Battery options and questions about them

[jlaudio_revo]

I am wanting to buy a brushless electric RC plane (I know this isn't the plane forum but this one has more traffic and this is just a battery discussion anyway). It has (800kv) and 25A Brushless ESC. < I got that from the site I plan to buy my plane from. I know it has a 11.1v 1800mah Li-Po battery in it when you buy it but I am afraid to run a Li-Po battery because of all the bad things I have heard about them (exploding and involved maintenance). I was wondering if I could run a Ni-MH battery in this plane or not. If so what volt and what mah should I use? I am trying to get the most flight time I possibly can out of my plane. I'm not really looking for more power. If I can ONLY run a Li-Po battery then what would be the best one for longer flight time?

 

[alpinehyperlite]

Lipo is recomened for its light weights, and high discharge/mah in a small package. Dont become "afraid" of lipo. As long as you take the proper procautions, everything will be fine with them.

 

[jlaudio_revo]

Bump to the top for more information

 

[hndaman1]

do not be afraid of lipos..they are awesome,and this place has the best deals on them..People say that the "cheap lipos are bad, but I have ran the turnigy batteries and they are great..

http://www.hobbycity.com/hobbycity/store/uh_index.asp
http://www.hobbyking.com/hobbyking/store/uh_index.asp

 

[jlaudio_revo]

I gotta ask, what is wrong with the 10000mah Li-Po battery sold on eBay? I was told to stay away from eBay batteries. I was only looking at it for the 10000mah. Like I said before I am trying to get the "MOST" flight time I possibly can out of my plane.

The other worry I have is I was told when you get below a certain point on a Li-Po battery something will cut the power as to not damage the battery. That can be a huge disaster in a plane when you're in the sky.

Another question I have is what is the best charger for Li-Po batteries that wont cost me a fortune?

 

[alpinehyperlite]

a 10,000 mah lipo, will probably weigh like 2 lbs.

 

[jlaudio_revo]

Here is the one I found

http://cgi.ebay.com/RCS-10000mah-11-1v-10C-LiPo-Li-Polymer-Li-Battery-RB520-/250661934158?pt=AU_Toys_Hobbies_Radio_Controlled_Vehicles&hash=item3a5c9d944e

 

[alpinehyperlite]

That thing is going to be qaartardedly heavy. WAY too heavy for a small plane.

 

[jlaudio_revo]

It says 761 grams but I'm not sure exactly how much that is. I know a nickle is 5 grams.

Here is the information I got from the website


Specifications

Wingspan: 55.5in/1410mm
Overall Length:40.5in/1030mm
Flying Weight: 1100g
Wing Area: 27.35dm²
Wing Loading: 34g/dm²
Drive System: Brushless Outrunner Motor (800kv)
Servo: 4X 9g High Speed Micro Servos
Speed Controller: 25A Brushless ESC
Battery: 11.1V 1800mAh Li-Poly
Control System: 2.4Ghz 4 CH Multi-functional FHSS Radio Transmitter and 6 CH Micro Receiver
Radio Control Range: 3000 Feet (1000m)

I just want more than 15 minutes out of it. That's not very much flight time and they say you will get 15 minutes at BEST. I want more time than that.

 

[alpinehyperlite]

That is 1.67 lbs, and the references to a "nickle" isnt really welcomed here.

 

[jlaudio_revo]

What do you mean? A nickle does weigh 5 grams. That's why its a nickle. If it weighed 6 grams it would be worth 6 cents. 7 grams / 7 cents and so on.

That aside what do you suggest for a battery?

 

[alpinehyperlite]

Which plane did you get? If it comes stock with an 1800mah 3s lipo, i'd just use that.

 

[jlaudio_revo]

http://www.nitroplanes.com/93a182-skytrainer-rtf-24g-v3-blue.html

I was going to buy one next week but I want a little more flight time. 10 minutes isn't a good amount of flight time to me.

 

[hamz9561]

You are usually limited to a certain physical size. You can run a higher capacity pack if it will fit in the space. I run a slightly larger than stock pack in my micro helis and I get about 8-10 minutes of flight time on 800 mAH capacity.

 

[jlaudio_revo]

OK well I would like to get 20 minutes if at all possible.

The site says it will run for 20 minutes (I just saw this) thought it said 15. I know that it will usually only run for about 12 minutes at WOT. My friend has this plane in red and he gets between 11 and 13 minutes out of his. We are both wanting to know what we should use to get 20 or even 25 minutes out of it.

 

[alpinehyperlite]

You might be able to go up to like a 2200mah, but it would probably be best to get just a couple stockers, land, change the battery, and fly again.

 

[frickenjoey]

Sorry I have not chimed in earlier but these guys are correct about the batteries. I have a .40-.60 sized brushless trainer. It has a 62" wing span. It has a 90 amp ESC which I run at 4s. I run 2 2s 8000mah Max Amps batteries together making 4s or 4 4000mah 2s batteries with two pair of them in parallel giving me basically the same thing (4s). Your biggest concern will be space and weight. The total flight weight of you plane is 1100g...that is with the battery included. So not only would that big 10,000Mah battery not fit it would weigh damn near as much as the plane....it just might not get off the ground! But not to worry there are tons of options out there. I just pulled this off of the Hobby King web site and this is the appox size and weight you are looking at for batteries for your plane.
Spec.
Minimum Capacity: 1800mAh
Configuration: 3S1P / 11.1v / 3Cell
Constant Discharge: 20C
Peak Discharge (10sec): 30C
Pack Weight: 153g
Pack Size: 110 x 34 x 21mm
I found this one, I can't promise it would fit but that is just about the biggest you would be able to get in to there it is a 3000mah 3s. Think about it....if an 1800mah will give you 20 minutes the 3000mah should get you into the range of about 30 minutes.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9952

Most aircraft esc have a soft cut-off for the batteries....when you hit voltage cut-off the power will cut in half. So when you notice the power is just all of a sudden gone....time to bring it in (you will still have full servo control). I went one step further even, I got cheap lipo alarms and rigged up LEDs to the bottom of the plane so if I thought I just hit the cut-off I could bring it in for a pass and see the light flashing. Also....you can time it pretty well too. What I did was with the plane on the ground I timed how long at full throttle it would take to run the batteries down and set a timer for a minute or two less to be safe...when the timer went off... I knew I needed to bring it in pretty soon. You do this and you will always be safe. I never ruined a pack this way.

 

[jlaudio_revo]

Thanks joey! That is some GREAT info! I would be very happy if I could get 30 minutes out of it. I just noticed you can get a second battery from the site when you are ordering the plane (drop down box). I can get a 2200mah battery for $11.00 extra when I buy the plane. I will start there I guess and if I feel like I need more time I will buy the 3000mah you suggested.

That is great about the soft cut-off. I was worried it would just cut all the power and I would be a dead stick in the air. If that were the case I would not want to go with a Li-Po just for that reason.

 

[frickenjoey]

I have never seen a aircraft esc with a hard cut off....yeah that would be bad. My plane has a separate receiver battery so even it it was a hard cut I would still be fine. I would check HobbyKing if I was you. I have gotten a lot of batteries from them and have been pretty happy with them so far. Great prices too. I really have to say a 30 min flight time and you neck is going to get sore....lol.