2 of my 4 vtech handsets keep giving me a 'check battery warning'

How old is the handset? Batteries last from 2 - 4 years and then can't retain a charge. In most wireless handsets the batteries are easily replaceable. Yours has a NiMH battery pack with a pigtail lead coming from it, google your model number + Battery for replacements

Instructions

1. • 1Remove the battery cover from the back of the phone. Most models have a door that slides downward to reveal the battery compartment.
   • 2 Install the battery by inserting the connector on the battery wires over the pins in the handset battery compartment. The connector will only go on one way.
     
   • 3 Insert the battery pack into the compartment and replace the battery cover.
     
   • 4 Charge the phone by sitting it in the charger for a minimum of 16 hours on the first charge.
     
   • 5 Place the fully-charged phone onto the cradle of the base unit and wait for the display to show "PRESS FIND HNDST 4 SEC ON BASE." If the message does not come up, lift the phone off the base and put it back in the cradle.
     
   • 6 Press and hold the "FIND HANDSET" button on the base unit for approximately four seconds. The display on the phone will change to "PLEASE WAIT," then "HANDSET X REGISTERED."
     
   • 7 Test the phone by making a call.
     

Power light indicators on flashing red as warning that battery is almost depleted of functionality. ascertain that devices with extension cables deriving power from elsewhere are plugged in to reattain power to acheive regular functionality. For example, devices with red light indication as power warning would also flash yellow or green when in full power charge from another source. refer with devices user guide or manual for refering, diagnostics.

The locate handset button will make the missing handset ring for 60 seconds. This will usually give you time to find it (assuming the handset battery is good, the handset is not out of range, and/or the handset ringer isn't set to OFF). Once you have the handset, press the Page/Handset Locator button or place the handset on the base.

You can press the locate handset button again if you haven't found the handset in one minute. The manual for the Vtech 2451 is available from Retrevo: http://www.retrevo.com/support/Vtech-t2451-Telephones-manual/id/470ag516/t/2/ . You will need to enter a code to download the pdf.

I hope this helps.

Cindy Wells
(If you have a large area or several floors to check, those 1 minute intervals aren't enough time to search for one person. Enlist assistance if you suspect the missing phone isn't just under a throw or pillow near the couch (for example).)

With vtech phone (many times) a beeping handset indicates a low battery or an inability to connect to base station. check to make sure the battery is connected correctly and that the phone is setting in its docking station correctly. (remover and obstructions that would prevent correct charging) If this fails go to your local store that sells batteries for cordless phones and purchase to correct type.

Find handset works by causing the handset, or handsets to beep when you push the button on the base unit, and until you find the handset and push the off button. If the handsets do not beep the batteries are probably dead.
We have a handset that flashes "Charging", and later, "Connecting", but it never connects. When the handset is removed from the charger the handset shows "Place in charger". By process of elimination I have determined that the handset has a problem. The problem is NOT with the battery OR charger. I hope this info helps you.
-Vector721

change battery and it will be ok

Place the handset in the charger and press find handset for 4 seconds.This will register the handset. do the same for other handsets.

I have the same problem.... not sure why it happens but in fact the battery has actually been charged. If you open the battery compartment, then unplug the battery and plug it back it will work fine. Quite annoying to have to do this all the time.

You are pretty close to the solution. The problem is the charge detection in the handset. All handsets on a cordless phone detect the battery level with an hexadecimal value in the memory. Each hex value equal a volt value of the battery. EX: 3.5v = 9B
3.6v = 9C 3.7v =9D etc... The problem is the hex value in your defective handset are all mess up. So 9B is not 3.5v anymore. Then your handset could last 1hr after foul charge or doesn't alert you before the phone goes dead due to low BAtt.