Pete737

Guys I got a good deal on two hobbico LiFe source batteries.

2 x 2100 mah 6.6v 10c 13wh running on a powersqfe 1221.

This is okay for an f15 with 2-8711's and 7-8411's correct?

Pete

KC36330

i have never been a fan of small batteries in a mid/large size jet.......

Pete737

Kc I previosly flew my f -18 from 2 x 2400 nihm. I thought LiFe chemistry being newer would not have a problem at 2100. Advice?

Shaun Evans

Pete,

I think those are just fine on what you're flying. The draw is considerably less than what people think, and with two on a powersafe...

Vincent

My Feedback: (61)

No problem at all, i run (2) A123 6.6v 2300mah packs in everything i own, also running a JR1221rx. I believe the 1222 is the power safe rx.
Vin...

quist

My Feedback: (198)

You will be able to fly all day with 2 2100 mah batts as long as you have a good radio setup in your jet. This is what I was using in my Ultralightning with 8 8711 servos. I used less than 300 mah per flight.

Dr Honda

My Feedback: (4)

I run 2x 2200 mah packs... and after 4 flights, and some messing around on the ground... I only put 400 ma back into each pack at the end of the day.

To be safe... you could hook up a power meter to make sure you aren't drawing too much. (Hanger 9 makes a nice little meter)

FYI... This is on a falcon with 10 servos, and there is a third battery pack for my engine ECU.

KC36330

200 mAh per flight??? what kind of flight time???? my Tornado is the smallest jet i've got, it has a single 2300 LiFe battery, it uses 350 ish per flight, there is no binding of any control surface and i don't bang the sticks around so i can't imagine a flight using half that.

FILE IFR

Well, that's 100 Milliamps per flight... and with 10 servos? I know you're an electrinics wiz, but to me, that's tough to swallow.

.... Are you doing just take-offs and landings per flight??

Harley Condra

My Feedback: (4)

Using two batteries gives you twice the Ma capacity, and cuts the impedance in half.
You should be good to go.

I use two 2600 Ma ThunderPower Pro Lite V2 Lipo's in my KingCat. It has nine 8411's, and two 351's, a JR 1221 Rx, two Fromeco Sahara voltage regulators, a Fromeco Wolverine dual switch.
I usually do four flights without thinking about charging. I hit them at 2.6 amps, and in about 20 minutes, they are at full charge.
I use a ThunderPower 5000 Ma for the ECU battery.

My Ultra Bandit has two 4000 Ma Spektrum LiPos, two 10 Amp Spektrum regulators and switches, and a JR 1222 Powersafe receiver. It aso has eight 8611A's, and two 351's.
I don't know how many flights it will safely get before charging, but intend to find out soon.

I don't see the time spent charging as a problem.

FenderBean

Life batteries are very dense and are great I plan on using them on my next jet. Less weight than a123s but they are not high discharge, which for receiver use ia fine. It all depends on how many servos you have, my giant plane had more servos than my plane.

afterburner

My Feedback: (18)

KC, have you put a meter on the plane to see what the actual current draw is at idle and then when you peg all the control surfaces to max throw? I have put three flights on my reaction which works out to about fifteen minutes of flying and say another seven to eight minutes on the ground and put back about 300ma combined between the two batteries I have in the plane.

Marty

KC36330

Marty,

i use that little hangar 9 current meter on each servo during setup only to make sure there isn't any binding of the control surfaces throughout their travel.

now my Reaction 54 i haven't checked how much is put back in the battery (it has just one Duralite on the RX and i use the Duralite charger), i just got it a few weeks ago and last weekend was the first time i had to take it out and only got 6 flights on it but it has less servos and it only goes 7min with the left stick in the FUN position so i would expect it to use less mAh per flight then the Tornado with 10 servos and 10 min flight.

Dr Honda

My Feedback: (4)

My timer is set to 4.5 minutes.... so there is a couple minutes on the ground after I start... and I have about a minute to land after the timer beeps. Realistically... it's a 5 to 5.5 minute flight. (I don't start my timer until I get ready to take off)

The other thing I was thinking about is that I didn't go overkill on the servos. SO... if you have monster metal gear, high torque servos... you will be pulling more than me. So if I'm pulling 200 per, and you are pulling 350 per... that would be right with bigger servos.

What I have:

Ailerons: 2x JR digital about 90 oz/in
Flaps: 2x Futaba Digital 58 oz/in
Nose gear: Futaba standard. 48 oz/in
breaks: Tower Pro Micro 28 oz/in
Rudder: 2x HS-80 mini about 40 oz/in
Elevator: 2x Power HD mini metal gear 48 oz/in

I know to some... the servos listed above sound weak... but none of the control surfaces are very big... and I'm not yanking the sticks hard. (I don't want to break the wing. lol) So... they should be fine.

KC36330

I've got the Modellbau servo pacakge in mine, all analog servos, the only exception is i had one bad servo so used a Futaba 3010 on steering, JR R1221 receiver. P-60SE gives me a 10 min in flight on the 80oz of fuel and i've only sucked her dry and flamed out a few times but it's quiet low when i land most of the time.

Dr Honda

My Feedback: (4)

I'm newly waivered... so my timer is set short. (don't want to try a dead stick yet) I could probably go out to a 7 minute flight since I land with about 15 ~ 20 Oz left in the tank. BUT... your longer flights would explain the power difference.

Regardless, I think you are safe for 4 or 5 flights between charges.

megafly

You are good to go I use two A123 2.00mAh in almost all my planes includind my extra 42%. I can make like 5 flights before recharging, and with A123 you can recharge them in 10 minutes!
I have this setup in my Tornado and I can fly all day, I've made 8 flights before recharging, and the charger putted like 1300mAh in each battery.
I'm bulding a Feibao Panther with this setup.
I like very much the A123 batteries.

Regards

KC36330

i fly till the voltage drops below 6.6, typically 5 flights, i have got 6 but it's not often.

afterburner

My Feedback: (18)

KC,
I think it's a good idea to put the meter on when the plane is complete and powered up to get a cumulative reading. You may have adjusted things later on or at the field after the maiden that could be binding and since your Tornado is using all analogs, you don't here the whining of digitals that sometimes(not always)means a higher current pull. Just a thought.

Marty

jetflyr

If in deed you fly until it drops below 6.6 you are looking for a smoking hole! The discharge curve on LiFe chemistry gives basically a 90-degree elbow drop off.
DO NOT let it get below 6.6, the airplane you save will be your own!
Greg

KC36330

the drop off is at 6.4v and a fair taper from 6.6 to 6.5 you're safe flying down to 6.6, when you see it drop below that, charge.

FenderBean

Lipos are the same but I think they say stop flying at 6.4

megafly

Well, on a new plane I usually fly once, and recharge, so you know how manny mAh your plane has consumed. After that you will know how manny flighs you can do.

KC36330

2s LiPo is stop fly at 6.9

FenderBean

I was talking about the 90deg drop. I stop at 7.0-7.1 volts myself.