"After all our hard work, five minutes into the second half we were two-all, so that part of it wasn't good enough and we need to improve in that area."
In sweltering temperatures approaching 35 degrees, Batch discounted fatigue as an issue in the second half slump.
"It was purely mental. We weren't prepared for the second half, gave the ball away too much and let them run at us. I think you see as players get tired the game opens up in very hot conditions, but it's still no excuse for our second half performance."
The Black Sticks had earlier taken the lead in the seventh minute of the game after claiming back-to-back penalty corners. Veteran striker Phil Burrows showed his class, regathering a deflection twice before crashing the ball into the goal on his reverse stick.
New Zealand's buffer increased late in the first half with Simon Child catching the German defence napping from a free hit, sending a pin-point reverse tomahawk cross into the circle for Nick Wilson to deflect past the goalkeeper.
The Germans created several chances of their own in the first half but were kept out thanks to some well-organised Kiwi defence, led by 24-year-old Hamish McGregor in goal.
After the break, though, it all changed, with Germany coming out firing and striking back with two goals in the space of two minutes.
Marco Miltkau was first to fire for the Olympic gold medallists, sweeping his way around the legs of McGregor before Mats Grambusch levelled the score at 2-2.
The score changed hands several times as time ticked away, with Stephen Jenness and Nick Haig adding to New Zealand's total. But a further four German goals sealed the result as Jan Christopher Ruehr scored two of the tournament's best goals late in the half.
The Black Sticks play England at 10:30am tomorrow in their last game of the tournament.
