saw these not sure if there any good but might be worth a punt at under £20

http://www.eurocarparts.com/ecp/p/car-accessories/car-cleaning-accessories/cleaning/cleaning-accessories/?551770561&0&t5_499&utm_source=bm23&utm_medium=email&utm_term=Image+-+Streetwize+Portawasher/Portable+Power+8L+Sprayer&utm_content=End+Of+Month+Sale+%E2%80%93+30%25+Off+Online+%E2%80%93+Ends+Monday&utm_campaign=End+Of+Month+Sale+%E2%80%93+30%25+Off+Online+%E2%80%93+Ends+Monday&_bta_tid=300289699419456188690211828786799161655135355508457816856369675527107626343166960263478536

Also electric portable washers for £50

http://www.eurocarparts.com/ecp/p/car-accessories/car-cleaning-accessories/pressure-washers/domestic-pressure-washer-tools/?553773540&0&t5_570&utm_source=bm23&utm_medium=email&utm_term=Image+-+Streetwize+12v+Portable+Car+%26+Caravan+Presure+Washer&utm_content=End+Of+Month+Sale+%E2%80%93+30%25+Off+Online+%E2%80%93+Ends+Monday&utm_campaign=End+Of+Month+Sale+%E2%80%93+30%25+Off+Online+%E2%80%93+Ends+Monday&_bta_tid=300289699419456188690211828786799161655135355508457816856369675527107626343166960263478536

I’ve got similar to the top one and it works well.

I too have the top one , it’s a bit plasticky but is fine for bike and car washing . But I only paid £7.50 in a sale at Go Outdoors not £20 for mine.

Although it’s got a brush attachment it, otherwise it’s just a bog standard pressure sprayer, like this one which is almost half the price:
http://www.screwfix.com/p/green-pressure-sprayer-7ltr/51100#_=p

It is a good idea though – I put one in the car and use it to get the worst off after a ride, before it dries on. Also doesn’t ruin bearings like a proper pressure washer.

Got a hozelock similar to the top.one and it’s pretty good

Been using water bottles with “sports” cap or just a tiny hole made by a knife.

Ordered this one just now:
http://www.toollineuk.com/product.php?site=froogle&sn=82469

Wanted 10L so that I can waste some more on tires.

I’ve always wondered about this linked to a 25l water butt

http://www.ebay.co.uk/itm/12V-High-Pressure-Washer-Wash-Pump-80W-Kit-Marine-Deck-Car-Campervan-Sprayer-/282055939662?hash=item41abd8164e:g:yYAAAOSw9a5XPsxu

A mate has one similar to the 12v portable one. I use one similar to the other one. Both do a good job. The 12v one just does it quicker, which after a cold night ride can be a benefit.