At&t phone model E5908 new battery now says can't connect

AT E5908 User Manual

You will need to go to the AT&T product support website and if the manual exists online it will be there in pdf form.

My mother's portable handsets needed battery replacements, and since the older model required harder-to-find, more expensive batteries, we opted to get her a whole new set. These are fairly light weight, but feel sturdy. All batteries and necessary equipment was included. The base has a nice handset location feature - when you press the button, all the handsets will make tone noises so you can find them and will continue to do so until you've seated all handsets in the cradle or until you press the button again. Other sets I've seen really required two people - where one would have to keep pressing the button while the other person did a hunt-n-seek. This is far more practical if you're home alone and/or live alone and have misplaced a handset. There are 10 ringtones available - these are the loud MIDI type tones, not the pretty melodies you get on an iPhone - but they range from loud ringer to melodic and each handset can be set to a different volume. The base station needs to connect to a phone line, but the other handsets need their bases connected to power only. This is a great feature for those who live in older homes where the phone jacks are few & far between... and gives you more choices on where to locate a phone. My mother & I have conversed on the phone - she can hear me really well and vice versa. So far, the units have a very acceptable battery life before draining enough to cause noise. This is a nice ensemble at a very reasonable price.

The USB wireless stick uses the cell phone network for wireless Internet connection provided it is within that ISP cell phone coverage area.
I doubt you can use a 2nd hand USB wireless stick unless the service is transferred to you. It is best you organise your own Internet connection with a ISP of your choice.
Laptop battery are removable and can be replaced when they are worn out, BUT the BIOS battery is inside the laptop and this can be changes but requires getting access to the insides of the laptop.

If you are talking about the compartment on the right side of the base of a Motorola M681, then you do not have to connect anything. You can add an optional battery (the same battery pack as for the handset) to keep the phone working for a few hours during a power failure. (If the wires have been pulled loose, than the backup battery might not work. However, I'm not familiar with the wiring for this model.) The handset battery must be properly inserted and charged for that to work.

You also must plug in the AC power cord (to the phone and a good outlet) and the telephone line cord.

I hope this helps.

Cindy Wells

found answer in instructions

If you are a US resident, you can probably take them to Radio Shack. They can probably find one compatible with your phones. You'll pay too much there but save some time since there are dozens of different connectors and polarity is important to avoid damage to the phones.
Trying to buy this kind of accessory from the company whose name is on the device is hopeless since none of them seem to support the products they sell probably because they don't make them either. 

check the jack with a different phone that you know works.

I had the same problem. I unplugged the base unit for several minutes. When I plugged it back in, the base unit reset itself and the handsets reset themselves to the base unit. You will have to reset the clock and any other features you use. My phone is a model E5908. Hope this works for you. Goos luck.

I have the very same problem and it was after storing numbers into the directory, although that may not have anything to do with it.