I have been using a slightly more expensive battery solution for the Bushmaster, but I have refrained from making that known because of the less than convenient effort that is required to get hold of one.
Worse still is that I lent my BM out and packed away the battery. Now I can't remember where I put it .
But I am going to do a wide search tomorrow. I hope the wife didn't throw the box away in which I left it.

The battery can be seen at:
http://www.ebay.co.uk/itm/3309191249...84.m1423.l2649

I ordered mine from:
http://www.ankaka.com/incredible-200...tery_p409.html since it is a bit cheaper there even after adding the postal cost.

Some more technical info on it at:
http://sclick.net/cool-gadgets/coole...gets-blog.html

What I like about it is that you can leave it plugged into the mains. It has a battery level indicator, and an auto shutdown when fully charged.

The unit defaults to 12Volts. This is important. The BM draws less than 100mA, which makes it unsuitable or difficult to use with other battery solutions of a similar design that I have tried. That includes the one at:
http://www.ebay.co.uk/itm/UBP0768A-2...item35c9c2399c
This one has a 16V minimum limit and does not detect the presence of the BM consistently. So it won't come on reliably. I shall take a pic of it the next time I do get it to recognize the BM just to show how it works.