What just happened to my cheap batteries from China?
As I posted in another thread I got these cheap "Powercell" batteries from China and used them with great success in kitchen drink mixers, pepper grinders, etc. Last week I decided it would be worth using them in my grayscale handheld PC from 1999 (still very useful and the grayscale screen means I can view it in direct sunlight, in fact that's when the screen is clearest, it allows me to do lots of my work outside during the summer). I had been using my Duraloops in it and they lasted 2-3 weeks of daily use before getting at 30% when Windows starts complaining about low power.
The Powercells worked great for the first few days and today I took it and in control panel I think it said the batteries where at 70%, so I quickly update an excel workbook and save it. Then for some reason I open the battery door and just move them around and close it. I turn it back on and Windows immediately says "Main batteries are very low", I figured I placed them wrong and move them again, now the computer can't even power on for more than a flash on the screen. I move them again a few times, nothing, put duraloops I had in storage, turns on and says 90% charge, put the Powercells, still just a flash before it dies.
What I don't understand is why where they working great and powering the handheld with the back light (the back light uses about 5-10 times more power the the entire rest of the computer) and saying 70% charge, and then just from moving the batteries they are now deader than dead?
Anyway, I'll be using only Duraloops from now on, these handhelds run entirely from ram, they are like a laptop with no hard drive, and a partition of ram is reserved as your storage "drive" (which you can resize in realtime at any time). If you know how ram works, you know this means if the device runs out of power, your c:\ drive gets wiped clean. That's why they all have an emergency backup watch battery that can power the RAM (but not power the entire device) for several days or even weeks even with the main batteries removed. Even though it has a backup battery, I want to keep reliable Duraloops on this thing considering it cannot run out of power at any time, though I have a backup it's not always too recent.
This is the handhelc PC I'm using in case you're wondering, they're awesome devices even for today for work like word, excel, email, and there's 2 expansion slots so you can add wifi and a flash card or whatever hardware you want (it uses PCMCIA cards and Compact Flash cards). It's only 54mhz but that's plenty for a device like this, it runs very fast and even programs like excel start in about a second, and a full system reboot takes an amazing 6 seconds (
video of reboot).