Has anyone tried one of these multiple charging boards? http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 193979691I see a number of international sellers on ebay. Safe to use or will this fark my batteries? I've seen other multi charger that say the all the batteries should have a similar battery level when charging them together. Would that apply to this too? If using this is a bad idea, are there any recommendations for other means of charging multiple batteries?