When the battery terminals are on, stuff will be trying to draw from the battery hence the low reading
hi everyone. i'm having some trouble with the battery in my hiace van
the car has been sitting around for at least a month or 2. but i'm having some trouble with the battery.
i realised the battery must have gone flat when i put my alternator back on the engine today. went to turn the car over and there was nothing. no lights or anything came on. so i got out the battery/trickle charger and connected it up
was looking at it with my voltmeter. and got some wierd numbers:
with out the charger and with earth and + hooked up. was getting .003V or something
with the charger and earth and + got 3V
with out the charger and earth taken off got 9V
with the charger and earth taken off getting 11 - 12V
so how come i'm getting no volts when the earth and that is all hooked up. but as soon as i take the earth or positive off i get 8 - 9volts? i obviously need to let the battery charge a bit more but was just a little confused as to why it was doing this?
As they say in the book, assembly is the reverse of dismantling, but slower cos you forgot where all the bits are
When the battery terminals are on, stuff will be trying to draw from the battery hence the low reading
I am the sun
Completely disconnected batteries can show 10-12V and then completely die under even the smallest load, usually either the battery is extremely discharged or it has dropped a cell or two.
AE102 - Charlene the Old Faithful, Reborn
JZZ30 - Lexi the Spacecruiser, 1JZGTE>>3SGE. 200rwkw, hunting Skylines and n00bs in SS Commodores
ST162 - Charlie the non-ghey Celica, 3SGE>>4AGE. GOOOOOOOONE
AE82 - Rosie the Bitsa from Hell, 70.8kw atw. Has been converted into garage space and money at last
KE55 - Billie the Beast, sadly missed
it might also give you a reason why the battery is fully dead, something might be draining it since you have next to no volts when + - hooked up.
Best to take your battery somewhere and get it tested. battery shops, auto stores will do it on the spot for free.
if you know any one with a battery charger . chiuck it on for like 2 hours and then try it again... check the reading after like driving a bit and it it slowly depleting then your batts gonee .. wreckers got em cheap . eg pick and pay
Have the battery tested or test it yourself.
1. Charge your battery first using your trickle charger. It may take a few hours. Charge it until its indicated as fully charged on the charger or if the battery is equipped with a 'magic eye' this should be green. Just for safety, no sparks or flames near a battery that's on charge!
2. After its been fully charged, check how much voltage its got. If you have (or can borrow) a battery load tester use it. Otherwise leave your voltmeter hooked up and crank the engine while paying attention to how much voltage the battery drops down to (while cranking till it starts). If it drops below 9 or 8 volts the battery is stuffed.
3. While its running, you might as well check your alternator charge rate (should be 13 or 14V with no electrical load on).
4. If you know your battery is still good or have replaced it but keeps going flat, something may be draining it. You can do a current draw test using the AMPS section on your multimeter (switch black lead from COM to AMPS) connect in series to negative battery terminal. From memory a car fitted with a lot of electronics should not have a current draw of more than 80milliamps but it depends on what the factory workshop manual spec is for your car. If its more than what the spec is, start removing fuses one by one to eliminate which part is draining your battery.
Hope this helps.
Bookmarks