Hello all. Well today I bought my first plane. Nothing much (but I'm still excited!!!), just something to fly while I decide what kit to buy because I want to build a plane. I bought a Hobby Zone Aero Bird Swift. It came with a 7 cell 8.4V 1000mAh NiMH and the box said it could be upgraded to an 8 cell 9.6V 1000mAh NiMH. All though I know this hobby is not a cheap one I am trying to stay as frugal as possible. I have three options that I see. First, pony up the $25-$30 NiMH from Hobby Zone. Second, buy individual NiMH's and solder them together to make my own pack. This looks to me to be about the most cost effective route as I have found 1.2V 2300mAh AA size batteries for under $1 each and I already have everything else I would need to make a battery pack (I work with marine electronics by trade and have access to all the material I would need to make to make the pack). Or lastly, go with LiPo. From what I understand, if I increase my mAh I will simply be lengthening my flight time and an increase in voltage will increase my power. I would prefer to go with LiPo but it would appear they only come in 7.4V (less than the battery in the box) and 11.1V (above the upgrade battery). So... what should I do??? Any suggestions would be greatly appreciated.

Thanks in advance

Brett

As you suspect LiPo would be your best alternative, though it's not without its drawbacks. Quite apart from its tendencies to explode & burn your house down at odd moments LiPo requires special chargers that can provide a balanced charge (which aren't cheap). You're probably not going to need (or even want) higher voltage than the 9.6V - chances are the ESC is only rated that high. Higher mAh is what you're after for longer flight times, though be careful of adding extra weight (again why LiPo's are better, they're much lighter and have much higher current capabilities).

If you're not prepared to shell out for the LiPo charger, I'd look at building my own packs. Make sure you get the cells with the solder tags already in place as soldering directly to a cell will heat up up so much you'll probably damage it. First thing I'd do though (before shelling out any cash) is learn to fly your plane and see what the standard battery's capable of. There's no point in spending big bucks till you know you're not going to kill the plane, lose interest, etc.

Well, Brett, increasing the voltage could do harm to the ESC and the motor. You should pretty much stick with what the min-max voltage requirements that the manual says.

Now, as far as capacity, that's a different story. The only real limitation there is the physical size and the weight of the pack. Of course, if you exceed the weight that the plane can carry in order to gain sufficient lift to fly, well, it just won't fly.

There are some that will construct their own battery packs out of individual cells. There is a problem with that because of the heat required to obtain a proper bonding when soldering the packs in series (or in parallel for that matter). It has to be done fast enough so that the interior of the battery is not damaged. Most people don't have that knowledge or ability. Being frugal is a good thing, however, battery packs are not all that expensive. For the Aero Bird Swift, it is not all that powerful and increasing the weight by an ounce or two may cause problems with flying it.

If I may suggest an alternative, go to Tower Hobbies, or RadicalRC.com and pick up a spare battery pack or two of the capacity that Hobby Zone supplies. Then keep those charged. If you are going to stick with this hobby, spare battery packs are always useful. And, a decent field charger is also something that you will always find useful.

But, if you are dead set in making your own packs, and feel comfortable with making them yourself, then give it a shot. Just be aware of what I've said about putting them together. And, internal failure of a battery cell is it's kiss of death. And, heat is not a friend to batteries, so whatever you do, do it quickly, don't linger with the hot soldering iron.

Good luck.

CGr.

9.6v is what most transmitters run at, so you can probably find a pack made for transmitters in the BST forums here or on Ebay. Do understand that you get what you pay for though. Not all cells are equal, and the good ones will cost $2-$3 each. Cheap ones don't last as long, don't put out as much current, aren't as tolerant of abuse (and flying is abusive) and don't hold charge as well. The best NimH cells on the market are Sanyo Eneloops. All Sanyos are good, and most guys flying more expensive planes won't use anything else, myself included.
Since you're asking for advice, I'll offer than cheap batteries offer no cost savings whatsoever. You'll replace them sooner than good batteries, and they will occasionally cost you an airplane.

Thank you all for your help. The more I learn about this hobby the more I realize I have left to learn. Thank God for this forum and all of you willing to offer up your advice.

Brett

It does get simpler once you get over the initial hump. It gets alot more fun too. RC'ers are, IMO, the most helpful and generous hobbyists that I have ever been around. You're going to enjoy it.