Please excuse my ignorance about this process. I have just read a number of posts about renewing non imm o visas, but am not sure they apply to my situation.

Last year in September I received my first non immigrant o visa (multi-entry) in Kuala Lumpur based on having a dependent child. That visa says enter before 13 September 2012. I've exited and re-entered Thailand every 90 days and I was ready to do it again to get the next 3 months which would take me into December, but I started reading about renewals of the non immig o visa here.

Do I need to apply for a renewal NOW before the visa expires on Sept 13, or, can I get the 3 month extension and apply for the visa renewal in December?

Do I need to return to Kuala Lumpur to renew it, or, can I just renew it at my local immigration office?

Or maybe I cannot renew it at all and I should just go back to Kuala Lumpur and apply through the process again?

Kuala Lumpur required 100,000 THB in a bank acct with my name - will it be 400,000 THB if I renew within Thailand??

Thanks for any help you can offer. Please be as specific as possible when answering or I'll be more lost than I am.

Cheers!

For now all you need to do is make another entry before September 13 for a new 90 day stay.

You can not "renew" a visa. You either extend your stay at immigration or you visit a Consulate to obtain a new visa.

If you extend it would be one year stay and 90 day address reports to immigration and require 400k in bank account at time of extension application (cost 1,900 baht).

Am surprised you were able to obtain multi entry visa in KL as normally only a single entry seems to be issued at local Consulates for child so you might want to contact them first if planning to do again. KL is known for issue with 100k for marriage but was not aware they would issue for child (which seems to be harder to obtain).