Battery charging voltage

[SigepKat]

I suspect I could find this w/search, but I didn't have any luck so here it goes...I recently added a USB outlet to my handlebars and, since it was only a couple bucks more, got one w/a volt meter. It's been on the bike for a few weeks now and I'm concerned about the battery now. It starts and runs fine, even after sitting for a week, but the volt meter shows about 11.5v at idle at 13ish when cruising at highway speeds. On my truck, I get concerned if things drop below 13 at idle, I'd be poking at the alternator if I saw it regularly at 11v. Do I have a problem coming up w/the charging system on the bike? For reference, it's an 09 w/86k miles on it. During the summer, the charging system isn't taxed to hard by accessories, but when it starts getting cold, I've got electric gear that I run...Any help is appreciated.

Chris

 

[SigepKat]

And of course, after posting this, I come across this -

With a good charging system, and a healthy, properly charged battery I would offer these guidelines for sustained voltages:

≤12.8 volts at the battery terminals – the charging system is over taxed, the battery is being discharged, and the stator is in danger of being permanently damaged.

12.8 to 13.2 volts – entering the danger zone, the battery is no longer being trickle charged and the stator is being taxed to the limits.

13.2 – 13.7 volts – undesirable but sustainable, the stator is taxed but the battery is being charged.

13.7 to 14.5 volts – schweet

12.7-12.8 volts – good battery voltage when it is fully charged and disconnected from the motorcycle; measured at 70°F

Sounds like my charging system may be on the way out...

 

[bseelbach]

A couple things to consider:

-Depending on where you tapped into power, you could have some voltage drop from the OEM wires. It doesn't seem to be a huge issue with the FJR but on my Suzuki Cruiser, it was not uncommon to have almost 1V drop if you tapped into a low gauge OEM wire.

-The all in one meter may be junk. I would suggest you check voltage at the battery terminal with a good quality meter.

-Bikes take a bit to replenish the power needed when starting. General rule of thumb is 10 min or so. If you continuously take short 5 min runs, you will eventually wear out the battery as each start is taking more power than the 5 min ride can generate. This applies mostly to the resting voltage.

I have had good luck with these volt meters. I have them on all of my bikes powered via switched fuse block and double sided taped to the side of the frame just rearward of the steering stem. After replacing a stator on the side of the road in the middle of a road trip on my cruiser, I like to get a visual of how the charging system is doing.

https://www.amazon.com/dp/B00JOB78Z6/ref=sxts_bia_sr_1?pf_rd_m=ATVPDKIKX0DER&pf_rd_p=3182441022&pd_rd_wg=jRdYy&pf_rd_r=MAECVF3B4G5RP5A3V9B6&pf_rd_s=desktop-sx-top-slot&pf_rd_t=301&pd_rd_i=B00JOB793W&pd_rd_w=jpvJQ&pf_rd_i=0.28+volt+meter&pd_rd_r=R2ZX0VY5K87Z3PAAAB41&ie=UTF8&qid=1504794590&sr=1

Or you can buy from Aerostich for a few bucks more....

https://www.aerostich.com/compact-digital-voltmeter.html

EDIT:

You may need to go slightly above idle to get a proper running voltage. Depending on where your idle is set, the bike may not make alot of power. Try taking a running reading at 2K RPM. The voltage values you referenced above are correct for the most part. 14.5V while running is a bit high. Most upper limits I have seen reverence 14.1-14.2V as a healthy system.

 

[graler]

I just checked my datel - it is connected through a switched circuit on my eastern beaver fuzeblock. At idle (sitting on the center stand in my garage) my voltage is showing 13.25.

Joe

 

[SigepKat]

Just checked it w/a multimeter and the volt meter on the bike is pretty accurate, w/in .1 of the multimeter. At about 5k RPM I was able to get it up to 13.5 volts (on both) but that's about as high as I could get w/out wringing the motor out (which didn't seem like a good plan sitting in the shop.)

CM

 

[RossKean]

Here's a thread for your reading pleasure...

https://www.fjrforum.com/forum//index.php/topic/146331-krzy8-gen2-charging-circuit/?hl=harness

 

[Harald]

Did you check the charging voltage at the battery? If not, check there because there could be voltage drop in the line to your installed volt meter.

Probably your issue is in the link that RossKean posted. My high mileage 07 also had deteriorating voltage at the battery that became a problem in the winter with heated gear running. I patched in the harness listed in the other thread and instantly went to 14.2 volts at the battery as read on my datel meter.

 

[SigepKat]

I checked the straight from the battery w/the multimeter.

Does this mean I may need just the $50 patch kit or something additional?

CM

 

[Harald]

The problem is that the various connections and/or undersized wiring from the Regulator/Rectifier to the battery causes excessive voltage drop. The new harness from roadstercycle.com replaces all that with a solid run of wire and fixes the problem. You don't even need to remove the old wiring - just disconnect both ends of the original wiring and then run the new harness. Completely fixed the problem on my bike (and Dcarvers bike in the link above).

 

[SigepKat]

Hey all, I've got an 09 w/about 95k miles on it. I added a voltmeter not long ago and it's readings are a little concerning. W/the only additional load being some LED spots I use as running lights, it shows around 13.1 volts, when I add my electric gear (jacket liner, gloves, socks) at highway speeds, it'll show 12.3 or less. Obviously this has me a little concerned. I've had the new harness from RoadsterCycle.com mentioned, but it sounds like that'll only give me .5v increase. I'd like to get back up to the 14v range, ideally w/the gear running, but definitely w/out. What needs to be replaced/cleaned/tested/etc. to fix this?

CM

 

[Ignacio]

Many variables you don't include:

Exactly how did you wire the voltmeter wired? if not directly across the battery terminals--then you can suffer varying amounts of voltage drop. What happens when you put a multimeter across the terminals while it's reading 13.1? If the multi meter shows 13.5...then your voltmeter is off probably 0.4 volts. Also, remember that voltmeters do NOT measure draw. They're more an indicator when you're reaching alternator capacity. To truly measure draw you'd need an ameter.

Also, I'm not sure you'll ever get to 14 volts unless you change the voltage regulator. Most I've ever seen on an unmolested FJR is 13.9 volts I believe.

Finally, your LEDs and electric gear could add up to where you're reaching the alternator limits, but probably not. What specific draw do all those add up to? Each of their documentation should have specifications published. If it's more than 550-600 watts then you're near the likely Gen 2 alternator capacity.

Finally, I saw it after re-reading after the thread was merged and you said originally you added a USB, but didn't include it in your post today. Have you added anything else to the system? I guess I'd wonder and start removing things to see if you didn't wire something incorrectly and having an overdraw. What does it show with NO non-stock power draws? If closer to 14 then I'd add things back one-by-one and see if something drops the voltage more than it should.

 

[Ignacio]

Oh. I see you're going a bit thread-creation happy and already have a thread on this topic. Merging the threads and redacting some of my previous to keep the prior context.

Let's not keep reinventing the wheel please.

Thanks.

The Management

 

[Panman]

Like Harald and Carver, the roadstercycle harness took care of mine.

 

[mcatrophy]

...Also, I'm not sure you'll ever get to 14 volts unless you change the voltage regulator. Most I've ever seen on an unmolested FJR is 13.9 volts I believe.

....

Very surprised you say this, all of my FJRs ('06, '10, '14) have always delivered 14.2 volts at the battery under normal running conditions.

 

[flars]

I would pull the connector from the r/r and clean it. Then put dielectric grease on it. Sometimes it is just a bad connection at the r/r.