Batteries Dying???

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Nov 9, 2023 | 08:45 AM

#31

98hotrodfatboy

Seasoned HDF Member

Joined: Mar 2010

Posts: 21,005

Likes: 7,540

From: Poolville

I had a 79 650 xs special that needed a new battery every year, sometimes wouldn't even get a year or of the battery .. replaced the stator and rotor and issues went away..

Nov 9, 2023 | 05:46 PM

#32

Dano523

HDF Community Team

Joined: Jan 2020

Posts: 1,434

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From: Colorado

Just a FYI, but when checking a voltage regulator, after your done with DC meter settings to make sure you do have climbing voltage as the rpms comes up but do not climb higher than 14.2V DC, Do the test again, but this time set the meter to A/C, to check for A/C leakage past the voltage regulator as well.

Hence stater puts out A/C, and voltage regulator is to convert that to DC via bride rectifier, but if you have A/C leakage past the voltage regulator to the battery (one of the diodes in the bride rectifier blown wide open), this is going to do the battery in short order as well.

Nov 9, 2023 | 09:33 PM

#33

Tommy C

Seasoned HDF Member

Joined: Oct 2015

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From: Pine Flat Dam/South Bay Area, CA

Quote:

Originally Posted by Dano523

That's a good diagram of a full wave bridge rectifier, except there should be no positive or negative polarity on the input leads because the current entering the rectifier is A/C.

Last edited by Tommy C; Nov 9, 2023 at 09:35 PM.

Nov 10, 2023 | 07:35 AM

#34

Racepres

Seasoned HDF Member

Joined: Jul 2014

Posts: 8,564

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From: Cental, MI

Quote:

Originally Posted by Tommy C

That's a good diagram of a full wave bridge rectifier, except there should be no positive or negative polarity on the input leads because the current entering the rectifier is A/C.

No...It is Drawn correctly.. However...No Juice gettin thru anything "blown wide open"...

Edit; I doubt that anyone will find a Rectifyer that has No AC riding on the output!!! All Rectifyers produce "pulsing" DC... the trick is to Identify Too Much AC component!!! Over a Volt or (maybe even Two, on cheap Chiwanese regulator) I would Consider Excessive!!

Edit; I am leaning toward the Bold type to Be Wrong...tho some AC component is always on rectified AC,,,even 1 Volt out of 12 is very excessive..I was considering electronic Power supplys of 30VDC plus...Apologies.. Check yer AC component in Millivolts please!!!

Last edited by Racepres; Nov 10, 2023 at 07:59 AM.

Nov 10, 2023 | 08:37 AM

#35

t150vej

HDF Community Team

Joined: Dec 2005

Posts: 5,374

Likes: 2,570

From: NC USA

Quote:

Originally Posted by kino44

.............if I ride the bike just normally 65-75ish she seems fine but some days I tend to push her over a bit 85-100 if I do this to many times the damn battery just dies??? ..............
Thanks

Sounds like you've covered all the bases several times very well, but I'd like a bit more detail on the above statement. Does it die while riding or after a period of time (days or weeks) or just dead the next day after high speed runs?

FLH/T had the battery mounted on the right crash guard from '79 thru '92. There is supposed to be a heavy rubber tray the battery sits in and that hold down strap needs to be replaced every 3-5 years to keep vibes in check.

Though it's been done, you will hate yourself for moving to an under seat battery on that bike.

Nov 17, 2023 | 04:42 PM

#36

Rufus13

Road Captain

Joined: Jul 2023

Posts: 509

Likes: 390

From: So Western Ohio

Leave the tender on all winter? hmm. I always did. My battery seems weaker. So..
Today I ran a simple test to learn about this Deltran Battery Tender Junior. It was bought in 2014. The bike was ridden yesterday.
The battery read 12.75 volts today.
You have to give a freshly charged battery a little time to burn off its 'surface charge.' It had 24 hours to settle before I checked it.

Then I hooked up the tender. While the red light was on its output slowly ramped up to 14.5V.
The green light began to blink (trickle charging) but it was holding at 14.46V. It has current control and claims a max of 750MA. It was hopefully delivering less than 750MA while blinking green. Anyway, it stopped blinking after 15 minutes or so and went steady green.
At this point it slowly ramped down to about 13.2V
I gave it two hours to lose any excess surface charge while still maintaining, then checked again.
It was still sitting at 13.2V. I disconnected the tender, tapped the mileage display button for a minute or two to lose the surface charge, and the battery had come down to 12.8V. The results are inconclusive, as far as over charging the AGM battery. It does apply a slightly higher voltage than a resting 12V m/c battery, so some current is flowing.
The new plan is to plug it in once a week and unplug it when the green light goes steady. I doubt that much charging is going to cook out very much water.
Hope this info helps guys understand what these things are doing out there alone in the garage all winter.

Nov 26, 2023 | 08:32 AM

#37

tar_snake

Stellar HDF Member

Joined: Nov 2010

Posts: 3,108

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From: Directly above the center of the Earth

Quote:

Originally Posted by Rufus13

Does that help any with your compression problem?

Apr 29, 2024 | 11:39 AM

#38

ucbruce

Road Captain

Joined: Apr 2009

Posts: 510

Likes: 174

From: Ball Ground, Ga.

Quote:

Originally Posted by brakeless

I get about 7 years on my batteries. I have tenders on two bikes. Sometimes one will sit for quite a while because the old lady rides it mostly. Get yourself a tender and make double sure every connection and cable is perfect. I also switched to gold cables and never looked back.

I just replaced the battery in my 2013 FLHTK, and I got about 6 years out of it. Keep it on a tender...