Der Goetz

My Feedback: (9)

Heya guys!

I started out with Alfa's and smaller ARFs, and bought 8 2100 3s 20 packs to run the small outrunners.
I had that many packs since some of my planes (Scorpio Mosquito and others) were multi-engine.
I always ran the packs single though.

Then I got into glow conversion and bought the HL Cub. Put a AXI 4120 in it and took 4 of my 2100-3s packs.

I soldered a harness to run them in 2s2p. Making it 4200-2p6s in theory.
Perfect for my motor/prop/plane combo and it runs just fine.

Now I got a call from my dad who told me that he is sending me a report from a German magazine stating that this ruins the packs.
At my LHS the week before I was told that the last packs in line pretty much suffer and wither away.

Any experience with that? Is my dream of running my bigger motors on packs I already own..just a dream??

Any advice, and I mean advice from people who actually tried the same thing and had either postive or negative results.

Thank you,

Goetz

A10FLYR

My Feedback: (1)

I have never heard of that but it could be possible I guess. For the 4120 I made a harness to make up a 3P6S power pack. Works well.

Edit....I just checked out the cub...48" span? The 6S2P should work for Ya! Watch the current draw tho.

Der Goetz

My Feedback: (9)

Just got the German Magazine's article and here is (summed 3 pages up) what they have to say:

They argue that GOOD packs are matched. The three cells in a pack are matched in the sense that they have the same capacity exactly.
So, if you get 8 minutes flight time and all of a sudden the battery voltage drops you can be assured that no harm was done since all three cells pretty reached their max. running time at the same time.

Now, if you take two packs and run them in series, you run two packs that by themselves are matched, but they are NOT matched to each other. So, by the time the voltage drops you are running the lesser/inferior pack into the ground.
They say that from their experience you ruin your packs by running them in series.

I wanted to run 9 packs. 3 in series, and 3 strings in parallel.
My chances of one or more packs getting completely sucked dry in this config once I reach the max light time is immense.
Man. Graupner is about to release a product that will monitor ALL packs in your plane and get this, pull back the throttle (the devicewill sit between receiver and controller) to match the weakest pack.

Looks like I am hosed.

A10FLYR

My Feedback: (1)

Using that logic we're all hosed if we use anything over 3 cells! I've gone thru quite a few packs but then I tend to abuse them by pulling max amps and overheating. I can't wait till this gets worked out.

Der Goetz

My Feedback: (9)

we are discussing this at [link]http://www.rcgroups.com/forums/showthread.php?t=514028#post5433655[/link]