ORIGINAL: PrkFlyrRic
I was just in Wal-mart and saw these; [link=http://www.walmart.com/catalog/product.do?product_id=4291462]Wal-Mart rechargeable AAA's[/link]
They are a bit high priced but figure you only need three packs to make two packs for the AF1 and NO shipping.
I bet other places, (radio Shack or K-Mart), has them cheaper, maybe even different mAh ratings.
With connectors from a hobby shop they should come in around $17-$18 a pack.
As for soldering your own packs do a search on the forums or check the web.
I did my own back when I raced electric cars and it's not hard to do.
The biggest thing is to "tin" the link first and don't heat up the battery.
Ric
Dude, those batteries WILL NOT WORK IN the 747 or any RC plane for that matter.
NOT ALL RECHARGEABLE NiMH/NiCD batteries are the same. BIG differences.
Those you buy at Walmart are called "consumer grade" rechargables that are only good for small current discharge. They power your digicam, electric shaver, ...etc just fine and you can use them as reciever battery or in some cheap transmitters. However they will NOT provide the high current draw needed to power a RC grade motor for flying.
If you want to build your own packs you need to buy RC grade high discharge cells from say cheapbatteries.com. Notice that they also sells many different grade of cells you have to read carefully about their discription. The stock pack for the 747 is a 8cell 650mAh 2/3 AAA pack. Cheapbatterypacks.com sells similar sized cells with higher power and capacity.
You also need to consider weight you cannot just use large NiMH packs. If you want more during you should consider using 2 cell or 3 cell LiPo battery.