Eagletree E Logger and A123 progress

[Kiwi]

Well guys I started a new thread on this as the other one is way full of great advise but it covers too much ground so I hope I can keep this one sticking to the subject.

As you know Bill Parry from EagleTree is a great fan of what we are doing here on FG with A123 power systems and flight tests. The guy has been a real help and is an encyclopedia of knowledge and ideas when you need it.

Well my 35% Extra has about 30 flights on it with the DA85, A123 packs (Ign and Flight systems) and I have now come to the conclusion that I just will not fly another 35% or larger model without an E Logger system installed.

I figure it out this way. The plane fully rigged has a value of about $3500 or thereabouts. Maybe a tad more but surely not less. Flying with my two 2300 MaH packs in parallel so I only need one E Logger it gives me so much necessary information that I dont think I would feel comfortable flying again without it installed and working.

I'm sure everyone knows the most fallible aspect of the A123 is when they decide to quit delivering volts and amps they quit. There is NO!!!! slow reduction in voltage. You cant plug in an eight ball tester and see what your pack condition is like. They are either full or empty and unless you have a gas gauge on your packs you cant tell where they are. Thats the only thing I find a very little bit unnerving with them.

After the 30 odd flights on this setup I have found.

10 minute flights average 200 Mah pack drain per flight. (That is total use, both packs so 100 MaH per pack avg for ten minutes.) That is nothing and I know I have ten to twelve flights a day available.

Maximum current draw pulling as hard a 3D as possible is 6.6 amps. I cannot get the plane to pull more than this. Servos Hitec 5945 all round. 4 on aileron, two on elevators, two on rudder.

I have no power system installed and use a 2048 14 Channel 5014 receiver.

Being able to see Mah, Volts, Amps, Cyl Temp, Rpm Max every time I land lets me keep a mental note of where I am with regards to power and what's happening in flight.

When you consider the $100 dollars or so to have all that information at your finger tips every time you take off and land just makes me feel safer in what I'm doing and a whole lot more secure that my inflight system is functioning. If I ever see a massive increase in Mah per flight or a spike in Max amps drawn during the flight then at least I have a heads up on a potential problem and I wont fly until I find it. That to me is a million times better than trying piece the bits back together to see why it happened.

I cant help being a tinkerer in this stuff but I pride myself on the quality of my planes and the fact that they are the safest possible models at any field I take them too. The E Logger is worth every nit picking penny to me.

So why repeat what I already pretty much said in the other thread..

Well I also fly a 50 sized Hirobo heli. It also has the A123 setup in it. Packs made from the same DeWalt pack I got off Ebay. Well 2300 in a heli should be a whooping great amount of battery storage right!!! Well I nearly lost it last week when I landed it and refueled. It had about four tanks through it so say 45 minutes. I went to fire it up again and the gyro light would not flash and no servo response. Switched it on and off and still nothing. I mean hang it that cant be right, battery can not be flat right!!!

Well I hooked up the charger and it failed to boot, low voltage alarm. Crikey, the A123's had turned off, I mean plug in a multimeter and ZERO VOLTS. Not 4, not 3. ZERO!!!!!!!

Now I know from a friend who builds batteries for a living that when this happens (Li-Po's the same) plug them into a NiCd charger at the closest possible voltage setting to your pack or higher. That will reset them or boot them past the low voltage cutoff on most chargers. Well I done that and they kicked in a few minutes later with the correct charger setting. I put 2100 MaH into them plus what ever went in when I re-kicked the cells with the NiCd cycle.

Lesson learned_____ Helis chew a whole lot of battery power and a 50 sized heli on A123 2300 MaH is not good for more than 40 minutes.

So now I am kitting up the Hirobo with my E Logger to see what really goes on in that department but again it proves my point with A123 cells and that is I honestly think there is a need for a fuel gauge on them.

Sure you can count the minutes but that assumes all is well. Why not invest a few coins (you likely saved enough building your own packs anyway) to know what is really happening with your power system on your coveted pride and joy.

Bill you have a convert here and I simply will not fly without some kind of fuel gauge or inflight system monitor again. I used to fly full scale and that instrument scan every few minutes became a part of the everyday flying routine.

I just feel a whole lot happier and safer being able to do the same on my unmanned guided missiles.

If you have any questions or ideas drop Bill a line as the guy is so switched on with this stuff I know he will sort you out with what you need, and you dont need to mortgage the house to go do it. Plus you just might keep that 40% pride and joy in the shed for a whole lot more years to come. Its a lot more fruitful selling an airplane in one piece than selling the left overs.

I know its not a cure for all the gremlins we fight to stay aloft every day but it sure as heck is a 100% better than not knowing anything.

Thought I would share my findings so far and look forward to any responses, questions and comments guys.

[Hammbone]

What switch are you using on your 35%er?

Jim

[Kiwi]

Unplug the battery Deans plug. No switches, absolutely bullet proof but I will be fitting a 14MZ Power Expander this week for two reasons.

One is it gives me a simple switching system after the Eagletree E logger so I can leave the unit on al day and read the gas tank any time and know its right. The unit burns about as much as a wrist watch so there is no draw at all to be worried about.

Second is the servos squeal like pigs with the system direct as it is and that goes away with the Expander. There is no servo binding as my static current draw with power on and radio on is 100 MaH and I have never ever been able to get anything better than that.

The heli is the standard Futaba heavy Duty switch setup but deans on the battery connection.

[Hammbone]

How does the Eagle Tree system get hooked up to your system? Is the current flowing through it?

Jim

[Hammbone]

How is the current going into your 5014 rx now? I know the deans plug is not going into the rx.

Jim

[Kiwi]

Jim.

Two A123 packs with a Y cable into the male deans built into the E Logger. Then I built a custom three cable deans to JR plug with heavy duty servo cable. That feeds directly into the Rx as I have some 4 spare pins.

System is bullet proof as the current goes through the E Logger but the E Logger is a simple buss and rated at 100 amps cont.

If you want a photo I can get one in the morning.

[Hammbone]

Do you have one jr plug going into the rx, or four?

How will you hook up the Eagle Tree with the Power Expander?

Thanks, Jim

[Kiwi]

OK I have three cables out of the E Logger made in a multi Y type cable. but looking at the data and seeing the maximum current draw at 6.6 amps I can easily reduce that to two and have a ton of spare capacity.

Now to hook up the PEX 14 board I will do much the same but make a Y cable out of the E Logger and into each side of the PEX. I will use heavy duty spaghetti silicone wire and thats good for 20 or more amps per cable. That way the E Logger stays in circuit for the entire duration of the day or until I pop the canopy and unplug it. That way I have my all day fuel gauge. I doubt I will ever need to recharge during a day as ten flights is more then the darned pilot can handle without the need for a nerve settling beer.

But thats my plan. Simplicity at its best but I think its very very safe.

[Hammbone]

Doesn't the E Logger remember the mah used even if it is turned off?
I was looking at their website today and that's what it seemed to imply.

Jim

[Kiwi]

Jim,

So far I have not seen it do that but man there are still things I'm learning as I keep changing the setup.

I think it remembers the MaH total on the data logger but not on the LED display. Every time I turn it off it goes back to zero but if I have say three sessions logged on it the total displays on the computer. That is it keeps counting up. I really dont intend to take the PC with me to the field but I will call Bill and see if there is a way to hold the MAH info in some sort of non volatile memory that requires data base clean out or something to reset it to zero.

However leaving it in the loop for the day will display all the maximums you have achieved. RPM, AMPS, WATTS, VOLTS. The only two I really want to see are max amps and total MAH. Live voltage data is OK but again because the A123 shuts off without being nice about it I dont lay too much credence on volts at all.

[Hammbone]

O.K., well no big deal. We can just do what you are doing and leave the E Logger on all day.
I'm liking this idea, and I think I'll order me an E Logger today and try it out.
I am in the process of switching all of my planes over to A123's, so the ability to have a "fuel guage" for the batteries sounds like a good thing to me. The other features are all cool as well.

Thanks, Jim

[krayzc]

kewl...