http://www.nikonchat.com/nikon-d70-battery/
What would be a good flash to buy a Nikon D70 .. something that does not drain the batteries faster?
If you want TTL flash metering, which has 3 options. The Nikon SB-400, 600 and 800. There are also numerous third-party manufacturers that make the flash heads are compatible with Nikon cameras, but I've never used one so I can not give information on both how they work. If you want a flash head can, go with the SB-400. They run about $ 100 and use of AA batteries. Drainage batteries depends on the type you use and the power output. If bright conditions and you are in need of full powers to fill the balance, the battery is shorter. Standard alkaline AA usually does not last long, NiMH rechargeable AA are the best in my experience. Duracell makes a package for 4 with a charger at $ 17 any grocery store.
Unboxing Nikon SB600
Nikon News