Topeak Moonshine Commuter lights

I have recently purchased these lights they have a dual setting 6 & 10 watt,
with a 1/2 hr reserve tank.

I previously had an old set of Cateye Daylights with a single 6 watt
headlight.

The new lights on the 6 watt setting are virtually useless, the 10 watt is
only just acceptable.They have a NimH battery

I have used these approx 4 times and recharged fully each time, last night I
had the 10 watt on for only 1 hr before it went into the 6 watt reserve
mode, luckily I was only 1 km from home, I live in a rural area in Australia
and we need good lights to spot the kangaroo's (seriously they are big
problem here they just run out in front of you, cars hit them all the time).

Anyone have experience with these lights