haasjj

I know 185grams is close to what I ran before for batteries. I am needing some new batteries for my Trex and I was planning on using a Flight Power 4 cell 2500mah 25c battery. The battery weighs about 265 grams, is this to heavy for a TRex 450??

How would the 2170 be at 222 grams???

rzarikian

http://www.rcuniverse.com/forum/m_7835947/tm.htm There ya go!

Anyway, that is just too heavy. Why do you need a 2500 mAh 4s battery. remember that with higher voltage, less mAh are needed to achieve the same wattage so if your going with a 4 cell lipo the you DON'T need that much mAh, even a 1800mAh 4s lipo has more punch than a 2200mAh 3s lipo.

So now the question I ask you: is a 2500mAh 4s lipo really going to last that much longer on a 450? think of it this way: The more weight you put on it the more weight the motor has to lift thus consuming more power. So even though a bigger battery packs more punch, that extra punch is needed to lift the extra weight, and your t-rex will be very nose heavy and will feel very heavy overall, making a crappy flyer out of it. Don't go over 200g, stick with the recommended weight.

If you really want a 4s lipo then the the biggest 4s lipo I would use is the outrage 1800mAh which weighs 200g, but still has more punch than a 2200mAh 3s. The best thing (if you have the bank) is to get two 2200mAh 3s and if your in a hurry just charge them in parallel at the same time as a 6 cell 2200mAh lipo. that way you double flight time

darthdrk

Another thought is people are putting almost 300gram scale bodies on their t-rexes and using a 4s pack (thats over 500grams) . People are going wrong alot of times by wanting to prolong their flights. Sometimes its a good thing not to fly the heli for extended durations. I think 20min flight times are nice but can be hard on batteries, motors and electronics.

haasjj

You both make some good points, and I will explain why I was looking at the 4s 2500mah.

well I'll just delete that comment and eat some of my words. Is there anyone who has used a heavier battery in a Trex 450 instead of just repeating what someone else wrote.


darthdrk

I agree with you about scale application but since when you do that you are no longer looking for a highly mobile machine but instead looking for a nice looking and scale flying machine that it is the time to put on a heavier battery. To use that heavy of a battery a try to extend the flight times just doesn't make sense though.
I have never flown anything for more than about 10min at a time and I can't see wanting to fly a Trex for 20 min.

haasjj

Has anyone used a heavier battery in their Trex 450?? Like around 265 grams.?

haasjj

No one has used a heavier battery in a 450 SE

rzarikian

Actually I've been searching around and I found people who are putting 280g worth of A123 cells to their 450. But they where used for mild sport flying, not 3D. That setup would be great if you're a biginner sice it will give balance to your heli and charge time would be around 15min. but you sacrifice weight which is not good for 3D.

Flying Geezer

My Feedback: (14)

You'll actually get more flying time with a 3S pack than a 4S pack of the same size. Anytime you increase the voltage you increase the drain rate on the pack.

If you are looking for longer flights you'll do best getting larger 3S packs.

haasjj

Where in my post did I say I wanted longer flight times my question was about running a heavier battery to be specific a 4cell 2500mah. I know how to increase flight time its not larger packs its higher Milli amp packs which yes that does generally mean that they are larger but not necessarily. You should be getting the same flight times using a 3s or 4s pack as long as the two packs have the same Milli amp rating, maybe slightly less because of the extra weight but a static test should be almost identical flight times. There is more to it than that but just a a simple rule.

rzarikian

wait.. you're saying that with for example a 2500mAh 4s battery you will achieve the same flight time than with a 2500mAh 3s??? not taking into account the weight? Are you sure? and Why?