How's it charging

[virgilmobile]

Haven't tried it yet , but here's the idea.Get one of the Digital automotive amp meters from Harbor Freight(Item #67724).It's rated for 30 amp.Unplug the 30 amp automotive fuse from the replaced dog-bone fuse,and plug in the tester.It appears to have a length of wire to the display so it could be brought up to a readable range.I suppose it could even be extended to the dash.Easier than #10 wire for the $4 meter.

[thrasherg]

That is a very reasonable thing to do, but you still need a fuse in the circuit and make sure you use heavy duty wire to wire in the gauge as you are adding quite a long length of wire (couple of feet) to the circuit which will cause some volts drop and that will weaken an already weak charging system!!

Gary

[virgilmobile]

I agree that adding a amp meter in the dash(old style)is not a good idea,because of the wire size needed .That's why I thought the digital one from Harbor freight might fit the bill.It appears to fit in place of a standard auto type fuse so there is no added wiring necessary.It is a current sensor,that takes the place of the fuse but maintains compatibility.It also is fused internal(30 amp),protecting the bike.off the adapter is a length of small wire that goes to the display.

[Steve F]

I was looking at this thing too, and was wondering about the fuse protection. It says something about the circuit still protected while in use, but how?
It looks to be a shunt type device, and a volt meter across the shunt, so the current to the digital part of the meter would be in volts and not amps, and a very small current at that too.
Looks like a neat little device, but I'm still wondering about the fuse protection in the circuit being checked.
Steve F

[virgilmobile]

I just picked it up $10 on sale.First thing I did was break the "probe"apart.Yes , it is a 'shunt' device.
There is a fuse holder in line with the shunt.It also states clearly "10 second test only"
I assume with 30 amp being drawn through the 3/4'' 2 conductor shunt bar will get it hot.I guess that the shunt is a bi-metal.
So my idea is to measures voltage drop across the shunt with a 5,10,15,20,amp draw with a DVM.
With that information I can translate that to a point on the wiring harness of the wing between the battery and charger.There is a voltage drop on that wire.It may not be accurate,but I'm more interested if it will show charge and discharge.
If this theory pans out,this may be as simple as cutting off the probe and hook it between the battery and a common load point.
Here's a pix

[virgilmobile]

I did some preliminary tests.This what I found.
1. there is a shunt bar about 3/4 " long that the meter is measuring across.
2.The display does not display either a charge or discharge indication,only amps,regardless of load or line connections.
3. The 2 wires from the shunt measurements are:
.011 vdc at 2.5 amp
.026 vdc at 5.7 amp
.034 vdc at 7.9 amp
Disconnecting the wire from the shunt causes a 2.7 amp indication(Internal biasing).
This seems to display on a linear on a graph.Perhaps I may find that the 12 volt wire that feeds the ignition switch also has a voltage drop I can tap into.I do not want to measure amps from the charging system,only the amps going to or from the battery.I'll DVM it tonight and post the results.
Still need to look at powering it from the bike(it uses a 12volt battery)and altering it to show a discharge or at least a 0 when discharging.
Voltages are very small,a blocking diode won't work.I'll think about it.

[virgilmobile]

Bought a harbor freight on sale $10 30amp digital meter.Unplugged the 30 amp fuse and attached the test probe.This is what I found...
10.2 amp discharge with key on and engine off.
15.5 amp charge at 3500 rpm.
3 amp at 1000 rpm.
as it ran for 10 minutes at 2500 rpm(9 amp) the charge rate slowly dropped as the battery approached a full charge.It finally settled down to 2.5 - 3.5 amp running from 1000-3000 rpm.

Because the meter does not show the difference between charge and discharge,I assume as long as it doesn't show 10 amp steady(bike load not charging)the reading is charge rate.

I tested this meter on both the gl1100 and the gl1200.
The gl1200 current drain was slightly less,and the charging the same.

Checked for a spot on the bike to hook the probe wires.I was looking for a hot wire that feeds the bike from the battery that has a voltage drop of .04 vdc with a 10 amp load.
Well I found that this thing has a voltage drop of .58 vdc from the battery post to the ignition switch.WOW.I'll pull the cover and find a place to attach the leads.
Also I verified that it can be powered from the same leads that it's testing.Cool,batteries not needed.
Lastly,about the 10 second test limit.Well, maybe a overheating problem with continuous 30 amp load,but running 5 amp it stays cool.