I’ve never used a helmet light before & i’ve got one of those 1200lm ebay jobbies with a separate battery pack which i intend to use strapped to me noggin.
I’m not a fan of camelbaks so would prefer not to use one, but does having the battery strapped to your helmet casue it wobble about more?

depends on the weight of the battery.

I have the light at the front (not on top – it hits too many branches up there) and battery at the back and as I have a relatively small battery it balances out. It feels heavier than normal to start with bu after 10 minutes you don’t notice.

You can always run the cable and battery down to a jersey pocket? Makes taking the hat off more awkward but not much.

I’ve got a 2 cell battery for my helmet light which I’ve fitted to the back of the helmet to balance the weight. As wwaswas says, you don’t notice it after a while. Don’t think I’d want a 4 (or more) cell battery on my noggin’ tbh

I have a similar light to you, just having the light on the helmet feels heavy but something I have got used to, the battery pack on the helmet would be awful! Well for me at least! You might have a titanium neck! My battery lives in my camelbak, I always use one so it’s not a problem.

Edit:

You can always run the cable and battery down to a jersey pocket? Makes taking the hat off more awkward but not much.

This is a better option in my opinion. Too much weight on your helmet does not feel nice.

mos, I suspect I’ve got a similar light. Light mounted on the top of my helmet, battery pack on the back.
Initially I notice it when I put the helmet on but within a few minutes no problem. Only way to find out is give it a go.
Big advantage is that the cables are kept out of the way.

http://www.ebay.co.uk/itm/CREE-Q5-LED-Flashlight-7W-300LM-Torch-Adjustable-Focus-Zoom-Light-Waterproof-UK-/251313762786?pt=UK_SportsLeisure_Camping_LightsLanternsTorches&hash=item3a8377b1e2

I’ve two of these things cable tied to either side of my helmet. Awesome dude! Well not bad for the money and surprisingly light. Doesn’t throw the light too far but floods a 5m spread wherever you are looking.

You can always run the cable and battery down to a jersey pocket.

This.

I have the four cell battery on the back of my helmet as low as possible.

I quickly got use to the weight.