Monster Motor Battery Selection

[Mr.Grinch]

I recently picked up a pair of FT Monster motors and intend to (hopefully) build a Monster sized plane for FF24. I was considering the Monster Cruiser from the 400th episode or an oversized Guinea. I'd like to get the plane up to cruise around for a check flight, then put it up into combat. Since this would be far larger than anything I have previously built, I do not currently have appropriate batteries for the project.

I know there is a great amount of flexibility or variability in a project like this, but considering that I am doing this as a FF project and not for year round, long term, high speed or long duration flying, what should I be looking for in a battery set up?

I'm anticipating buying a pair of 6S, but would something in the 5-6k mAh capacity be enough do I need to be in the 10k+ range? I know I can calculate out what the current draw of the motor pair would be and what XXX capacity would provide for flight time, but I'm more asking for real world experience, rather than just going by the numbers.

 

[Horseman3381]

I have a number of monster motors that I have used various planes including a 180% sea duck, 300% mini corsair, and 180% Ben Harber's Stearman.

For a single monster motor I use either a 4000mah or 6000 mah battery. I don't like to fly my batteries to less than 40%, so with that I get around 4 min flights with the 4000mah and 6 min on the 6000 mah. That is with a casual cruising around, nothing fancy. If you are going to be doing a lot of high speed flying, that will reduce the time. The is per motor as I used 2 batteries in the sea duck.

As a side note, make sure that you mount the esc in a place where it gets good ventilation. The FT 80A esc tends to get hotter than would be expected when running the monster motors, and I have had issues when I mounted it in a not very well vented area.

Also watch out for over-proping. I believe I run a 14x6 2 blade and 13x6 3 blade. You can go to x8 and the motor will be pretty warm after the flight. Anything bigger and the motor will get excessively hot.

Hope this helps.

 

[Mr.Grinch]

Thanks, it's a good jumping off point. I am surprised by your prop size, I saw the guy flying the biplane off two monsters and launching other small planes off the top running a 16x10x3. The recommended props are 16"-18" on 6S, but I'm definitely open to real world experience over a data sheet. I'll probably start off with a pair of 6K's and run in parallel for a twin to start off with. I'll move larger if I need to down the road, but since this will just be an experiment next FF, it should be an OK start.

I'll just cruise around mostly, be an easy target in combat if I can get it all together. I'll probably get a set of Turnigy Graphene or Liperion to start. I normally go with the GensAce, but at almost double the cost, I'm a little hesitant to spend the extra right off the bat.

 

[Horseman3381]

I first tried 16x8x3 props on the motor because that is what they mentioned in one of the videos, but you couldn't even touch the motors, let alone hold on to them they were so hot.

A more recent video they said they were using some 13x8 or 13x10 HQ props. I had ordered them and went to test them on my Sea Duck, however I managed to crash the plane before I could land and an check the motor temp (Crash not related to the prop, it was because of g-lock on the elevator).

My 6s4000 are Turnigy graphene, and they work good.