Smart key remote is slow acting and will not allow starting up the vehicle. Can the battery in the Smart key be replaced; and how? Does it have to be re-programmed?

try another key. the vehicle is equipped with a "smart key", the one you are using may be bad and not signaling the security system to allow start-up. The solid red means the vehicle is not reading the security chip in your key.
If you have another key try it.
Is the battery and connectors good? Low cranking amps will not signal the security system to shut of.

Often, you need to press the unlock button on the remote twice. First press unlocks the door and second press disables the immobiliser and allows the vehicle to start. The key alone will not start the vehicle.

Alternatively, when the key is in the ignition - press the remote unlock again.

The remote acts as an immobiliser device. The reason your car won't start on the key is probably because the system won't allow any key in the ignition - it is preventing theft of the vehicle. Once the unlock button on the remote is pressed the system then recognises that key is the legitimate one for the vehicle and the disables the immobiliser and allows you to start the car

BAD FOB?
or battery weak in fob?. replace them?
always have 2 fobs, so you can isolate problems and not get stranded.

is running engine charge lamp out?

or the button on the fob, panic, is bad,
to prove this take the battery out of FOB in use
and use the spare fob with fresh battery.
this proves its the fob, see how?

What they did was upgrade the system here try this its from Kia.
Turn the ignition key to the "ON" position. Reconnect the negative battery cable. Turn the ignition key to the "OFF" position.
4. Transmitter Programming Procedure:
1. Turn the ignition key to the "ON" position. Do not start the engine.
2. Locate the "disarm/programming" button which is secured to the remote start wire harness behind the left lower dash panel.
3. Press and hold the "disarm/programming" button for 10-15 seconds until the horn beeps 3 times.
4. Release the "disarm" programming button.
5. Press the red Find/Panic button on the remote start transmitter one time. The horn will beep one time indicating that the transmitter code has been learned. Repeat for each additional transmitter.
6. Turn the ignition key to the "OFF" position.
5. Function Check:
Refer to the vehicle specific "Remote Engine Start" installation instructions for a complete list of functions to be verified before delivering the vehicle.

Have you replaced the Batteries in the remote control??? Does your vehicle require a "smart" key???

X-100+ Auto Key Programmer is a handheld device for programming keys in immobilizer units on vehicles. This scan tool has a simple and robust design, to make your vehicle service experience much easier!

He should have his key checked at a dealer, as it may have had its smart chip damaged. The key would allow entry and most operation, but will not allow the vehicle to start. Make sure to take the VIN. A second key would verify if the problem was the key itself. He should have a second key.

most chargers have a few different settings you want to put it ona slow charge for about 4-6 hrs bye slow charge I mean it should have a 2amp or a3amp trickle charge unless you are attempting to start the car immeditly the you will you the setting labled starting

Try your spare key first. also, does the anti theft visual indicator (red flashing light) prove out, that is light for three seconds when key is turned to on.

here's some info.

Principles of Operation
The passive anti-theft system (PATS) uses a specially encoded ignition key. Each encoded ignition key contains a permanently installed electronic device called a transponder. Each transponder contains a unique electronic identification code out of over 18 billion, billion combinations.
The passive anti-theft system (PATS), also known as SecuriLock ®, uses radio frequency identification technology to deter a drive-away theft. This system is known as SecuriLock® in North America, Safeguard® in the U.K., and PATS in continental Europe. Passive means that it does not require any activity from the user.
The SecuriLock® System (PATS) is not compatible with NON-FORD remote start systems, which allow the vehicle to be started from outside the vehicle. These systems may reduce the vehicle security level, and also may cause no-start issues. If equipped, the remote start system must be removed before investigation of PATS-related, no-start issues.
Each encoded ignition key must be programmed into the vehicle's powertrain control module (PCM) before it can be used to start the engine. The correct ignition key is a different design than prior model years. Consult the Rotunda Key Ordering Guide for the correct part number. There are special diagnostic repair procedures described in this section that must be carried out if a new encoded ignition key is necessary.
This system contains a new feature named Unlimited Key Mode. This feature allows a customer to program more than eight keys to the vehicle if they request it. Each vehicle in Unlimited Key Mode is set up with a special unlimited transponder security key. This allows all the customer vehicles to share the same keys, but no other keys from outside can be used to operate the vehicles. For an individual customer, any randomly selected security key is acceptable. Refer to Unlimited Key Mode Programming in Key Programming Switch State Control in this section.
The PATS transceiver module communicates with the encoded ignition key. The module is located behind the steering column shroud and contains an antenna connected to a small electronics module. During each vehicle start sequence, the transceiver module reads the encoded ignition key identification code and sends data to the PCM.
The control functions are contained in the PCM. This module carries out all of the PATS functions, such as receiving the identification code from the encoded ignition key and controlling the engine enable. The PCM initiates the key interrogation sequence when the vehicle ignition switch is turned to RUN or START.
All elements of the PATS must be functional before the engine is allowed to start. If any of the components are not working correctly, the vehicle will not start.
PATS uses a visual theft indicator. The indicator will prove out for three seconds when the ignition switch is turned to RUN or START under normal operation. If there is a PATS concern, this indicator will either flash rapidly or glow steadily when the ignition switch is turned to RUN or START. The PATS system also flashes the theft indicator every two seconds at ignition OFF to act as a visual deterrent.
PATS will be activated and will disable the vehicle from starting if there is:

• an incorrectly encoded ignition key.
• a damaged encoded ignition key.
• an unprogrammed key
• a non-encoded key (key has no electronics).
• damaged wiring.
• a damaged transceiver.
• a damaged PCM.

you can try switching the key to the "on" position then open the hood and disconnect the negative terminal of the battery and reconnect after 2minutes. this will allow the alarm to be '"reset" and will recognize that you have the key for the vehicle.