oducts_id=4720
http://www.allerc.com/product_info.p...oducts_id=4719
http://www.allerc.com/product_info.p...oducts_id=4717
http://www.allerc.com/product_info.p...oducts_id=4716
http://www.allerc.com/product_info.p...oducts_id=4722

[Propbuster 1]

thanks Dave

[hornet dave]

de nada senior

i hope these batts work out OK. I want to switch my helis over to them this winter.

[dick hanson]

	Quote: Originally Posted by Propbuster 1
	I bought the last pair of 1700mah packs Randy of RC Dude had today.He's out of stock on the 1450's thru the 1700's till Friday when he's expecting another shipment. He has the 3000mah and 3800mah in stock though Here's a link to his page on them http://www.rcdude.com/servlet/the-Ba...iFo/Categories here's Hyperions page listing the whole line along with specs in a single page listing http://media.hyperion.hk/dn/fg3radio/ Same chemistry as A123 but in LiPo type cell structure. A bit lighter. The 2 1700's weigh 6.6 oz versus 2 1100mah A123's at 6oz OR one A123 2300mah pack at 5.5oz Guaranteed for a year. Check out the footprint of these packs too! The 1700's are roughly 2" x 1.25"x1.25" !!! They only came out something like 2 or 3 weeks ago. Maybe this thread can start a discussion on them. In one fell swoop they went leaps and bounds beyond A123 for Giant Gasser applications Paid $50 for the pair of packs versus $50 for ONE 2300mah A123

These new packs sound very good - anything which eliminates using a regulator in the model is an improvement
The packs are NOT identical with A123
The ratings show that
They are much the same tho.
Example
A123 are rated at 3.6 v per cell (fully charged ). and nominal is 3.3 volts
Hyperion has a 9.9 volt pack which is a 3 cell which is 3.3x3=9.9volts
for A123 this would be 3.6x3=10.8 volts fresh fully charged.
When I mention A123 -I mean genuine A123- not a knockoff FeO4
Prices for all my own packs never exceeded 12 bucks per cell -using VPXand DeWalt sources
For pre-made packs these new Hyperions really look great for use as radio /ignition power supplies.
Just not exactly same as A123

[Propbuster 1]

Take it easy Dick.
read the whole listing of their offerings.
Yes they have 9.9 packs FOR TRANSMITTERS
AND they have 6.6V packs for RECEIVERS

Nobodys impuning anything about anybodys quality either.

[wildhare]

To expand on what Dick said, the LiFeP04 is similar but not identical to A123/LNP
(Lithium-Nano-Phosphate). Bot have a nominal voltage of 3.3 v per cell which is ideal for receiver use, and they share other features; safe to charge, rugged packaging, fast charging, no self discharge.

The difference is in the internal resistance. The A123/LNP cells are more able to put out massive amounts of current for the entire discharge cycle, whereas LiFePo4 has a more modest output. On the positive side the LiFePo4 cells have a higher energy density per weight. This means that you can get more power from the same weight cell but it takes longer to get it all out.

In your application I would say that, based on your specs you will be right on the edge. You said a 25-30% and 5 to 8 servos, that's a big range. A typical 5 servo 50cc type plane will have a peak draw around 10 amps in a hard snap, the rest of the time it will be drawing 2-4 amps. These numbers are well within your stated battery's range, but I'd want to do some testing to verify that the batteries perform as stated, because you don't have a great deal of margin.

FYI I made up a pack from 2 K2 Battery LiFePo4 cells. These are rated at 3200mah, and had an actual output in my testing of almost 3500mah. These are the same size and weight as a 2300mah A123 pack which has an actual output of just about 2000mah. So the LifePo4 has about 50% more capacity than the same size A123. But at what cost?

I used my tester setup to run down a fully charged pack, as I do regularly with A123s to do spot testing. My test consists of an electric motor with ESC, an old receiver and a whatt meter. I can plug in whatever battery I want and set it it run at whatever power setting I choose.

What I do is set the tester to draw it down to no less than 5 volts, then measure how much power can be drawn from the pack on a continuous basis.

Normally in this setup with an A123 2300mah pack I can pull 20 amps for the life of the pack, +/- .1 volts, until the pack is pretty much depleted.

With the K2 LiFePo4 I was able to draw 15 amps without dropping below 5 volts, trying to draw more than that pulled the voltage down below my arbitrary limit. But in doing so the pack ran at that level to almost 3500mah discharge.

I was quite pleased with these cells, for a receiver application they are excellent. Not as impressive as A123s for electric cars or other very high demand applications, but when properly sized to a receiver/servo application they are really excellent. One pack like this flies a 50cc plane with lots of margin and does it half-again as long as an A123 pack.

TF

[ljaganna]

How about the Li-Mn....that chemistry seems to have the same energy density(weight per 1000mah) as Li-poly, but is also a safe chemistry like the A123/LiFe/Li-Nano-Phos packs....so it looks like it combines the safety of the A123 with the high discharge rates...seems like a great choice for servo/RX power for gas planes.
I however do not know of anybody besides Duralite that makes these packs....they are $127 for a 2S 3800mah pack with Deans connector & built-in balancing ckt. weight is 8.5oz. (I just ordered 2)

Any other Li-mn guys out there? (BTW Apogee just closed shop)