I have a 68 plate Kuga which has both sets of keyless keys. A few weeks ago we noticed that intermittently, and with both sets, the car would say ‘No key detected’ or wouldn’t always lock or unlock first time. Both keys have had new batteries. Could it be they just need re setting? 

Have you measured the 'new' battery voltage with a volt meter ?

There are very often problems with poor replacement batteries. A brand new good quality battery will measure at least 3.3V Once the battery voltage falls below 2.95V problems start to occur. 

Hi there, tbh they probably were a cheaper one (I didn’t put them in) but problems have started since replacing them. Will give it a go, thank you!! 

My 2018 Kuga has completely died 3 times in the last 3 months, I’ve not been   able to get into the car with the keys, so I had to enter via the emergency key. I changed the batteries on both keys but that didn’t work. I had to call the AA on each occasion to start the car. They told me the battery has died and to drive it around. I use the car more than enough to keep the battery charged. My car has been booked in 3 times with Ford (spent £120 for them to investigate) and they couldn’t find the fault. The car went in for further investigation today and the keyless entry isn’t working properly on the 2 front car doors. This is draining the battery. Ford told me they need replacing which will cost £640. I’ve had the keyless entry system turned off for the last month or so and the battery hasn’t drained since. I might just keep the setting off and see how it goes…. Very poor indeed.