Use the above £5 off voucher and SIM card trick to get these prices.
8 x Energizer Ultimate C 2 Pack Batteries Packs (16 Batteries) for £10.15
8 x Energizer Ultimate D 2 Pack Batteries Packs (16 Batteries) for £10.15
8 x Energizer Ultimate AA 4 Pack Batteries (32 Batteries) for £9.35
4 x Panasonic Essential Power Alkaline AAA 24 Pack Batteries (96 Batteries) for £11.01
You can mix and match with them just remember to get the subtotal over £25 including the SIM card to be able use use the £5 off voucher.
Dont forget Quidco.