Newbie needs help with Lipo battery choice

[Aloha Flyer]

Greetings:
Have a TREX 450SE with TP2100 11.1v. Want to add more flight time and a little more punch. Just received a TP4200 14.8v in the mail----way too big... will be sending it back. Just ordered a TP2650 14.8v today.
Questions:
1. Any advantage with the increased voltage?
2. Any damages with the increase voltage?
3. Any changes need to be made to the heli using 14.8v
Thanks....Just found this site today ....excellent!

[zagidave]

i think the size of packs you are considering may be tooo big for a trex.
its only a small heli and if you double the weight of the pack it will suffer from obbeisity :(

second thing to consider is your motor / esc designed to run a 4 cell lipo?
also have heard people using 4cells usually have a seperate bec.

just my 2 cents hope it helps

[Aloha Flyer]

Thanks again for your input.
The size and weight point is very well taken. However, check the actual size and weight from TP:
1. TP2100-3S 2100 mAh, 3 cells (11.1V)- 34mm x 100mm x 20mm @142gm
2. TP2650-4S2P 2650 mAh, 4 cells (14.8V)- 34mm x 66mm x 48mm @220gm
The size difference of the 2650 is such that it is shorter but taller than the 2100. If the pack was installed lower to account for the extra 24mm of height or....placed on it's side where the base would be 48mm (TREX frame width is 40mm), it could possibly fit- barring 4mm of battery sticking out of each side. In this case only 14mm of height would need to be compensated for.
As for the weight...the difference would be 78gm.
Question- Would the dimensions of the 2650 change the flight characteristics?
Question- Does anyone know if my standard TREX 450SE 430L 3550KV motor and BL-35G ESC can handle a 4cell lipo @14.8v?
Thanks

[Aloha Flyer]

Hey Guys:
Just researched my Question- Does anyone know if my standard TREX 450SE 430L 3550KV motor and BL-35G ESC can handle a 4cell lipo @14.8v?

Turns out the 430L can handle 7.4v to 14.8v and the BL-35G ESC can handle input voltages: 5.5V~16.8V. Supporting battery types: Li-poly 2~4 cells.

I still need guidance to the Question- Would the dimensions of the 2650 change the flight characteristics?

Appreciate your input

[Rick Rotorhead]

This question is useful for me too as I'm just about to purchase my first Trex gear.
I want longer flights than 8 mins!!! so a 2600 sounds good to me. Also 4s with stock parts wooohoo - what pinion for that set up then Bob?

[Aloha Flyer]

It's good to see some interest in this topic.

Anyway, I expect some lethargy in flight that could be masked by the increase in power. I will report by the end of the week after a test flight. Would be interested in knowing if a pinion change will be beneficial.

Appreciate your input

[zagidave]

any test results yet .........would be interested in your findings :glasses:

[Aloha Flyer]

Hey gang:
Just received 2650 Lipo pack today. Had the hobby shop put on some deans for me. Will mount and charge the battery tonight. Will test fly tomorrow am. Bought some 7gm self adhesive lead in case there are balance issues. There was a slight forward tip on pre-mount (after canopy placement).

Till tomorrow.

[dodgey]

just a pointer from my experience - 8-10 min flights (that's what I get with 3s 2100 Mah - fff and mild acro) are not so bad if you buy a handful of packs. In fact - I find 8 to 10 mins is the most I want to fly without having a short break. I've gone down the multi pack route for duration. The good thing about this is you can go fly without taking any field chargers with you as you just take a bag full of packs :cool:

Be very interesting to hear how you get on with 4s though.. I think you'll definately notic e the power over the weight! - I can tell a significant difference when I put a fresh pack on my bird, let alone going up by 3.7v!

[Aloha Flyer]

Hey guys
Mixed feeling only because I am a newbee. The canopy fit was tight but do-able. I needed to add 28gm (4X7gm Lead) to the rear tail wing to balance. About 250gm would be added to the dry weight of the helicopter or 108gm MORE than the 2100 11.1v.

Now the test flight. Mild wind this am in Hawaii. The tone of the motor and blades was slightly higher. The response of the bird was greater but their was more compensation for the weight. I had difficulty controling the tail- kept wanting to swing right. Adjusted the gyro and trim but did not feel comfortable taking it higher than 8ft. I'm sure if I were more familar with the gyro and transmitter settings, I could do better. You can see how GREEN Iam.

With my present level of experience, I am not ready for the extra weight or power. If I had a pro tinker with my setup it would definitely work better for me. Unfortunately I don't have the access. If you are a newbee with better knowledge of the electronics, I would still not go beyond 2100 14.8v. The extra weight will slow overall response for this size bird.

So what will I do? For now, I will get a total of 3 -2100 11.1v packs install for easy access (velcro & rubberbands) and swap out every ten minutes with a few minutes of rest inbetween. I already have a motor heatsink on order to help keep things cool. Once I gain knowlegde/experience, I will return to 14.8v BUT STILL AT A 2100mah charge. The 2650 @ 14.8v can go into a future Trex 600.

Thanks again for all your interest and comments.