electrical test ?

[Guest]

I am trying to figure out what is draining my battery, I removed the neg. ground and connected my digital multi meter between the ground on my battery and the disconnected ground wire. On "dc" it reads 12.50 volts, when I change the meter to "dcMa" it reads .001 which setting am I looking for.

[Steve]

When you switched your meter to DCMA, did you also move your leads?

Most meters use different inputs for volts and amps.

And, if you are actually reading .001mA, there is no drain.

If you are stating with 12.5 volts, your battery is not fully charged.

How long is it taking to "drain the battery", and to what level?

Which bike you working on? Won't matter much, but always nice to know.

.

[kdo58]

yes I did take the leads off when doing the different test.
My battery charger will only charge my battery to 12.50 volts than turns itself off.
The bike is 79 gs850
The starter drags and I have to kick start it.
If I turn the key on and put a screw driver across the starter solenoid it cranks the same.

[tom203]

yes I did take the leads off when doing the different test.
My battery charger will only charge my battery to 12.50 volts than turns itself off.
The bike is 79 gs850
The starter drags and I have to kick start it.
If I turn the key on and put a screw driver across the starter solenoid it cranks the same.

A decent battery charger will push battery to 13.3 volts (once disconnected it will fall to 12.6 ), which is what's needed to overcome the resistance of a 12 volt battery. Can you try your charger on another 12 volt battery to see what happens.

[Normk]

The only indication which is useful is the dcMa one indicating, essentially, zero current flow which means zero parasitic drain.

Steve's mention of the correct lead positions into the meter is an excellent point and one which I never think to mention as it seems obvious. You can see that we keep him around for more than his good looks alone.

When you connect the voltmeter in series with the battery, the indication is essentially meaningless because the circuit required to allow an electronic meter to indicate voltage is microscopic. You could place a 10,000 ohm, 1/4 watt resistor in series and likely read the same.

The procedure for identifying the cause area for a battery going dead is to charge the battery and leave disconnected. If the battery goes dead on its own then it is internally discharging. The other 1/2 of that test, is usually only performed if the battery does not self-discharge but should always be done, is to use an ammeter in the manner you stated to indicate parasitic draw. Parasitic draw is considered to be current flow from the battery when the key is off.

You are both brave an optimistic to have connected into that circuit on the milliamp scale as any significant drain would be in the single or double digit amps or 1,000 times as high. Any drain of any significance would blow the meter or meter's fuse.

Under what conditions does the battery drain?

Does it drain while parked or while riding? These are likely to have different causes.

[kdo58]

it drains when parked,
I tried my battery charger on a different battery and it charged it to 13.5volts, I am thinking it is the battery, I have left the battery unpluged after charging it and it lost half of its voltage.

[tom203]

it drains when parked,
I tried my battery charger on a different battery and it charged it to 13.5volts, I am thinking it is the battery, I have left the battery unpluged after charging it and it lost half of its voltage.

Sounds very likely!