I didn't get it.Javascript on login is for reCaptcha.I tried to solve a reCaptcha in Tor Browser ( which doesn't let you use JavaScript on default plugin settings ) and it gave me a code to copy-paste for solving the captcha.Since now the login page says it requires Java it's probably true.Solving a single captcha doesn't going to drain your battery or it won't do something while you are surfing the forum.