X5 E53 battery voltage sudden drop to 5v ?

[hellgrace5]

Hello.The car was starting/cranking good when i reverse the car and park it to car wash.When finish car wash i tried to start but no crank at all. no engine light sign, no headlight, no air cond, no horn etc. looks like all electronic went down.went to measure the battery voltage and it shows 5v only. i measure the battery terminal and the terminal provide infront the engine bay. I am very shock cause the battery just went down like that.battery is 1 year old.help !

 

[jarance]

check the connection at the battery terminals. It could be loose.

 

[hellgrace5]

battery connection is tight and i measure the voltage straight on the battery terminal no the battery clamp

 

[pratt]

Did you wash the engine bay? Possibility of water seeping into the battery area thus short circuiting it?

 

[hellgrace5]

the battery is at the back of the boot where the air suspension pump is.

and i din't wash the engine bay

problem solved.

the battery was dead. i jump started it this morning and is working fine now.

it is weird because i only left the car for only 15 minutes ? 12v down to 5v without anything on

 

[jarance]

May I know what is the brand and rating of the battery that was used to replace the old battery.

For a battery voltage to drop from 12V to 5 V, it could be due to many reasons:-
1. shorting somewhere
2. battery electrolyte running low
3. battery is damaged to due overcharging (faulty alternator or regulator)
4. faulty battery due to manufacturer defect.