Hello Howard.
Hobby King USA has Zippy Flite Max 700 mAh, 6.6V, 5c LiFePo4 receiver packs in stock, sku#Z7002S-5F. Weight is 55 grams, and they are in stock. Price is $2.78 each. They have them in the US warehouse, which is located in Parkland, WA. You can go pick them up.
Tom