Adjusting Customer Session Length

I am using Zen Cart 1.5.3 and am having issues extending my customer session length. I have tried a few things including adding php_value session.gc_maxlifetime 86400 to my root .htaccess. I have also tried editing the $SESS_LIFE = 1440; variable in sessions.php. My session.gc_maxlifetime local and master stay set at 900 and 1400 respectively no matter what I try. I am not sure if those numbers should change but regardless, my session times out after the 15 min my local is set to. I have recently tried installing keepcart and although it appears to have installed successfully, my session still times out. I am thinking it must be something related to the server setup but do not know where to go from here. Any advice would be appreciated.

Also, just to clarify this is occurring during guest checkout and I do have COWOA installed.

Why exactly are you finding the need to extend customer dormant session length? How long are you wanting to set it to?

DrByte:

Why exactly are you finding the need to extend customer dormant session length? How long are you wanting to set it to?

I seem to be losing quite a few mobile customers as a result of the session expiring. It seems as though they become busy doing something else and then come back and are not able to place the order. Some of them re-shop but most just leave. I do not want to extend it to the 24 hours I have in the .htaccess. I just threw that in there to test it. I would like to set it to a half hour or an hour. Thank you for the help.