A little Lipo concern

[Raydee]

Has anyone ran a Eagle tree data logger on their 550 to see what the amp draw and battery voltage looks like? I am concerned that 2100mah or 2200mah packs at 50-55 amps are going to get overworked and only last half or less of what they can. How hot are the packs getting after a full 4 min flight?

Bob I know you have upgraded your motor to a 600 size? Are you still running 2200mah 25c cells? How hot are they getting after a flight. I run Electric boats and I know that heli's don't pull the same amount of amps that the boats pull but I still like to go by the 70-80% rule meaning if I know my boats are going to pull 70 amps I like to have a 100amp battery to still have the 30% buffer and keep the voltage up and the cells below 125*. I have seen good cells that were pushed at thier c rating only last 20 charges before they had noticable drop off and don't want to go through the same thing.

A bone stock 550 might be ok with small cells but once you put a motor with more KV in it I think i would start to be concerned for sure. So if anyone has any eagle tree data to share that would be great.

[arclite5]

~20A hover, ~65A 3D.

Depends on your HS and flying.

-Kyle

[Finless]

No when i upgraded to the 600+ motor I started using 2500ma 6S packs. No issues other than only 4 minutes flight time.

Bob

[Raydee]

Bob how hot do your packs run after a 4 min flight with the 600+ motor?

[Finless]

About 125F.... in that area. These are FP EVO25 25C packs and anything else your mileage will vary A LOT I am sure...

Bob

[Raydee]

That isn't bad at all. I was expecting them to be a bit higher in temp. I will most likely get the FP 25c 2500mah packs or the Poly RC 25c packs. I run the Poly RC in all my boats and they are great cells. No junk Lipo's in this house ;)

[Finless]

ARe you going to power this ship up? If so consider 3300's and moding the frame. If your not hot 3D and/or sticking with stock motor then these will be great. Otherwise a powered up machine will get you 4 minutes max on 2500

bob

[Raydee]

I am not a hard 3D flyer but I am also not a beginner so I guess middle of the raod is where I would like to be for now. I want enough power to get me out of a jam but not so much that I am just wasting energy. I like the idea of the 600+ motor but will that be too much? Run time isn't a big deal, I can live with 4 minute flights.

[Finless]

Understand that a 2100 pack that can deliver 25C and a 3300 pack that can deliver 25C will give the same power output (at least at first). Flight time and power throughout the flight are what larger packs are about NOT power output.

Thus a 25C 6S pack rated at 25C discharge will give the same power output (at first until it discharges) than a 3300 pack at 25C discharge....

So the reason people are looking at larger packs is to get longer flight time NOT more power.

Bob

[Raydee]

I was talking about motor power. I know the stock motor is lower on kv compared the thr 600+ so with the 600+ the headspeed will be higher to help get me out of a jam. I also understand that the higher the KV the higher the amp draw and the lower the run time. I would gladly sacrafice a little run time to have a heli that I know will get out of its own way when it needs to. As long as the 25c 2500mah packs stay below 135-140* during the whole 4 min flight then I will be happy. Right now I run 4s2p3300mah Poly RC packs in my boats and the cells barely make it over 100* most runs. My boats pull 90 amps in most cases and peak at about 120-125 during the launch. I tried running them at 4s1p3300mah and there was no way they would survive more than 20 charges before they would be shot.

So far with everything I have read about the heli the only thing I don't like is the battery setup. I understand the concept of being able to use TREX cells and not having to buy new cells but at the same time its the limiting factor if you want to fly HARD 3D. I never used a outrunner motor and my guess is they are more efficient than inrunner's? They must be to be able to run a 600 size motor on 6s and only pull around 60 amps.

Any way you look at it I am buying one and when mods and new frames come out for larger cells then I will upgrade as I go.....its all a money pit anyway right :smokin: