Do yourself a favor, and don't buy the Coghlan's 0817 Battery Powered Air Pump. I picked one up because I wanted to save myself the hassle of pumping up our inflatable raft by hand. I had pretty low expectations for the $12.00 pump, but it still didn't meet them.
When the pump arrived I put in fresh batteries and hit on the switch. Nothing. I flipped the batteries over. Nothing. I put in another new set of batteries. Nothing. I flipped those. Nothing. Ugh. I had a dud. Off to Amazon I went, where I requested a return. The Amazon experience was hassle free; they'd send me a new one and pay to ship back the broken one.
The second pump arrives. I put in fresh batteries. And...nothing. What are the odds of getting two dead pumps?!
Normally I would have trudged over the computer and requested a refund and bought a new brand. But for the heck of it, I thought I'd troubleshoot the situation. I didn't really have a plan, but I un-bent a paper clip and touched the battery ends like so:
To my surprise, the pump whirred to life. Interesting. So the problem wasn't actually the motor in the pump. I then fiddled some more. Again, pretty much randomly, I grabbed a bit of aluminum foil from the kitchen and wadded it up. I then put it on one of the ends of the batteries. My thinking was that maybe the plastic that held the battery in place was just a little too long, not allowing it to make contact with the battery. Basically, I did this:
To my absolute shock and amazement, the pump fully came alive when I hit on the on switch. So yeah, if you do buy this pump and it doesn't work, you may want to try a little foil to help the batteries make contact.
I suppose I can't really complain: not only did I get a pump out of the deal, but I got a little boost of electronics-troubleshoot confidence, which is rare for me. Hurray for aluminum foil and paperclips!