Hello,
I got one of those u-blox GPS modules from ebay for really cheap, like $15. It takes quite a while for it to get a GPS lock from a powered off situation - about 8 minutes. There seems to be a tiny tiny battery that maybe is suppose to save the previous gps data to help it lock on faster? Well, maybe the battery is too small to be of any help.
Has anyone had good experiences with a cheap (less than $30) GPS module? Looking for getting GPS lock within say 2 minutes. Do any of them come with built-in memory so it doesn't have to relay on a little coin battery?
Eight minutes to a satellite lock (it can take up to 15 minutes) is fairly typical of a "manufacturer cold start", meaning that the module has to receive and process all of the information on satellite orbits. I suspect that the cheap Chinese module that you bought has a dead battery or a defective battery backup circuit.
Just about any of the recently manufactured battery-backed modules are normally quite fast, especially if they have recently seen some satellites. My UBlox LEA-6H can get a lock in less that 15 seconds if it has been on, and had a satellite lock at any time in the last month or so. I bought it from 3D Robotics but they no longer sell that particular module.