battery going flat but battery in a good state
 

I bought the mazda 2nd hand and it has front and rear parking sensors and also a small switch inside the car to turn them off manually.

Im wondering if anyone has any problems with them.

My battery has gone flat 3 days running, I had RAC out today to start the car and they did a battery test. While they connected the tester it kept picking up that something in the car was switched on even though the key wasnt in the ignition and everything was switched off. Because I park next to a wall if the ignition is on then the parking sensor goes off, when I manually switched it off and he attached the battery tester again it didnt pick anything up 2nd time round.

I am wondering if maybe the sensors arent actually automatically switching off and thats why my battery is going flat. The battery tester said that the battery is good and therefore it doesnt seem as if its because a new battery is needd.

Could it be the sensors Or can anyone think of anything else that may be making my battery flat?

RE: battery going flat but battery in a good state
 

shouldve said its a mazda 5

RE: battery going flat but battery in a good state
 

If you needed a battery jumpstart to start the car, then the battery was dead and needs to be charged. A common myth is that you just need to drive around town to recharge the battery. In truth you would have to drive hours and burn a tank of gas to fully charge the battery. And doing so isn't going for the alternator either. Bottom line - if you have a dead battery, get it recharged or buy a new battery if the battery is 5 years old or more.

RE: battery going flat but battery in a good state
 

there may be a short that is causing the battery to lose charge. charge the battery or jump start it to charge a little, kill the motor, and take the positive mount off of the positive post. put it back on and check to see if there is any spark. if there is a spark, you have a short. anything that comes on even with the car off is designed to have a "soft start" sequence where it won't arc and cause the battery to spark.

if the battery has gone through more than a few extreme summers or winters, go ahead and replace it, no matter the age. i have seen batteries last for years when treated properly, and i have had batteries that have only lasted a year from having to start a motor 5 or 6 times a day during an extreme summer.

RE: battery going flat but battery in a good state
 

Im happy to replace the battery if thats all that needs doing. It just seemed odd that when tested even before it was charged back up the battery tester said it was in a 'good' state. I just dont want to buy a new battery to find that the sam thing happens again because I havent found the reason why the battery was going dead.
The bloke from the RAC said that in his opinion the battery was fine and something in the car was using power even when the ignition was switched off.

RE: battery going flat but battery in a good state
 

Any car these days draws some power when it is switched off. You don"t say how much and whether they thought it excessive or not.
There are radios w/a memory, ignition disarming systems, key recognition systems, ECU/PCM's (the computer or computer that control or track nearly everything in a new car,) air bag/seat belt controllers, perhaps an alarm or remote starting system, and the list goes on and on. These items all draw a few milliwatts each to do what they are supposed to do.