I "believe" the battery is the same (connector, voltage, etc.), but you likely will have a battery included when you purchase the H700 kit. Shouldn't be much else you need to do.
I have a PE T410 with a PERC 6i PCI card, and I'm using 2TB SAS drives.  I'd like to replace the drives with 4TB SAS, and it looks like I need the H700 to do this.  Aside from the H700 and new cables, is there anything else I need to do this conversion?  Battery still the same?  Thanks. 
PERC 6i to H700