I had my transponder replaced, and when i connected the battery to my car that had been on charge overnight i connected it the wrong way, now it wont start

Sounds like your new battery is flat. Try this. Sit someone in the car with the headlight on. Stand in front of the car and look at the headlights. Have the person in the car try to start it. When you hear the click, do the lights dim to a glow worm? If they do, your battery is flat. Whenever I get new batteries, I charge them overnight with a 6 amp charger.

Or when you reconnected the battery, the key wasn't in the ignition, and now your anti-theft is activated because it doesn't recognize the transponder in the key.

Check altanator

You will have to program you keys to the immobiliser in the car. The keys transmit a code to the immobiliser in the car and if you have fitted anew ignition switch you will have new keys with the wrong transponder. You may be able to fix it by replacing the new transponder in the new key with the old transponder out of the old key

If the battery is working, it may not be charged up enough to actually turn the motor over. You may need to charge it overnight.-----------------------------------------------------------------------------------
auto HID Xenon light

dear,

the battery is not fully charged i guess............get it recharged overnight and try for the same.

thanx

You may have a bad alternator... you can have it checked at any auto store for free... Also check your positive/negative wired connections...your connection to your positive cable that goes to your starter may need to be replaced, or your negative cable could be bad also.

Could be, have the battery LOAD TESTED and also verify that the alternator and the connections are good.

try checking the main relay under the dash