I never thought I would need to join a Mazda forum because Mazda are usually so reliable but here I am. Due to the COVID19 pandemic my 2017 Mazda 3 (automatic) has been sitting idle for much longer than normal, sometimes 1 week or more. When I come to start it the battery is too week to turn over the engine to start. I measured the battery current after shutdown with doors closed everything turned off. I measure 1.3 AMPS current, clearly way too high and is draining the battery. I checked fuses and found that only the interior light circuit and the transaxle controller fuses caused any drop in current. With both these fuses removed I still get 0.11 AMPS. This still seems high, does anybody have any thoughts on what it could be?

 

How long after locking the car are you measuring current draw? Car can take 5 minutes to fully go to sleep. After that, anything over 0.05amps is too high.

 

thanks GR I did not note the times but I will repeat the tests today.

 

I ran some more tests on the battery current after closing the doors. The first test was with the doors unlocked, doors closed with the key fob inside the car. T=0 (after interior lights go off) 1.3 AMPS, T=6 minutes 0.24 AMPS, T=7 minutes 0.01 AMPS. With the doors closed and locked and key fob placed remote location T=0 1.3 AMPS, T=1 minute 0.24 AMPS, T= 2 minutes 0.01 AMPS. So even if I left the doors unlocked and key fob inside (which I did) I would not expect that 6 minutes of 1.3 AMPS then a minute of 0.24 AMPS would cause a battery to discharge in a week such that it would not crank over the engine.I guess I will avoid leaving car unlocked and remove the key fob and see how it goes.

 

Just to get some closure on this item. I parked the car for 4 days with the doors locked and key fob remotely placed. After 4 days the battery voltage dropped from 12.88 Volts 12.77 Volts i.e. a 0.11V drop. It seems to me that parking the car with the key fob inside and doors open was responsible for the weak battery causing it not to start. Maybe the car "wakes up" periodically with doors unlocked and key fob inside and pulls a few amps for a while then "goes to sleep"? Anyhow I am locking it up from now on.