help reading multimeter

[Muddy42]

This is a 2009 Honda TRX420 quad.  I have been having some battery issues.  The battery was old so I've replaced it.  Now I am checking for parasitic draw from the system.  The quad had been turned off for ages and the electrics are pretty basic.  The multimeter is connected in series to the negative side of the battery.  I used the left 10A plug first. My manual says parasitic draw should be <0.01 mA

 

This is pretty basic. See picture below of my multimeter.  Is this 0.06 mA?

 

I always struggle with the units and greek letters for amps! when I move the dial the decimel place and units move around in a confusing way.

 

The multimeter goes to zero when I remove the main fuse.  No other fuses have an impact, so it'll be difficult to locate the issue.

 

Thanks

 

[Peter 1955]

I don't really have an answer as to how to find the fault, but I may have a solution. Why not simply buy a £10 battery isolator switch, and cut all possibility of current leakage when you're not using it? Simple but effective. 

[openspaceman]

1 hour ago, Muddy42 said:

No other fuses have an impact, so it'll be difficult to locate the issue.

Does it have bladed (car type) fuses? It is easier to check for parasitic loads by checking for a voltage drop across the fuse (fuses work by having a resistance that heats up and melts the fuse wire if too much current passes, current passing through the resistance causes a voltage drop across the fuse). There is a little pair of "windows" at the back of the fuse which are bare contacts that can be probed. Ifthere is a discernible voltage that circuit is carrying a current.

 

I suspect the current measuring on your DMM should be the left two sockets.

[TuscanPhil]

22 minutes ago, openspaceman said:

I suspect the current measuring on your DMM should be the left two sockets.

No, that's for the higher range  -10 A, the socket he is in takes up to 200mA.

 

1 hour ago, Muddy42 said:

Is this 0.06 mA?

 

Yes, to me, it would read such that 20mA (ie the range you are on) would show as 20.00, so yes, I'd take that as the square root of naff all current draw, so it would be 60uA.  What does it show if you go to the 2m and 200u ranges?  On the 200u range, I'd expect it to show 60.00 (or therabouts - might be 40, might be 80 - depends how good that meter is...)

[Muddy42]

1 hour ago, Peter 1955 said:

I don't really have an answer as to how to find the fault, but I may have a solution. Why not simply buy a £10 battery isolator switch, and cut all possibility of current leakage when you're not using it? Simple but effective. 

will do, if I cant find a fault

 

34 minutes ago, openspaceman said:

Does it have bladed (car type) fuses? It is easier to check for parasitic loads by checking for a voltage drop across the fuse (fuses work by having a resistance that heats up and melts the fuse wire if too much current passes, current passing through the resistance causes a voltage drop across the fuse). There is a little pair of "windows" at the back of the fuse which are bare contacts that can be probed. Ifthere is a discernible voltage that circuit is carrying a current.

 

I suspect the current measuring on your DMM should be the left two sockets.

Yes it has these fuses.  I think the left plug is for higher current up to 10A.  I'll try measuring at the fuses, but theoretically the reading should be the same.

 

14 minutes ago, TuscanPhil said:

No, that's for the higher range  -10 A, the socket he is in takes up to 200mA.

 

Yes, to me, it would read such that 20mA (ie the range you are on) would show as 20.00, so yes, I'd take that as the square root of naff all current draw, so it would be 60uA.  What does it show if you go to the 2m and 200u ranges?  On the 200u range, I'd expect it to show 60.00 (or therabouts - might be 40, might be 80 - depends how good that meter is...)

 

so is 1 uA = 0.001 mA and 60uA = 0.06mA.

the meter is cheap, sorry I cant remember what is was saying on those ranges, I was too baffled by the scale changing again.

 

so I have 0.06mA which is over the threshold of 0.01mA ?

 

 

[GarethM]

Has it got a alarm/immobilizer?

[TuscanPhil]

35 minutes ago, Muddy42 said:

so I have 0.06mA which is over the threshold of 0.01mA ?

 

Yes, it is , but 60uA is naff all in the real world.  I don; tknow what capacity battery the Honda has but say it is 40Ah (not the CCA figure on the battery), so 60uA into 40Ah give full discharge in 6666666 hours or about 76 years - I suspect if your battery is going flatter quicker than that, then you have a dud battery or issues elsewhere.

[Muddy42]

1 hour ago, GarethM said:

Has it got a alarm/immobilizer?

not a chance, even I could hotwire it!

 

37 minutes ago, TuscanPhil said:

Yes, it is , but 60uA is naff all in the real world.  I don; tknow what capacity battery the Honda has but say it is 40Ah (not the CCA figure on the battery), so 60uA into 40Ah give full discharge in 6666666 hours or about 76 years - I suspect if your battery is going flatter quicker than that, then you have a dud battery or issues elsewhere.

 

thanks.  I think the problem is that battery health is not linear and that even partially discharging it can cause damage.  Its a new battery and I've replaced the rectifier regulator.  The wider issue is my stator is weak - only about 15v to 33v AC (idle to mid rev), pre rectifier in each of the phases when it should be 18v - 60v ish.  That said I am getting 14.3v - 14.6v DC whilst driving around which should charge the battery.  I've put in a voltage meter and I'll keep it under review for a while and trickle charge.  

[kram]

I recommend getting an Imax B8, B6 or the various off brand clones (of a chinese item). This is intended for RC lithium charging but it will also do a very good job of lead acid, telling you exactly how much charge has done in, how much was in it with a discharge test.

 

Generally Pb batteries are over rated abot 4x becuase of the way they degrade, this makes them last about 10x longer than if a smaller battery was specified.

I generally say if measures at 50% capacity its time to be aware of future problems. At 25-40% you can expect problems if you leave lights on or dont give it ample chance to recharge. Below 20% you should expect problems, keep a jump starter with you and consider replacing.

 

However theres little point replacing one if it will be used once, left to discharge for three years and then need replacing again.