Litium Ions...A good investment?

[Al Czervik]

This past weekend I was flying my Funtana 90 around with Futaba 9252's all the way around with a 9151 on the rudder and a 3151 on the throttle. After about three flights or so my Nicad battery is ready to be charged. I don't remember the mah rating on the battery but the point I'm getting at is I'm spending too much time charging.

I'm considering making the investment in some Fromeco Relions along with the regulators, charger, voltage checker and so on. With my next plane to go together being a QQ 73 Yak that will also require some serious juice on the servos, I thought this would be a good investment. A really big NiCad is almost the same amount of money from what I can tell.

Another problem I just realized with the setup in my Funtana 90 is that my Futaba 9252's only operate at 4.8v!!! Considering the voltage regulators are adjustable, can I run it at 4.9v through the regulators in this situation due to the servos I'm using? Will this fry the system? The lowest the regulators can take the voltage is 4.9 from what it says.

Any advice would be appeciated!

-Brad

[TheTank]

The fromeco setup is well worth the investment. I have one 2400mah pack and reg in my F90, and I can fly all weekend (probably two weekends without charging). I am not familiar with Futaba servos, but are you sure all they are rated for is 4.8volts? I have been running my Futaba 3010a at 6volts in my F90 (for which they are rated) and they are lower end servos, for 2 years with out problems. I know if you go over 6 volts, there have been some problems. I would check it out on Futabas site to check, because I am pretty sure they can handle the voltage... but dont take my word for it.

[SleepyC]

Lit Ions are INSANE.
Best investment you can make if you already have a good light plane.

I get easily 8 - 10 (10 - 15 min) flights on my 33%er with 1 4800 pack on the servos/rec, and 1 2400 on my ignition.

I regulate at 6V so I'm not sure about 4.9

But without a doubt, once you go lit ion, you won't go back to NICAD o NIMH.

[Vic3D]

I have a 4,800 on my 260, with 9 servos and I get about 10-12 flights on it.

I had a 2,400 once on an F90 and it gave me power for the whole weekend and still left over for another day or two.

[All Thumbs]

I can tell you from experience, you won't ever go back. The only thing that needs to be reminded here is that if you run two batteries, switches and regulators, that you have to really be adamant about setting the regulators to exactly the same or you'll get the system drawing from the battery/regulator that has the most current draw first. There are regulators that have the Smart-Fly Bat Share system built right in them. Of course, they're Smart-Fly products. Or, you can go with the Smart-Fly Bat Share itself. This reduces the need from two regulators to one. Which ever setup you go with, you'll be totally amazed and satisified with the Fromeco Li-Ion batteries.

[toprudder]

FWIW, If you have a fully charged 4 cell Nicad pack, you might see 5.5v or more when you first turn on. I don't know about the voltage limitation of the Futaba 9252, but I would not think you would have a problem running them at 5.5v or less.

[Al Czervik]

Giants,

Thanks for the useful advice. This site is the best!

-Brad

[Al Czervik]

One other question or two here. I've been speaking with a Don of "Don's Hobbies" and he's mentioned using a certain off/on switch where I can hook in the voltage meter to check the levels w/o taking off the canopy.

Considering the bigger you go, the bigger the investment, he said it was good to check the voltage before every flight. Do a lot of you guys practice this? It sounds like a good idea...all of my planes have crashed due to stupid sh*t more so than dumb thumbing and I'm working towards being more careful with EVERYTHING before each flight.

And would a redundant battery be overkill on a Funtana 90? I don't think it would be that much more weight and can you be too safe? I've got the money so why not?

[SleepyC]

Most switches that have a charge jack on them you cn plug a voltage checker into and read the battery.
I use the Fromeco 8-ball before every flight.
I mean 30 extra seconds can save your plane... totally worth it!

[All Thumbs]

Probably not necessary for some, but the picture below may help others. This is the system with the BatShare and without the BatShare. Fromeco batteries, Smart-Fly Super Switches, Smart-Fly BatShare, Fromeco Regulator:
Completed Aero Works Plane 056.jpg

Completed Aero Works Plane 058.jpg

Completed Aero Works Plane 019.jpg

[Pale Rider]

I have 2 50cc planes..one with 3 2400 Fromeco's and the other with 3 1400 NIMH packs..The Liions are definitley lighter with wayy more capacity but they are more expensive and although not a big deal, you have regulators which add to the total wiring..If you fly a lot of flights in a single day (more than 8) then the Liion is the ticket cause you can easily get 12-14 flights..at least I do before needing a re-charge..
I usually fly after work so the most flights I can get in is usually 6-7 13 min flights..after 7 the packs are down to about 6.1v under a 1/2a load..my 1400 nimh setup is 2oz's more than the liion setup but I really dont use the extra capacity of the liions so for me there isnt a big advantage except the liions dont discharge when not being used like Nimh's do..Ive read that the constant voltage of 6v is a plus over nimh's but honestly I cant tell the difference between 6.5v vs 6.2 but I ain't as good as you guys!

If you chose Li-ion's then DEFINITELY go with Fromeco..Kurt and Mike give great support.

Whatever setup you choose definitely check the voltage before each flight..it only takes a few seconds.