Nice battery for T-Rex

[Daniel Wee]

I just got hold of one of those Modelite 2600mAh today and did some tests with my stock T-Rex 450XL running Align 25A ESC and 420LF. I had the heli setup for low RPM hover and managed about 18 minutes of hovering before I decided to call it quits. It looks like it will handily do 20 minutes if I really wanted to push it. I am very impressed - looks like this is a nice setup to practice hovering on. Battery was warm at the end of the run but not overly hot. I did the test without the canopy so if you fly with the added weight of the canopy, you may get a little less time.

Now if I can find some way of losing more weight and restoring the CG. With the canopy, the heli is now slightly nose heavy. That canopy is heavy!

Daniel

[Adrianli]

I saw tis batt at Woodlands, used by a fellow Trex flyer.

He was saying that tis pack is good.

However I'm unable to see the performance of the batt, due to mother nature. It rained cats n dogs, therefore no flying.




How is the punch rate? Is it able to hold 20C discharge punch?

[Tele]

yeah I have one as well .. good pack can deliver the punch its rated to 10 C which is 26 amps which is more then enough. put it in my t rex and went for a fly its heavier then the 1700 by about 20-30g. but has the power to boot it when it came to flying 3d

I did not get a full flight time as I took it up high and then lost orientation ( no canopy and all back heli at dusk!! not good!)

my only concern is that nits a 2p pack

cheers doug

[Super-Hornet]

That Sunday I flew my TRex with koon at the top of the hill at Woodland. It was fun! I was using my home pack 3S3P of 1200mAH per cell (total is 3600mAH but old battery). The total weight of the battery is 265g. It flew very well in normal FF. Did not dare to try inverted or any stunts because the battery just velcro tied below the heli and without canopy. What I'm trying to say is that if your battery can sustain high current supply for the TRex, the TRex has no problem carrying around.

Super-Hornet

[Daniel Wee]

Just for the record, my T-Rex 450XL with 420LF motor and the 2600mAh battery with canopy on tips the scale at 752 gm! I'm trying to trim this down while solving the CG problem (too far forward).

Daniel

[ethinger]

Hi Daniel,
possible to get some pictures?
sounds interesting, and where did u get the battery?
Thanks,
Ratha

[Daniel Wee]

I got the batteries from Gabriel through this forum. We met up and he was very nice about it all. The only drawback about this battery is that it's a 3S2P setup and therefore has no balancing header. I don't know how long this happy situation will last. I'm hoping it'll keep me happy for 3 or 4 months at least.

I've attached the photos of the battery as installed on the 450XL. I've also thrown in a couple of photos of my homemade LVD mounted on the tail boom of the T-Rex and another on the boom of the Honey Bee.

Daniel

[Super-Hornet]

Hmmm.... With that kind of battery width, I suspect it may not able to fit inside a conventional mCCPM TRex compartment. Can anyone verify this?

Super-Hornet

[alfer]

It does not have a balancer tab on it. Is that crucial? Would it make the batt last longer? I've been looking at the batts, but I'm kind of concerned if it does not come with the balancer tabs....

[Daniel Wee]

I think parallel cells usually have no balancing tabs. Ie. 3S2P or 4S2P or 2S2P won't have them. There is no way to properly isolate the cells for balancing in this configuration, not without a switch. For 3S1P types they're okay.

I guess the only way to get the most out of this kind of cells would be to make sure to don't over discharge them, which will result in unbalanced cells. And to charge them up conservatively. Basically, avoid extremes.

I manually balance my 3S1P cells but I've not figured out what to do with this new battery yet. We'll see.

Daniel

[Daniel Wee]

Just one more thing, the cells weigh about 180gm with Ultra Deans. This is a bit more than the stated 168gm (without connectors).

Daniel