battery :|

[bad_religion_au]

ok pokin around under the bonnet of the 40, the voltage (with car off) across the two battery terminals is 12V

now this is where it gets interesting, the voltage if i put the probes on the plastic case of the battery below the terminals is still 12 volts... if i put one probe next to the (-ve) terminal and one on the side of the battery (plastic) it reads 9 volts

if i do the same, but put the probe on the battery tray it reads 6 volts.

is this bad?

[chimpboy]

ok pokin around under the bonnet of the 40, the voltage (with car off) across the two battery terminals is 12V

now this is where it gets interesting, the voltage if i put the probes on the plastic case of the battery below the terminals is still 12 volts... if i put one probe next to the (-ve) terminal and one on the side of the battery (plastic) it reads 9 volts

if i do the same, but put the probe on the battery tray it reads 6 volts.

is this bad?

Is it all clean and dry?

[bad_religion_au]

it's dry, a little dusty but dry

[wayne74]

thats a strange one never seen that before have ya got the meter on the right circuit ac/dc maybe evn ya meter could be stuffed ,borrow a mates and retry it

[bad_religion_au]

meters on dc voltage, and it does it with a mates meter as well...

should i be scared

[DamTriton]

Nothing to worry about.

The digital meters only need bugger-all current to measure a voltage. What happens is with a bit of moisture and battery acid mist the ions in the acid act as a bit of a conductor (a resistor) down the side of the battery case, and across the top of the case too, (in reality a couple of megohms resistance - nowhere near enough to discharge you battery). Running one lead of the meter down the side of the battery essentially "taps" that resistance about half way down giving a voltage proportional to the resistance it is measuring.

Essentially like a demister fan speed controller on a very "lite" scale

Should be able to find strange voltages across all surfaces of the battery.