2002 Porsche Boxter battery draw
Customer brought this Boxster to us to install a battery saver because the vehicle only gets driven about once a month and needs to jump start it sometimes. I check for a battery drain and found after a few minutes is down to about 115 ma drain, witch is high but after two hours everything goes to sleep. My question is, if it goes to sleep after two hours should I not worry about it, or is two hours to long for this vehicle? By the way battery and charging system is all working good.
Are you checking that 115 mA drain with the vehicle locked or unlocked? If unlocked, measure drain with the vehicle locked and the front bonnet latch manually tripped. Take note of an audible beep when locking the car.
In that case, yes, 2 hours at 115 mA draw is too much. When all is normal they typically draw about 35 mA depending on how the car is optioned. Is this vehicle totally stock, and no LoJack? Are you measuring draw in series, or inductively at the battery cable? What is the Ah capacity of the battery that is currently installed in the car? Is the battery lead acid, or AGM?
Also make sure you had now water entry into cabin, especially under drivers seat where the alarm module sits. If module is shows sign of corrosion, clean water drains in comportment next to battery, it has drains on either side of it and they get filled with leaves and mud.
I did check module under the seat, and there is no evidence of water or corrosion, thank you.
Ditto to what Sevan posted. You should also verify the battery is the correct size and rating for the car. It is also worth noting the battery is not a deep cycle type battery. Constant deep discharge damages batteries. It may pass a basic check but not have the capacity of new and the self discharge may be much faster than new. A maintenance charger may simply finish off the battery. Garage…
We are sure the battery is the correct one, we installed it two months ago but will double check on that, thank you.
If you have scan tool like piwis scan the car . Also check both windows make sure there up position. With both hood close make sure all light off.check alarm system
If it is going below 50ma after 2 hours and is it staying that way, asleep,? Then the 115ma for 2 hours is of no consequence. It’s not enough to be a problem. I more wonder what the scenario is when it is started? Is the battery brought back to full charge? I’m thinking that it’s not and that it is put back partially discharged. A couple months of that is enough to cause a no start.