Amp Meter

[bc1]

I have thought about replacing the air temp gauge on my 03 Ultra Classic with a quality amp meter. I want to see the actual amps being sent to the battery, not just the volts. Has anyone done this? If so, how/where did you wire it up?

[PoorUB]

Really volts gives a better idea of charging that amps. If the meter reads 14-15 volts the battery is charging. amps will vary with various electrical loads, and the condition of the battery.

If you want to go a head with this I would put the amp meter between the regulator and battery. It will read a accurate electrical load on the whole system. I have seem people install amp meters in other places in the electrical system and get pretty much garbage for information. Keep in mind you will need to run a 10-12 gauge wire up into the fairing and back or find a meter with an external shunt.

[wholehog]

shunt is the only way to go....

[bc1]

Thank you for the replies. I want the amp meter to tell me the load on my system, and a better idea of what's happening to the system. My volt meter has been reading 15 volts most of the time. That's on a fairly new, (2 year old) HD battery.

If I see the amps I can tell better what's happening.

[gordonr]

An true amp meter traditionally will be your worst friend. Besides if and when it has construction issues or wiring conn problems later on it will leave you stranded because all your electrics have to pass through it to function properly (except the starter) . Another issue, say when your battery starts going bad the amp meter will virtually show no charging amps either. Pulling amp meters and bypassing back in the day was very common procedure to do then the manufactures wised up and moved on to voltmeters and shunts with way less problems.

[bc1]

Interesting comments Gordonr, what you say makes sense. I'll have to ponder on your comments and perhaps come up with a different solution.

[r0de_runr]

You might try a temporary clamp on inductive amp meter.  It wont harm anything, just insert it around the + battery cable.

[bc1]

Thanks r0de_runr, good idea. I have one for auto's. You place it over the positive cable, and it shows the amps flowing through the cable. That's what I'll do, forgot all about that gadget.

[gordonr]

Keep in mind the clamp should wrapped around the regulator output back to the battery to get actuals when running. Wrap the clamp around the battery cables for starter current draw tests.

[sfmichael]

Keep in mind the clamp should wrapped around the regulator output back to the battery to get actuals when running. Wrap the clamp around the battery cables for starter current draw tests.

  + 1  roger that 

when you guys mention shunts, what's that all about? 

[boooby1744]

You'll spend time lookin at that gauge,bad "Potty mouth" can happen. Keep yer eyes on the road.........

[mkd]

Bc1!  I took the temp gauge out years ago and installed an oil temp gauge in it's place.  Between the mobile 1 20w 50 vtwin oil and a good tune I rarely seen Temps above  180 degrees.  never gave any thought to an amp gauge. new battery every 4 years takes care of the electrical.

[chief-z]

Harley volt meter can read high by 1/2 volt and still be within Factory specs. also with a good charging system and looking at the meter in the fairing (from the saddle) it will most always read 15v due to the angle you are viewing. Put a voltmeter across your battery to get the actual volts that are being pumped into it for a better indication the figure that correction into your volt meter in the fairing. Send me the money you save as i'm almost out of beer!

[wholehog]

when you guys mention shunts, what's that all about? 


[attach=1]

a shunt is a very precise low resistance conductor through which all of the current flows....the ammeter actually measures the voltage drop accross the shunt and reads out amps as Voltage drop / shunt resistance

there are clamp-on DC ammeters that use a Hall Effect semiconductor to calculate current but their accuracy is dependant on orientation to the current carrying conductor....a shunt doesn't have this problem since all the current flows through it rather than magnetically coupled to it

a clamp-on ammeter is generally an AC measuring instrument that operates on inductive coupling similar to a transformer

[Hoople]

Kw tests.

  when you guys mention shunts, what's that all about? 

Another Big advantage for shunts that wasn't mentioned is that the shunt & meter can be connected over long distances using thin gauge wires.  You can install the shunt in the exact spot where the current needs to be monitored and the meter can be 50 feet away using 24 gauge twisted pair phone wire. In some cases that can be a huge labor/money/performance advantage. Even on just the length of a bike, not having to run a pair of 10 gauge wires to a meter is a relief.

[gordonr]

when you guys mention shunts, what's that all about? 


[attach=1]

a shunt is a very precise low resistance conductor through which all of the current flows....the ammeter actually measures the voltage drop accross the shunt and reads out amps as Voltage drop / shunt resistance

there are clamp-on DC ammeters that use a Hall Effect semiconductor to calculate current but their accuracy is dependant on orientation to the current carrying conductor....a shunt doesn't have this problem since all the current flows through it rather than magnetically coupled to it

a clamp-on ammeter is generally an AC measuring instrument that operates on inductive coupling similar to a transformer

Nice pic and explanation 

[clawdog60]

My understanding is you have to have an amp meter in series on positive side of dc load for
accurate readings. Shunt 

[Hoople]

My understanding is you have to have an amp meter in series on positive side of dc load for
accurate readings. Shunt 

No.  Current flow amount is the same anywhere in the loop circle. At the battery, at the load, at the switch, negative side, positive side, will all be the same reading.