ORIGINAL: 2slow2matter
i think that a battery tester (ESV) is a must. Otherwise, you are just rolling the dice on every flight....
Yeah,something to test you batteries is a MUST. I used a standard old radioshack voltmeter for awhile before getting a meter made for this task. Regular radioshack type voltmeters dont test your battery under a "load" like the good meters do,so they arent totally accurate like a good meter. But for me it was better then nothing and can give you an idea of what your batteries are up to.
Heres a nice cheap one like I bought and works just fine...
http://www3.towerhobbies.com/cgi-bin...&I=LXWW16&P=ML