VOLTMETER - The Importance Of Having An On-Board Voltmeter

[rogerc60]

I have one similar to the top one mounted in the glove box cover of my 2003 RT, powered from one of the wires intended for the radio (which is not there). Mine doesn't have the power switch. It is powered unless I turn the key to the Lock position, which I almost never do (so the device is nearly always powered on). In the 2+ years I've had it on the bike it has not caused any noticeable battery drain.

That "waterproof" cover may not be perfectly water tight. The first such unit I installed on my bike was ruined within 6 months by water ingress. The replacement unit must have a better fit, because it's lasted for almost 2 years without problem.

 

[Omega Man]

Thought I would give it a go as it sounded like a good idea-



I attached it to the auxiliary frame that came with the tank bag. It is powered off an SAE connector that is the pig-tail for the Battery Tender. Unplug the BT, plug in the volt meter.
Meter is a $16.00 basic unit from Amazon. It’s supposed to be waterproof.
I’ll see how it works out.
OM

 

[globalrider]

I met with my friend today who rides a Honda CBF 1000 and since he has had 2 stator failures so far, he wanted to install an on-board voltmeter. I should have taken a pic of it mounted on his motorcycle. His voltmeter mounts on the handlbar between the two handlebar clamps.

https://12vtechnology.com/products/motorcycle-handlebar-combo-voltmeter-usb-charger-and-on-off-switch-draws-no-power-csvu-r-b-smnt-sbpn-a60

He ordered it with the clamp...

 

[cabnfvr]

If anyone uses one, most (if not all) Escort radar detectors have a voltage display option.

 

[brownie0486]

My voltmeter reads 12.3-4 key on; 14.2-3 running; 10.3-11 cranking the motor.

I've seen 9.8 a few times while cranking. Battery replacement in a month or so when it goes in for service. Sits on a tender full time when it's home.

 

[globalrider]

I've seen 9.8 a few times while cranking.

How are you taking that measurement?

 

[brownie0486]

How are you taking that measurement?

On the volt meter plugged into the canbus socket on the dash of my 2011 rt

All measurements listed are off that device on the dash.

Is that somehow a problem?

 

[globalrider]

Is that somehow a problem?

If you are trying to measure the battery voltage while the engine is cranking, the voltage will fluctuate due to varying loads during a start.

You need either a scope or a quality meter with MAX and MIN holds.

If you want to test the battery which should be fully charged, use a load tester on it set to 1/2 the CCA of the battery spec. You'd like to see 9.5V minimum (temperature dependent) for a duration of 15 seconds.

If you looked after it, chances are you are replacing it long before its time. My 7 year old battery acts as if it is new.

 

[brownie0486]

If you are trying to measure the battery voltage while the engine is cranking, the voltage will fluctuate due to varying loads during a start.

You need either a scope or a quality meter with MAX and MIN holds.

If you want to test the battery which should be fully charged, use a load tester on it set to 1/2 the CCA of the battery spec. You'd like to see 9.5V minimum (temperature dependent) for a duration of 15 seconds.

If you looked after it, chances are you are replacing it long before its time. My 7 year old battery acts as if it is new.

Several have stated cranking should be about 11, below 10, replace battery. You're stating the volt meter isn't an accurate measure of volts?

Thanks

 

[globalrider]

You're stating the volt meter isn't an accurate measure of volts?

Nope, that is not what I stated. When the voltage is fluctuating during a start, taking a voltage reading with a plain DMM might not provide you with the value of interest.

Anyway, does it start easily or not? That is a better indication. I do not need to measure the voltage drop on my battery as it starts as easily now as it did when I picked it up when it was new 7 years ago. A simple audible test...no DMM needed.

 

[brownie0486]

Nope, that is not what I stated. When the voltage is fluctuating during a start, taking a voltage reading with a plain DMM might not provide you with the value of interest.

Anyway, does it start easily or not? That is a better indication. I do not need to measure the voltage drop on my battery as it starts as easily now as it did when I picked it up when it was new 7 years ago. A simple audible test...no DMM needed.

Seems to start fine, even when it's sat for 2 days like over the Xmas trip to Rocky Point this year. Usually on a tender or being ridden daily during trips.

Thanks for the reply sir

 

[Omega Man]

I think most are looking for a "good idea" on how their battery is performing. The digital voltage indicators show that. Even though I have a couple of these-

https://simpsonelectric.com/products/test-equipment/vom-multimeters/260-8-260-8p/

I am fine with a "basic" digital. Sure the starting sound/speed of turnover is a good indicator but 3 to four years is about all the grace I will give a power-sports battery.

I hear of long term success like a friend of mine, 13 years on a Yamaha ATV, but believe its an anomaly. I did suggest he have it bronzed when it finally did give up.

Probably among the least long term reliable are the batteries in lawn equipment.

Seven years reminds me of thin ice.

OM

 

[globalrider]

Seven years reminds me of thin ice.

OM

9 full years out of a conventional lead acid battery on my R100 GS and it never saw any charger/maintainer except during winter storage.

Cars, 14 and 16 years out of a conventional lead acid battery. Now these AGM batteries that I have in two vehicles are still in the "probationary" phase.

And none of them have left me stranded. Now the oilhead starter is another matter.

OM, you live in MA, not AZ where ultra-hot 100F temps kills batteries.

I wonder how many know what the mirror on an analogue meter is for.

 

[globalrider]

Usually on a tender...

The trouble with using a "battery maintainer" on a daily basis is it gives the owner of the vehicle a false sense of security with respect battery condition. Why, because on a battery that is normally weak due to old age, the charger/maintainer gives it that extra oooomph to get the motorcycle going. Then you are overnighting at a motel without the battery maintainer, and it won't start the following morning. Obviously battery capacity is way down and/or it is self-discharging far too quickly.

I'd use one if I was parked for more than a month. Disconnecting the charger/maintainer and after the surface charge bled off, I'd see 12.9V. Three weeks later, I'd see 12.8V. There was no point in keeping the charger/maintainer hooked up all the time.

 

[Omega Man]

I wonder how many know what the mirror on an analogue meter is for.

I generally don't get in that deep.

The "sweep" of the meter is so instantaneous it allows to look at voltage changes unlike the time I find it takes for a digital meter to "settle in".

I even have the custom Codura case!

OM

 

[globalrider]

I generally don't get in that deep.

The "sweep" of the meter is so instantaneous it allows to look at voltage changes unlike the time I find it takes for a digital meter to "settle in".

OM

The mirror? Think of it as the rear and front sights on a handgun. So that when you are looking at the needle and the reflection in the mirror, they line up and then you can look at the value.

And there is plenty of lag and oscillation in the needle as well for changes in reading.

 

[Omega Man]

The mirror? Think of it as the rear and front sights on a handgun. So that when you are looking at the needle and the reflection in the mirror, they line up and then you can look at the value.

And there is plenty of lag and oscillation in the needle as well for changes in reading.

I probably should have said I don’t need that functionality often. Sometimes it gets fussy with electronics repairs but very tough with SMT populated boards.
At least you can see the sweep meter move which allows the “next” step.
I usually get by.
OM

 

[rogerc60]

If your digital meter has a manual range function, you can get behavior similar to that sweeping analog needle by putting the digital meter on fixed range before starting your test. Some digital meters also have an analog-like bar graph readout below the numbers that simulates the analog needle. Very useful.

 

[brownie0486]

The trouble with using a "battery maintainer" on a daily basis is it gives the owner of the vehicle a false sense of security with respect battery condition. Why, because on a battery that is normally weak due to old age, the charger/maintainer gives it that extra oooomph to get the motorcycle going. Then you are overnighting at a motel without the battery maintainer, and it won't start the following morning. Obviously battery capacity is way down and/or it is self-discharging far too quickly.

I'd use one if I was parked for more than a month. Disconnecting the charger/maintainer and after the surface charge bled off, I'd see 12.9V. Three weeks later, I'd see 12.8V. There was no point in keeping the charger/maintainer hooked up all the time.

So I took it off the tender 5 hours ago. Turning the key on the meter read 12.5, turned the key off went to 12.6. What's that telling you where yours reads .3-.4 volts higher?

 

[globalrider]

So I took it off the tender 5 hours ago. Turning the key on the meter read 12.5, turned the key off went to 12.6. What's that telling you where yours reads .3-.4 volts higher?

Turning the key to ON puts a load on the battery and a drop of 0.1V is absolutely nothing to worry about.

Depends on your battery type? Do you have a GEL or AGM battery? Or is it just a flooded lead acid battery. 12.6V to 12.65V open circuit (no load) is normal for a flooded lead acid battery.