We are having similar problem with vtech 5808

Hi it sounds like the problem is with either the base unit board or the board on the phone.
Do you have one main phone plugged into phone socket and the other two are extra phones that just plug into mains and pick signal up off the main phone if this is the case then the problem will be with the main base unit.
So first thing i would do is check the cable to the phone from phone socket is secure and hasnt been trapped under furniture or somebody triped over it and damaged the wire.
If this is not the case then the problem will be with the base unti itself and as the waranty has ran out this usually means that the phone was only really supposed to last untill this time this is the same with most electrical unit you buy.
The problem could be something as simple as a bad solder on the main board near where the signal is sent from the base.
I would say that the actuall phone is not to fault because if the main phone was at fault then the other 2 would work fine.
If you are ok at taking electrical units apart and can test the board near the signal output on the base it might just be that the solder has failed after this time.
If the phone works for a short while before it dropps the calls then it more than likely is a solder problem the thing is it is difficult to get a spec sheet for these phones i will look and if find one let you know.
Have you tried plugging a different phone into the phone socket to eliminate a problem at the phone exchange let me know how you get on and ill let you know if i find anythnig for you ok

General - Product Troubleshooting - VTech® Cordless Phones

www.vtechphones.com/support/.../35/178

VTech Communications Inc.Step 1: Place the handset in the base or charger. If PRESS FIND HS 4 SEC ON BASE does not appear on the screen after a few seconds, lift up handset and recradle it in the base or charger. Step 2: On the telephone base, press and hold FIND HANDSET for approximately four seconds.

Product Registration - VTech® Cordless Phones

https://www.vtechphones.com/.../product-re...

VTech Communications Inc.Vtech DECT 6.0 cordless phones are among the most advanced and innovative homephones on the ... Product Registration. How do I register my product?

vtech cordless handset, how to register - YouTube

? 3:21
https://www.youtube.com/watch?v=dV9rZ_cYcks
Feb 22, 2015 - Uploaded by Brian Williams
i registered my handset but im not able to call and answer call from my ... you lose your phone you have to de register allphones and start over.

Lithium batteries can be charged whenever you want for however you want. It is best to charge the phone overnight. you cannot overcharge the battery, and you do not need to deplete it before recharging it. Older batteries had a problem in which improper charging would damage them, but this kind of battery does not. Best of luck!

You should wait at least 2 hours before using it so that it can properly charge

you have first to page the phone on basis set then you can use the hand set

If the other three handsets work ok then you have a defective handset.

is your phone about a year old? It may be the battery. The vtech phones have weak batteries that clunk out after about a year and you'll get dropped calls, looking for base etc... The phone still appears to be working and the battery indicator tells you it's charged, but the battery is too weak to keep the wireless connection going.

Had the same problem and replaced the battery. budgetbatteries.com had the cheapest ones. But it's a knockoff, so I don't know how long it will last. So far it's been 3 months and the problems are gone. I would try that first and see how it goes. I paid about $15 including shipping. If you buy it from vtech it's at least double...

Got a wireless router? Change channels on the router off Ch6, the default channel and that may help your phone communication to the base station. I have had wireless phone customers lose their wifi when their phone rings, same frequency or intereference on that frequency.

This model of phone have serious problem regarding the battery. This phone use a lot of juice out of the battery. I'm pretty sure that when your battery is foul charge it doesn't do it. So the problem is in the handset. When your battery starting to get to low you loose your connection. Why?...Because the detection to LOW_BATT in your handset is not calibrate adequately. So it thinks that the batt is weak, to weak to make a conversation.

The other problem could be that your handset doesn't really foul charge your battery. So when you are to far from the base or talking for to long . There's not enough power in the battery to raise the output signal level(db) to your base.