Fluctuating Datal Voltmeter

[1FJR]

First some basic info on the bike. It is a 2004 with 38000 miles. I have added power strips under the front. I only run a XM roady 2, Autocom, Hella FF50 and Heated vest. I returned 3 weeks ago from a trip to NY with out any problems. I have checked all the connections and everything seems to be tight and secure.

Here is what is happening. I rode from Granby to the front range. When I started this morning it was approximately 60 degrees. I did not use the vest. When I had gotten to Ft. Collins it was 86 degrees. I observed that the Volt meter was reading any were from 13.4 to 13.9 when I was in the heat. It mostly stayed around 13.6, but would drop to 13.5 when the turn signals were on. Also I turned off my XM at one point and the volt reading went from 13.7 to 14.0.

As I got back to Grand County and cooler temperatures (only 2 bars on the bike) the reading was now 14.0.

 

[Last Chance]

If I recall my "radio theory" correctly resistance increases with temperature. Seems that increasing the temperature and the load imposed on the electrical system might well cause the voltage to drop. If it doesn't drop excessively that might be normal. However, excessive voltage drop might also indicate a weak battery or problem with the charging system. My bet is that the battery is getting a little old. The FJR could really use a bigger alternator, also. It doesn't take much to drain the battery either!!! BTDT within 20 minutes!!

LC

 

[1FJR]

If I recall my "radio theory" correctly resistance increases with temperature. Seems that increasing the temperature and the load imposed on the electrical system might well cause the voltage to drop. If it doesn't drop excessively that might be normal. However, excessive voltage drop might also indicate a weak battery or problem with the charging system. My bet is that the battery is getting a little old. The FJR could really use a bigger alternator, also. It doesn't take much to drain the battery either!!! BTDT within 20 minutes!!
LC

I should add that the battery was replaced at the beging of the year. I rode through some tempatures that reached into the high 90's on my trip three weeks ago and the drop was only down to 13.9. I have planed on replacing the stator this winter, just trying to make sure that there is not some thing else that I should be looking for. Thanks for the help.

 

[Rogue]

My guess would be the Voltage Regulator.

 

[1FJR]

My guess would be the Voltage Regulator.

As the weather has gone bad today, thought that I might try to check some more areas. Is there a way to check the voltage regulator?

 

[smitty141]

I just sent one back to Datel on sat. The problem I have was a meter problem. It started out fine (13.9volts) but after a few hours riding it was reading a neg. -70.0 volts. I gave them a call and was told to send it back for a new one... Great customer service... Smitty :yahoo:

 

[Rogue]

My guess would be the Voltage Regulator.

As the weather has gone bad today, thought that I might try to check some more areas. Is there a way to check the voltage regulator?

You would have to test it cold and test it hot (when you have the voltage problem). A PITA! If you have access to a good multi meter should verify the Datel is correct, as Smitty just pointed out it could be the Datel.

 

[1FJR]

I decided to check the reading of the Datal against my multi-meter. Here is list of what I saw after the bike got hot. The only thing that I did notice that was odd was at times with my FF50's on, the Datal would be steady, while the multi-meter would slowly be dropping.

Engine Hot 3/4 bars

1st line-Datal Reading

2nd line-Tester Reading

Idle

14.1/14.0

14.08/14.10

Idle w/fan

14.0/13.3

14.0/13.75

FF50

13.3/13.2

13.70

FF50 w/fan

11.9/12.0/12.1

12.50/12.70/12.62

Just Battery

13.79

Ignition on

12.6

13.0 dropping to 12.66

So my question is if the Multi-tester readings are in the range that they should be. I have not been able to find any reference to what others have seen.

Right now it looks like it may be the Datal. I may try and see how much the Voltage regulator is and if it might be covered under the extended warranty. I am planning on updating the stator this winter.

 

[smthng]

I've got a Datel (double digit) on my '05 and your numbers seem pretty close to mine. I've haven't done a "consistent" test, but here are my general observations on what the Datel kicks out to me.

Idle with nothing else sucking juice - 13.9-14.1

Idle with fan - 13.2-13.7

Idle with FF50s (on a relay) - 13.2-13.5*

FF50s with fan - 11.7-12.6

Ignition on, bike not running - 13.8, but drops fairly quickly

Normal running voltage at speed with nothing sucking juice - 14.2-14.5 - VERY dependent on temp and how long the bike has been running

*One oddity I've seen is when I turn on the FF50s, the voltage drops down to 13.2'ish and then slowly climbs back up to 13.5'ish. This is the only accessory that causes this. I'm guessing that the relay (Bosch) takes a "surge" of power to make the initial connection, but consumes very little power once it is on. So, it does a quick battery drain, but then backs off once the connection is made... that's the only explanation I can think of that explains climbing voltage.

As for your other accessories... I have no idea what the XM radio draws. If it helps, here's some additional stuff I run at times on mine and what I notice about it's affect on the Datel:

Garmin 2610 - less than 0.1 effect on Datel

Autocom Pro Sport - No noticable effect

Cell phone charger - about 0.2 effect

Cheesy walmart 35watt fog lights - about 0.5 effect - much worse if voltage is already being drained by something else big (like fans)

Yamaha heated grips - about 0.2 effect - surprised me, I was expecting a huge drop. The low voltage cutoff is a nice feature.

Heated gear - about 0.9 effect - enough to make me turn off additional lights if I really need to run the heated stuff at full burn any time I'm under 3000 RPM.

I know that's not exactly what you were hunting for, but it might help. Personally, I think all your Datel numbers are pretty much in line with mine and that you don't have anything to really worry about. If I were on your bike, I might turn off either the lights or the XM when the fan kicks on at a stop light, but otherwise I think you're right in the ballpark of where you should be and it looks like the Datel is working fine.

As an added note, I don't trust the voltage at low RPMs. At lower RPMs, I know the bike isn't generating enough juice and there are other weird things going on... fans, brake lights, turn signals, surging, temperature build up, back-off flashers, etc. I generally pay much more attention to the Datel when I'm at speed. That's when I decide if I can turn on more electrical crap. When stopped, I just turn stuff off until it stops dropping voltage or give it a tiny bit of gas to bring the idle up if I'm just going to be stopped for 20 seconds or so. Eventually I'll get around to installing my new stator so I can just power everything and quit worrying about it.

 

[Ratman]

Why do you care what the voltage is doing? I would think you would like to know what the amps are doing. Is it pos or neg or charging or not charging? The voltage shouldn't be such a big deal as long as the Datel is pos you should be ok.

Just an opinion.

 

[Ignacio]

Why do you care what the voltage is doing? I would think you would like to know what the amps are doing.

My understanding is ammeters are more difficult to install and utilize....and not nearly as well documented on the FJR. You wanna be a tester and give us a write-up on how to install and use one?

 

[Ratman]

I have one installed; it's a shunt that bolts right on the pos terminal. Easy as connecting two bolts.

I’ve had it on for two years now; it works ok but very sensitive to the regulators output.

With motor off and lights on it will be about neg 18 amps. It’s a test I do just see if ever thing is charging right. Running down the road it bounces around -5 to a + 5, unless I’ve run it down by leaving my radios amp on and walking away.