drkenb's Canon Portable Printers 
Portable printers are made for travel. As such, they do not require you to remove the printhead and/or ink cartridges before moving it. As a matter-of-fact, you should not remove the printhead and/or ink cartridges for any extended period of time, as this will result in ink drying out and clogging up the works. Always leave ink cartridges in the printer, even if they are empty, to prevent the ink jets and nozzles from drying out.
Always turn your printer OFF rather than simply unplugging it. Turning the printer OFF causes the printer to align the printhead so that it is sealed, preventing ink spills and drying out.
Reducing Ink Usage
I recently had a new i-80 owner write to me and complain that he was printing primarily text and was going through the black ink at a phenomenal rate – faster than he ever did with the BJC-85 he previously had. I pointed out to him that the i-Series has a much greater dot density (resolution) and that he might try setting the printer to print in “draft quality” mode and see how his text looked. We wrote back and thanked me for the suggestion, saying that the draft quality print for text on the i-80 was still much better than the regular print quality of the BJC-85… and he was using far less ink to print text than he had been with the i-80 set for its standard quality mode!
Moral of the story: you probably don’t need to print your text in photo-quality mode. Give the draft quality mode a try and see if that will yield the quality of text printing that you desire.
Power While Traveling
If you need to print where there often is no access to an AC outlet, such as in your automobile, on a plane or train, on a boat, etc., you have two options:
The slight advantage goes to the general all-purpose Power Inverter, since it will allow you to also power your cell phone and any other electrical gadget you may have with you, whereas the Canon DC Adapter is specific for your printer only. A Power Inverter is probably less expensive than a Canon DC Adapter, and easier to find.
Buying a Used Canon Portable Printer
As described on the Waste Ink page, every printer has a waste ink system that will eventually fill to capacity and need to be replaced. When the waste ink system fills to capacity, the printer will stop functioning until the waste ink system is replaced. Unfortunately, the waste ink system is not visible & so you don't know how full it is. You may hope that a printer which looks new on the outside is indicative of very little use, but that is not always true.
One way to maximize your purchasing power is to purchase a used system which has been refurbished, including the installation of a new waste ink system. Also make sure you select a used system which doesn't have any cracks or missing pieces of plastic from the case. Everyone wants a unit which looks good, but realize that portable printers are subject to the rigors of transport & as such, do get scuffed and scratched. Scuffs and surface scratches that do not denigrate the functional integrity of the unit are strictly cosmetic.
The Key Elements of a Good Used Printer
The key elements for selecting a good used printer are: (1) the remaining life of the waste ink absorber pads; (2) the case is physically intact with no broken or missing pieces; (3) the unit is functional; and (4) it comes with all components you need to use the printer right out of the box.
The remaining life of the waste ink pads is impossible to judge unless the printer is brand new (meaning it has NOT been used before) or the seller tells you explicitedly that they have been replaced with new pads. Other than that, its a crap-shoot. If the outside of the printer case is pristine, chances are it has been used very little and thus the waste ink pads are fairly virginal. In contrast, if the outside of the case is stuffed, scratched, has a ton of labels or label residue on it, or other signs of wear-&-tear, chances are the printer has seen significant prior use and the waste ink pads are nearing the end of their life. As the circus geek says, "You pays your money, you takes your chances!"
The quality of print is a function of the printhead, so if you find a used unit that meets all of the criteria above but the quality of print is poor, you can easily fix the print quality by a thorough cleaning of the printhead or, at worst, replacing the printhead with a brand new one for a retail cost of about $45.00.
The printer you purchase should, at a minimum, come with: