You can't update a psp without a working battery. It'll state that the battery is low and you need to charge it.
Yes you can, the PSP battery will continue to charge even when you are playing. I would not recommend to do that, it is better if you leave it to charge and then play.
It's only possible to turn on your PSP with an adapter for the PSP or a battery for the PSP.
You might need a new charger or battery.
You can run a PSP without it having a battery, it's not very convenient though. It will only operate while it has the charger in.
It takes about 2 - 3 hours for a full charge
I suggest you get a new battery...
You need to have a psp1 or a psp slim and a Pandora battery, goto psp-hacks.com to learn how.
You can't update a psp without a working battery. It'll state that the battery is low and you need to charge it.
You need to unbrick your psp, for this you have to have the Pandora Battery and magic memory stick.
The short answer is no. The PSP slim "CAN" take the larger battery from the PSP-1000 series, but it sticks out and you need to get a custom battery cover for it. The PSP-1000 can take the Slim or PSP-2000 battery, but, the same logic follows. It's best to keep the proper batteries to the right console.
you will need a pandora's battery and a magic memory stick with DC installed. the guide is here: http://www.pspmod.com/forums/psp-hardware-guides/28839-easy-use-pandoras-battery-guide.html
Yes you can, the PSP battery will continue to charge even when you are playing. I would not recommend to do that, it is better if you leave it to charge and then play.
Downgrade your PSP system to version 1.5 by turning your PSP battery into a Pandora's battery. You need are an original PSP battery (with more than 50% charge) and a Memory Stick Pro Duo with 1GB memory or above Users can downgrade their PSP to version 1.5 because they can upgrade their PSP to any version from 1.5. If you upgrade your PSP to version 3.51, you can play any downloaded games and run any applications.
It's only possible to turn on your PSP with an adapter for the PSP or a battery for the PSP.
You do not need a cable to play between two PSP's
PSP Go can only download games and the PSP 3000 can download and play UMDs. If you need to play UMDs then the PSP 3000 is the choice but if that doesnt matter to you then go with the PSP Go.