HSRP version 1 & 2 differences

Some good difference:

1.HSRP v2 learns, advertises  millisecond times values which was missing in v1.

2. Vlan is increased from 255 to 4095 which allows to makes more groups.

3. HSRP v2 allows to know which router sent the message because earlier the source message had VMAC 0c07 virtual address.Version 2 includes a 6 byte identifier field that is used to identify the message sending node.

4 HSRP v1 uses multicast address 224.0.0.2(also used by CGMP) to communicate with its peers over the same subnet in a group  & for to exchange hello packets. Now v2 uses 224.0.0.102 in v2. 

5. Uses a new MAC address range 0000.0C9F.F000 to 0000.0C9F.FFFF.

6. HSRP version 2 has a different packet format than HSRP version 1. The packet format uses a type-length-value (TLV) format. HSRP version 2 packets received by an HSRP version 1 router will have the type field mapped to the version field by HSRP version 1 and subsequently ignored.

All you need to do is add one more interface sub-command:

R1(config-if)# standby version 2

But make sure you remember HSRP v2 and v1 are not compatible. So v2 can't make in a group with v1 for gateway load balancing.

Cheers!!