Battery Water.

 

'83 Honda VT500C Shadow.

IN hot weather, the battery goes dry in about 500 miles.
To put in water, I have to take off the seat, remove the battery,
fill it, reverse the process.  PITA.

It's my garage sale bike, so it does sit idling a lot while
I'm browsing.  The battery does get a workout.

Anything I can do to reduce the water loss or make it easier to fill?
Clever fill gadget?  Getting water to it ain't hard.  It's telling
when to stop adding water that's hard.

Regulator is at 14.39V.   Well within
the 15V max stated in the manual.
I'd crank it down a little if I had the option.

Ideas?
Thanks, mike

 

mike wrote:

There's absolutely no reason to leave your bike running while
you spend time at garage sales.  But that is irrelevant to
the problem you describe, other than it may expose your battery
to unnecessary amounts of heat.


You're trying to fix the wrong problem.


The battery is being overcharged.  Either the regulator is
defective or the sense line (common on Hondas) is sensing
the wrong voltage, causing the regulator to set the output
voltage of the alternator too high.  Fix the connection
problem(s) or replace the regulator.  Simply replacing the
regulator won't fix the problem if it's a connection issue.

I've seen this exact problem on at least two early 80s
Hondas and fixed them both the same way.  The problem is that
the Kelvin sense wire goes through the ignition switch, which
has a fair amount of voltage drop through multiple connections
on an older bike with oxidized connections.  So the regulator sense
line is seeing about 1V less than what the battery sees.  The
fix is to either clean and/or replace all the tired connections
or re-route the sense line directly to the battery.  If you
choose the latter option you need to ensure the sense line
doesn't draw excess current with the bike not running or it
can drain the battery quickly.  In both cases I verified this
with a sensitive milliammeter before committing to the fix.

 

Mark Olson wrote:

Sounds like you haven't done the math.
Start a bike 50 times a day and something that was designed to
last for many years doesn't last nearly that long.


  But that is irrelevant to

Good call.
Rerouting the sense line did drop the voltage.
Should know in a week if it fixes it.
All I gotta do is remember to charge it a few times
over the winter.

My jaw is getting tired from all the bubble gum I'm
chewing to keep this thing patched up.
If I could find a 500cc water-cooled, shaft-drive
bike, I'd buy a new one.  they don't make 'em
like they used to.

thanks, mike







The problem is that

 

mike wrote:

400 miles later and the battery is still full of water.
Rerouting the sense line seems to have fixed it.
Thanks for the suggestion.
mike

 



Beers all round on Mike, then.


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