Datel Voltmeter Question

I installed a Datel Voltmeter this past weekend, and overall I think the install turned out pretty well.



The question I have, is what kind of readings should I be getting on the Datel? I tied the Datel into the headlight power, so it should be getting plenty of power, but as you can see in the picture it will read up to 13.3 just idling, and I have yet to see it go above 13.5 at anytime, regardless of RPM's.

I found a thread that said I should be getting readings above 13.7 if everything is working correctly, and there is now extra draw on the electrical system. The only thing I am currently running is a ZUMO GPS, and some aftermarket bulbs in the head lights. the battery was just replaced on the bike a few weeks ago, and I usually put it on a Battery Tender once a week. I almost never ride less than 35 miles at a time, and it is all highway speeds.

Any thoughts?

See, there ya go, you had no electrical problems until you looked. Now you are phucked :lol: [/Friday]

You need to look at your battery voltage with a good DMM. I'm betting that the voltage is around 14.0 volts, probably a bit less. If you want to go through the plastic pain to check the voltage at the regulator, I'm betting the voltage will be right around 14.3 to 14.5 volts.

Be sure your battery is screwed up, err, the terminals are securely fastened.

Report back, next steps depend on the test results.

Very clean install, by the way.

Thanks GunMD. I used a dremel, with a diamond cutting wheel I had purchased for another task. I didn't even take the plastic off of the bike to do the install, other than the panel above the battery itself. The dremel cut through the plastic like butter. A little work with a fine metal file, and it was so perfect it started to scrape the sticker off of the side of the Datel. I had to make it just a little bigger after that, but I was still very happy with the results.

Now if I could just get it to give me a true reading, I would be all set.

nice install, very clean!

As a previous poster said the only place to check your battery voltage is at the battery. The wiring (including connectors) from the battery and the amount of current going through them will result in some voltage drop. You picked the headlight circuit to monitor which has a pretty significant draw. Having a couple of .1's volt drop delivered to the lights would seem pretty normal to me.

As an example if your lights draw 5 amps and your lighting circuit has a resistance of .05 ohms you would see a drop of .25 volts from the battery to the lights.

ymmv

btw if you want a 'true' battery voltage reading then attach the leads right to the battery

The drawback to the direct battery connection is the "always on" mode. My solution was to use a switch...

Write-up can be seen HERE.

Alternately, work up a switched power block and run the datel to that.

https://www.fjr-tips.org/mods/pdb/pdb.html

TriggerT said:

Now if I could just get it to give me a true reading, I would be all set.

Click to expand...

I believe it is giving you a real reading. I think it is low because the voltage at your battery is low. In addition you are reading off of a switched ignition circuit which is usually ~0.5 volts lower than battery voltage.

GunMD said:

The drawback to the direct battery connection is the "always on" mode. My solution was to use a switch...
Write-up can be seen HERE.

Click to expand...

I am also monitoring a switched power source, but as someone else pointed out in an earlier thread, the full power draw of a Datel voltmeter is 2.5ma. That's pretty low. You could just leave it on all the time.

Trigger - I mounted mine on the right side near the battery (05). I ran it thru a BlueSea I had installed under the rear seat - the BlueSea is switched. On start-up I always read 14.2. Once she warms up, and depending on the outside temp, it'll run from 13.9 to 14 or 14.1 (no load).

GunMD said:

The drawback to the direct battery connection is the "always on" mode. My solution was to use a switch...
Write-up can be seen HERE.

Click to expand...

What would that type of switch be called (the on-off-momentary)?

Thanks for all the replies! I think I will run it directly to the battery for one of my up coming rides, and see what it reads. From there i will have to decide how, or if I want to change the wiring. I think directly to the battery with a switch might be the way to go for me.

LDRydr said:

GunMD said:

The drawback to the direct battery connection is the "always on" mode. My solution was to use a switch...
Write-up can be seen HERE.

Click to expand...

What would that type of switch be called (the on-off-momentary)?

Click to expand...

Any single pole single throw switch would be adequate. This is a pretty low voltage low amperage application. The most important thing would be finding one that was weather resistant.

One other point not made. Even though the readings you are getting from the headlight wiring is different than those when you read directly from the battery, they are just as useful. Once you know what a "normal" voltage reading is at that point, when you have charging and/or battery problems the voltage will be different (lower or higher) than normal and you will know there is something going on. Knowing the precise voltage at the battery is really not that important.

This is the BlueSea switch that I used (PN 4153).



And this is the BlueSea toggle switch boot that I used (PN 4138). I can't recall where I purchased them but I can find it when I get home and post up here (if anyone needs that info).



EDIT:

I purchased those switches from Fisheries Supply.

Link to switch. (The picture looks different, but I got the right switch)

Link to boot.

"the full power draw of a Datel voltmeter is 2.5ma. That's pretty low. You could just leave it on all the time."

Hmmm,

12AH battery capacity with .0025A draw after 3 months it might get a little dicey for starting the bike.

Zorlac said:

...after 3 months it might get a little dicey for starting the bike.

Click to expand...

Holy crap! Three months??

My bike has rarely seen more than three days. Ahhh...I love the desert.

Perfect, that's what I was looking for. Thanks for the details.

Zorlac said:

"the full power draw of a Datel voltmeter is 2.5ma. That's pretty low. You could just leave it on all the time."
Hmmm,

12AH battery capacity with .0025A draw after 3 months it might get a little dicey for starting the bike.

Click to expand...

Haha. Yeah, if I don't charge my battery for 3 months it would be dicey starting it with nothing connected.

Fred W said:

LDRydr said:

GunMD said:

The drawback to the direct battery connection is the "always on" mode. My solution was to use a switch...
Write-up can be seen HERE.

Click to expand...

What would that type of switch be called (the on-off-momentary)?

Click to expand...

Any single pole single throw switch would be adequate. This is a pretty low voltage low amperage application. The most important thing would be finding one that was weather resistant.

One other point not made. Even though the readings you are getting from the headlight wiring is different than those when you read directly from the battery, they are just as useful. Once you know what a "normal" voltage reading is at that point, when you have charging and/or battery problems the voltage will be different (lower or higher) than normal and you will know there is something going on. Knowing the precise voltage at the battery is really not that important.

Click to expand...

Fred is right on here. IF you leave the connection on the headlight circuit you will get the info you need - ie when there is a change in 'normal' voltage being delivered there.

BUT why make this more complicated than it is? If you just tap into a switched circuit that is not drawing a lot of current that would solve your problem. A switch on a voltmeter doesn't make much sense.

btw I am really a skeptic when it comes to voltmeters (gee, did a EE just say that?). After the first few rides my guess is that most people don't ever look at the readout - until somehing bad happens & then its too late. But the meter will tell you the battery is dead at that point. An idiot light would be more useful, but granted, not as pretty.

Its still a nice looking install