Diode selection

<SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Verdana">I recently purchased a AX3500 and I would like to properly hook everything up. <SPAN style="mso-spacerun: yes"> </SPAN>My project is using two 11.6A 24V Merits motors and two 18A 12V batteries in series. </SPAN><BR><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Verdana"></SPAN> <BR><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Verdana">I would like to know how to calculate the <FONT color=#ff0000><B>diode </B></FONT>used across the battery(s)? <SPAN style="mso-spacerun: yes"> </SPAN><SPAN style="mso-spacerun: yes"> </SPAN></SPAN><BR>

The diode is not really necessary in your case. At 24V and the relatively low amperage of your motors, regeneration damage is very unlikely.

Just make sure that you use the Power Control wire to turn on/off, while you maintain a permanent connection to the battery (via a fuse, preferably) to the VMot tabs.