my battery kept going flat on my peugeot 206 so l was told to replace the battery,My brother replaced the battery for me but know l have no power what so ever,No ignition lights and l cant even lock my car with the keyfob or manually with the key,What do you think we have done wrong!

you have the cables hooked up backwards, or did you take the plactic covers off the terminals on the new battery? remember red is + positive and black is - or negative

What you've done wrong is bought a peuget 206. Those cars are notorious for their electrical issues..there just one step above an alfa romeo which are the worst. Check the alternator though, also you could have a short some where in the system which is draining your ''power''. Or check and make sure all the lights are turning off when you do get it started. Possibly a dome light or engine bay light is staying on. Good Luck

The key fob has its own little battery. AND when you disconnect and reconnect a battery in the 206, you have to reprogramme this and that..
l think you turn the ignition key to position 1 and wait a few seconds..blah blah...its a big deal when you replace a battery.
BUT.. the keyfob has its own battery too. There is a sequence you must go through when you replace THAT battery as well..

Time to look in your owner is manual.

make sure u have the battery connected the right way for a start and then if its ok check the earth strap that runs between the body of the car and the engine or gear box usually other than that check that your main fuses are ok these are usually located under the bonnet