There are a couple of battery powered DA machines that whilst no good for any kind of paint correction work, due to not having enough power, they would suffice for the application of products such as PB's in this case.

The first one was made by Meguiar's but it's been out of production for a few years now and so other than getting lucky on ebay, you might struggle to find one.

The other (which is usally for sale on ebay all the time) is a yellow coloured machine from SIP and is a dual action cordless unit that normally goes for about £40-50 ish. I think it only comes with one battery though and I've not used it myself so can't vouch for how effective it is at applying waxes and sealants etc.

Found one:-

http://cgi.ebay.co.uk/Cosmo-Cordless...d=p3286.c0.m14