Battery and brake light came on during ride home.

If you have a multi-meter check the battery voltage at the terminals of the battery 12 v dc or better indicate that the battery is nearly fully charged.
no meter no problem. Turn on the head lights and look into the light and if the light is dim and flickers the battery is either weak or needs a charge. If the car will not start and you are able remove the battery and take it to Auto Parts store of choice. Have them do a full diagnostics. They may need it for a while to recharge the battery before checking. If battery is bad replace. If not charge battery and take car to favorite garage. Remember not to depress the gas pedal after battery disconnect. If you do the engine electronics will have to relearn idle. Some times the engine will continually stall during the relearn process. Better to leave the pedal alone during battery replacement.

If the car starts take it to a Auto Parts store and have them check the battery and charging system.

I expect that a CD is stuck in the radio or a light switch was left on

• Dome
• Fog Light
• Head Light
• Brake Light (bad switch)
• Flashers
• Cooling fan thermostat (bad thermostat)

What has happened is that the battery has run down and as the battery sits for a few seconds voltage comes up and light goes on. With light on battery voltage goes back down and relay clicks. Of course this will discharge the battery.

You may have a bad alternator which is still charging but not regulating current. The electrical spikes will throw off the ABS module and other computers in the car. Have it checked ASAP before it causes damage to thee PCM.

Since the battery light was 'on', it seems the vehicle's charging system has failed.
Get the charging rate, and probabley the alternator will need overhauling.

Try a day time running light modual,these things are notorious for messing up,and since they are supposed to work when the car is charging it seems like the logical solution.

GET YOUR BATTERY LOAD TESTED ALONG WITH YOUR ALTERNATOR TESTED FOR OHMS VALUES AT THE REGULATOR. ALSO MEASURE THE VOLTAGE WITH ALL LIGHTS, AC, RADIO ON. SHOULD BE THE SAME AS BATTERY OUTPUT.

1. Are your alternator belt lose???
2. Sound like your alternator is not putting enough amp out at idle. Have someone check your alternator out.

Hi, No model of vehicle or year both would help!
sounds like you need to ensure the back light is never left on before leaving the vehicle. you need to check the tension on the brake light switch or replace the brake light switch normally under the car without full details hard to state where brake switch is located. Please leave me feedback, Malcolm Campbell.

any ck engin lights could be bad gas or spark plug or coil pack braking down

Sounds to me like you have a weak batt. also if you rear lights are sticking on some times that could drain it