Little update, I've actually cancelled my order of Graphene 4s 6000mah from hobbyking and instead (after looking about) for a bit more money you can get a much better spec battery from Ludicrous Lipo's. Nice that it's a UK company as well, reviews on them seem very positive so I'm gonna take a punt on these as they seem to be the best out there without importing from the US. They come with a 6 month warranty for piece of mind.
LUDICROUS Lipo's 8000mAh 4s 14.8v Race Spec Lipo:
LUDICROUS LI-PO's offer an excellent value by providing factory direct pricing and quality that meets or exceeds that of other major battery manufacturers. Our batteries go through strict testing and quality control procedures in order to provide extremely accurate mAh, Voltage, and C ratings.
Don't let their low cost fool you, these batteries outperform major manufacturers batteries!!
Features:
True Capacity and C-Rating
4mm Bullet Output Leads for Continuous High Current Draw
Thick 12AWG Discharge Leads
Durable Hard Case
Deans Ultra Connector
JST-XH Balance connector
4mm Bullet Leads
Capacity: 8000mAh
Voltage: 4S /Â 4 Cell / 14.8v
Discharge Rate: 100C Constant (800A) / 200C Burst (10 sec) (1600A)
Charge Rate: 2C (16.0A) Max, 1C (8.0A) Recommended
Watt Hours: 59.20 Wh
Weight: 600G
Dimensions LxWxH: 138 x 46.5 x 45.0 mm
Discharge Plug: Deans Ultra Connector
Balance Plug: JST-XH