philsmein

I have 2 thunder power V2 extreme batteries 11.1 2200mah. I run these batteries in a Typhoon 2 with a park 480 1020 kv and castle creations 35esc. My question is I run the plane about 12 minutes. When I charge the batteries on my triton jr it shows at the end of the charge it puts about 1700 mah back into the battery pack. Is this bad considering im running the battery down where it only has 500 mah left in the pack? Also what is the approximate run time I should expect in this plane. Can I push it a few more minutes or am I going to toast the batteries. The Triton Jr also takes 90 minutes to charge the battery back up?? I thought these packs only took 40 minutes to charge. Im confused......

jzrf6c

First off are you charging at 1C? If not you should and that will take about 90 minutes to put 1700 ma back in the battery. As far as how far to discharge, its a function of the voltage left in the battery. You don't want to go below the cutoff voltage of about 3 volts per cell. Your ESC should shut off in time to not damage the battery. As to how much more you can fly, that's up to you and how you fly. It's a matter of throttle management.

TallDoode

I run a similar sized plane and use SkyShark RC 2100 mAH batteries. I set my timer at 8 minutes of "basic" flying - 75% - 85% throttle (not 3D). After 8 minutes, I charge for about 60 minutes regardless of the charger I use (I have three chargers). If I fly for 10 - 12 minutes, I charge for almost 90. I use the same batteries for my T-Rex 450 and get about 8 minutes of fly time (no 3D) and charge for about 70 minutes.

Bottom line, what you are saying sounds just about what I have experienced as well which is what I was told to expect by my LHS.

Happy flying,

dave

tankertoad

Dave - How do you like those skyshark batteries? I'm building a Fliton Edge 540 freestyle with a similar set up to the one that was built/reviewed here on RCU. It looks like they only have 15C discharge rate, which I'm wondering is going to be enough for 3D. I'm either going to go with two 3s lipos or 1 5s lipo and prop it bigger. Both set-ups were reviewed on RCU. This is my first e-conversion. I'm also wondering if you can connect less expensive batteries with a parallel adapter to get the MaH rating up to where you need it, or do you have to just buy the big capacity batteries to get the desired effect?
-Matt

philsmein

Thanks for the help guys. Sounds like 90 minutes to charge puts back about 1850 back into my 2200 pack. What if I let the charger put back in 2000 mah. Do you think thats cutting it too close?

TallDoode

Matt - I actually love the SkyShark RC batteries. They are about 40% cheaper than the Thunder Power and as near as I can tell the performance is pretty close. If I was flying a heli doing extreme 3D i might want the Thunder Power series, but for my flying the SkyShark are fine. They are 20C btw, not 15C. I have been using SkyShark almost exclusively for about 18 months and have never, ever had a problem. For what its worth, we have a SuperFly each year (www.lasvegassuperfly.com) and the SkyShark people have been sponsors for the last two years. They come up and set up a booth and sell thier stuff so I always stock up when I see them. The few times I have had to email or call for support they have been very quick to reply. All in all, a great experience.

As for running parallel - I do that on my Stampede electric truck. I take 2x 2100mAH batteries in parallel for 4000 mAH and it rocks. Never tried it on a plane. Guy in my flying club does it on his 600 size Heli and it works.

Philsmein - I let the charger tell me when it is done so not sure how to answer your question on the 2000mAH.

Cheers,

dave

tankertoad

Thanks for the info. I had a hard time coming to terms with spending nearly half what I have in my 50cc gasser on a .60 size electric conversion that only runs for 8 min, so budget options are the way to go for me. I am going to "experiment" an RC Smart conversion (480kv/80A ESC/ 2x11.1 5000mah - $275) from eBay. I'll start a thread up here once the parts arrive and see what kind of performance I can get out of it. If it proves to be a wash on my Fliton Edge, I can easily put it in a lighter plane for 3D performance and go with the Skyshark .75 conversion (my back up option), which looks like a good deal, especially after your testimony. Of course, one could always spend over $500 converting a 5 lb model to electric...nah.

kid chuckles

I run 2- 2100 lipo Thunder Power batts. in parelell to get 4200mah. I have had no problems at all and get about 18-20min. using a 25 motor and a 60 amp. Castle ESC. Run three HI Tec 225mg's and one JR48. Run this setup on an Eratix 63" wing span. around 6lbs. Very lite plane. It flys great just wish there was some way of recharging quicker. Someon could make alot of money figuring out how to recharge in 10 min or so lol. Or making a 2100 lipo that costs under 30.00 and works. That would be a money making deal lol. This plane also has a setup for a 32 size motor but does not need it the 25 is more than enough for this setup and size.

tankertoad

That Eratix looks like a nice plane. If I didn't already have the Fliton Edge 540 Freestyle, I would have gone with the Eratix. What size prop are you using? 6lbs seems heavy, but that must be with both batteries. I'm glad to hear you are getting good performance in this weight range. The specs on the motor combo I'm getting didn't seem too promising at first, but I think I'll get better performance than what they (RC Smart) are telling me.
As far as batts go, I'm watching this A123 revolution with great interest. I'm not ready to ditch my lipos just yet, but it seems we may have a little better alternative.

Witterings

Philsmein,
Doesn't your charged have a cut out when the batteries fully charged ????????? If not might be worth getting a decent one with a balancer as well if you're going to be in the hobby for a while.
What I tend to do is fly the plane for lets say 8 mins, when I land I hold the plane and the use the throttle as though I was flying it and see how long the battery last after that. If I get another 3 minutes no the next flight I'd increase the next flight by 2 minute and the do the same exercise again so I work out nearly exactly how long I'll get but then cut it short by approx a minute in case you need to go around again / have a bad approach and as you're batteries get older their flight time will decrease.

kid chuckles

The Eratix may not weigh 6lbs. it is very light and I have not scaled it. The batteries i am using I have been using for more than a yr. Never balanced them and they work fine. I have had some flying buddies tell me that their Thunder Powers are not holding up and they won't use them anymore. But i have had no problems. The Eratix is an eye cather for sure. It fly's great and with the smaller asked for motor. You can use a 32 but not needed at all. It will just float in on landings. And does all the 3D you could want. There is a post in this forum on the Eratix and a Video of a guy MAVES that is awsume. I can't do what he does but it shows just how versatile the Eratix is. I can't believe they can keep them in stock. Easy building ARF but ends up around 5-7 hundred getting it airborne. I am on my third one (get over confiedent and try to close to the ground) and would for sure not have the third if it was just not a great plane. Now the wind will throw it around a little but that is cause it is so light. The Frenzy 100 is very similar in wing loading and the way it flys. Both are great flying planes.

tankertoad

OK so far I'm not too impressed with this RC Smart set up. First off, their ESC is only rated to 20 volts, which rules out using a 2x3s2p set up. They don't sell a 5s battery, so you have to go somewhere else...or buy thier 480kv motor and their newest 80A ESC which IS rated for 22.2v seperately. Next, the motor got here and it looked great, so I mounted it on a test stand (NO WAY I'm drilling my firewall just yet) and ran it up w/o a prop. I didn't even get as far as putting a meter on it before I noticed the prop shaft was wobbling. I figured it was bent, so I got an 8x1.25 mm auto stud from True Value and installed it. The stud wasn't bent, the threads in the motor were drilled off center. I can't see how this could happen on only 1 motor unless they are drilling them by hand (not likely) so I'm waiting for an e-mail to see what kind of a return I can get.