battery issue...

[mikedastonfj1100]

This is someting I spotted was 2 days after a good day of riding the battery would show 70-76% on my battery charger... The battery charges up to 100 % every time.... It does not ever drop below 70%.... Is this normal?

[rktmanfj]

What does it measure with a VOM after riding?  After charging?

How old is the battery?

Conventional, AGM, or Lithium?

[movenon]

After your battery is fully charged, disconnect a terminal and let it rest over night,  in the morning take a voltage reading and report back what the voltage is 
George

[mikedastonfj1100]

12.4 volts is what the charger said this morning.... I put it on a trickle charger last night...

[mikedastonfj1100]

Its a WalMart ever start battery... That's all I know... Looked all over the battery for anything else... Its probably the typical conventional type...

[Fj.itis]

Attach the volt meter whilst you are trying to start it, make sure it starts first. If the voltage drops below about 9-10 volts before it fires, its an indicator that its getting old. This will test it under load and give you a rough idea how you battery is performing.

[movenon]

Attach the volt meter whilst you are trying to start it, make sure it starts first. If the voltage drops below about 9-10 volts before it fires, its an indicator that its getting old. This will test it under load and give you a rough idea how you battery is performing.

12.4 volts indicates to me it is about 75% good. But do a load test if you can. Also with the negative hooked check your current draw with the ignition off (if you have a 88-93 you will have a small draw due to the clock).  

Checking your charging voltage while riding is a good idea. The FJ (and others with the Denso alt) can over charge (in excess of 15 volts) due to a failing voltage regulator.  There are work arounds for this.  The over charging will reduce the battery life.

Here is some resting voltage parameters. Technically they will vary a bit with the type of battery.
State of Charge   Specific Gravity   Voltage
          
100%                 1.265            12.7    
75%                  1.225            12.4    
50%                    1.190            12.2    
25%                    1.155            12.0    
Discharged            1.120            11.9    

I have 1990, been off for 36 hours and my voltage reading is 12.3. The battery is 2 years old.  And its about where I would expect it to be. I get a higher than normal charging voltage for a short while then it will settle down to a normal charge rate.

Last year I installed a 10.00 e bay digital voltmeter and I like the it a lot. Hope the info helped.  Are you charging it up because of a no start condition ?  My experience with motorcycle battery's is they last for 2-3 years.  But I am in a cooler area.
George

[mikedastonfj1100]

For some odd reason I can't find the receipt for a date as to when I bought it, but as far as I know its 2 1/2 to 3 years old...about 3 months ago I got around to start putting a fresh charge on it at least 2-3 times a week.... Just started seeing this issue about a week ago....

[mikedastonfj1100]

I left the battery off the charger last night all night an checked it this morning and it said 76% at 12.5 volts.... Put it on a slow charge and went to work... When I got home it said 100% at 13.2 volts....

[movenon]

Best guess is your battery is around 50 % gone.  The battery will probably keep going for a while. You have to evaluate how much reliability you want.  But I would start shopping for a battery or doing some reading on a new one.  I have a hard time making motorcycle batteries last more than 2 to 3 years and still be reliable.  If you want to keep using that battery I would buy or make a set of jumper cables out of some 10 Ga wire about 6' long and coil it up in the tail section.
George

[red]

This is someting I spotted was 2 days after a good day of riding the battery would show 70-76% on my battery charger... The battery charges up to 100 % every time.... It does not ever drop below 70%.... Is this normal?

Mike,

Normal for an older battery, sure.  Take a voltage reading with nothing ON, key out.  Then take a reading at 3000 RPM.  If the voltage is not higher (and somewhere over 12.5V) when running, the bike is not charging the battery well enough.  If the running voltage is good, then the battery is just old and weak.  A really bad battery can drag down the charging voltage, though, so do not be too quick to blame the bike, if the charging voltage is low.  I would doubt that your battery is bad enough to drag down the charging voltage, because the charger that you have can bring the battery back up to 100%.

Batteries fail by age, because the plates become encrusted with sulfate deposits, over time.  The right "Battery MINDer" type of battery tender can de-sulfate the plates in maybe a week or two, and keep them working well.  Run-of-the-mill battery chargers can not do that.  I use this little guy, which charges at two amps (I already have a serious battery charger) but this company also has "battery MINDers" that can charge at heavier outputs:

http://batteryminders.com/details.php?prod=2012

It works on a variety of lead-acid batteries, so it will benefit your car battery, as much as your bike battery.  If somebody has one that you can borrow there, it may fix your old battery, but it will take a while.

My advice is, quick-n-dirty: See if the charging voltage on the bike is good, at 3000 RPM.  If so, get a new battery for the bike.  Buy the Battery MINDer later, when finances permit, to keep that new battery in good condition, and to restore your other old batteries.

Cheers,
Red

[andyb]

Its a WalMart ever start battery... That's all I know... Looked all over the battery for anything else... Its probably the typical conventional type...

Throw it away.

Been there, done that, etc.  Those are CRAP.  They're fine if you're in BFE and need something to get you home, and they are worthless in every other sense of the word otherwise.  A decent AGM battery will last several years and the cost per year over the lifetime is nothing by comparison.


<Edit>

Don't throw it away away, you can get $9 or something for a core if you return it to walmart.  You know what I mean though.

[mikedastonfj1100]

  don't think I'm gonna throw it out just yet... It has been a thought though.... I've got a small portable charger that I can stuff in the tail and use the night before I take her out for a ride... Does anyone know of a good place for to buy lithium batteries?? Also any good website for parts, besides bikebandit.com?? I have noticed bike bandit has been charging too much for simple low cost parts...

[movenon]

Here is an interesting video. His FJ will not run and fuel all over the ground but the interesting part is his battery   Not bad for turning over a .65 kw starter (50 amp).

http://www.youtube.com/watch?v=5ZT_qK91zxU
George

[mikedastonfj1100]

That vid was interesting.... It acted like it wanted to stay running... That bat looks like it would have come out of an r/c car... He should have used 2 of those batteries... It might have worked a little better:)