Basic Battery Questions
 

So I'm looking into getting an electric trainer for my first plane - Hobbico SuperStar EP Select RTF w/Ailerons 50.

This plane uses 8.4v 2100-3600mah flat batteries (going to buy 1 or 2 extra so I have 2 or 3 total)

-Does more mah mean longer flight time?
-Can you interchange Nimh, Nicad, and Lipo? (which is better, Nimh or Nicad)?
-Is there any way to obtain 10-15min flight times with an electric trainer?
-Does it really take an hour to charge a battery when the advertisement says 15min?

Thanks.

RE: Basic Battery Questions
 

Yes, the mAh rating is the battery capacity or "fuel tank" size.


I'm not exactly an expert on electrics but I imagine that would depend on the ESC. I know some work with various types of batteries and some don't. maybe someone else can elaborate on that. As far as which is better, that depends on application. Nicads can provide a lot of power quickly and are very cost effective but require regular cycling while NiMh has higher capacity than NiCad given the same physical size but some may not be able to deliver it as quickly. Everything has good and bad qualities and everything has areas where it works well.


I don't see why not if you have a fairly high capacity battery and manage the throttle.


Again, I'm no expert but I'd be careful about charging batteries too fast. To do it means more current being pushed into the battery, resulting in more heat. From what I understand, 1C is the fastest you want to charge most batteries. (1C=1xrated capacity. For a 1000mAh battery, 1C would equal 1000ma or 1A). This should theoretically give a charge time in the 1 hour range. I could be wrong about this however, maybe someone else can elaborate.

Check our http://www.batteryuniversity.com

It's a very informative site.

RE: Basic Battery Questions
 

you need lipos you will have to make sure your esc and motor can take the change or they will go up in smoke.

RE: Basic Battery Questions
 

To get 10-15 minutes flying time with an electric, you pretty much need to get a brushless motor/ESC and LiPo battery pack setup. The SuperStar EP Select comes with a brushed motor/ESC and a NiCd pack, so your probably going to get about 5-10 minutes of flight time. Getting higher capacity NiCd or NiMH batteries might extend that, but then you'll be adding weight, and it won't fly as well. From what I've heard, the stock motor/ESC/batt barely flies it, so adding more weight may not be a great idea.

The ESC that comes with it probably doesn't have the proper voltage cutoff for LiPo packs.

If I were you, I'd get an ElectriStar. It comes with a brushless motor/ESC and a radio system. You can buy some NiCd or NiMH battery packs for it to save some $$ initially, and I'm told it flies fine as a trainer with that setup. Later on you can upgrade to LiPo batteries, save about a pound in weight, and it will fly longer and be more sporty/aerobatic.

http://www3.towerhobbies.com/cgi-bin...=LXNVC0**&P=ML

RE: Basic Battery Questions
 

can someone show me a dygram to use a 4 cell lipo on a electristar [email protected]

RE: Basic Battery Questions
 

John, you actually match the battery to the ESC and both to the motor you are going to use. The airplane means almost nothing other than deciding what size motor to start with. And the number of cells doesn't have any importance to the diagram.

Most ESCs come with a diagram, and most motors come with instructions for their proper wiring.

RE: Basic Battery Questions
 

Basically, if the battery came with a connector on it, you plug that into the ESC's battery connection if it fits. Check the polarity first, obviously. For single battery setups, that holds true for 1, 2, 3, and 4 cell LiPos. If the battery did not come with a plug, you need to buy one that matches your ESC plug, if it came with a plug that is. A great number of ESCs and batteries don't have plugs attached. The reason is that there are a number of popular choices. And it's cheaper.

RE: Basic Battery Questions
 

I think he's asking because the Electristar has two Deans connectors meant to hook up two 2-cell LiPo packs in series. Sounds like he wants to use a single 4-cell LiPo. If this is the case, then he'd have to buy another Deans connector and solder a short across it, to short out one of the two connectors in the plane, and then connect his 4-cell Lipo pack to the remaining connector. Just make sure that the 4-cell LiPo can source enough current for the Electristar. The recommended 2-cell LiPos put can put out 64A continuous, so shoot for that.

RE: Basic Battery Questions
 

I'm going to disagree with a few others here:
#1 More mAh does mean longer flight time. The more mAh (bigger battery) generally (but not always) means a heavier and larger physical battery.
#2 NiMh and NiCAD batteries can be interchanged in this and most instances. The supplied NiCAD batteries will be fine. It's true you will have to periodically cycle a NiCAD, but there's tons of information on the subject, and it's really not a big deal. I try to cycle once a month.
#3 The Superstar should have no problem getting 10min flight times, up to 15 minutes if you just cruise around. I have a buddy with one. I was impressed. It's not an overly fantastic plane, but it's capeable and nice, easy to repair and very simple.
#4 The charge time depends on the charger you use. A battery of this capacity can be charged in 15min, but in the interest of battery life, I wouldn't. Besides, if you get an extra battery and keep one on the charger, you'll need the downtime to let your nerves recover, especially if you're a bigginer. It'd also be nice if the motor/battery/ESC cooled between flights. A one hour charge time would be more reasonable. Charge the packs overnight (slow) before you go flying the next day.

Likely a LiPo cannot be used with the ESC (electronic speed control) supplied with the kit, because (as already stated) the voltage cutoff probably won't match..... unless it's a programmable ESC. LiPo's of this capacity are VERY expensive anyways. The only real advantage is weight. The plane was designed for the big NiCAD so I wouldn't worry about it.

IMHO

RE: Basic Battery Questions
 

do i plug male connector and end it or do i plug male connector soider end together that what i think ment by short it

RE: Basic Battery Questions
 

Your ESC should have two male deans connectors like the ones in the first photo below. The second photo shows a male Deans connector on the left, and a female Deans connector on the right. You need a female Deans connector with the solder tabs shorted together. You plug the shorted female connector onto one of the male ESC connectors, and you plug your battery pack onto the other ESC connector.

Alternatively, you could just short out one of the male Deans conectors on the ESC, but then you wouldn't be able to go back to running two packs in series again without undoing the modification.

RE: Basic Battery Questions
 

thanks that helped alot