battery health

[Lawrence]

My 1985 K100RS has a flooded cell battery.  I cannot find any indication of when it was purchased.  The bike never fails to start promptly.  I use a Ctec charger periodically to keep it charged.  After sitting idle a couple or three weeks, the charger takes about 12-18 hours to bring the battery voltage up to the point the green light of the charge lights. What, if anything, does this say about the state of the battery?  I don't have a hydrometer so the charger is the only thing I've used to evaluate the state of the battery.
Now, I'm not normally given to excessive worrying, but in roughly one month I'll begin our Grand Southwest Tour which may entail riding perhaps 2 k miles.  I don't want any surprises on the road.... :riding:

[TimTyler]

Seems like $110 for a new Odyssey battery is the most reliable solution. Batteries don't last forever.

[JamesInCA]

If you're going to be out on lonely desert highways, you might want a battery of known age and performance.

Or, you could maybe spend $3 on a hydrometer.

[Lawrence]

I've never owned a hydrometer.  Just exactly what do they tell you? I've bought one  because I'd assumed if a battery had a dead cell, for instance, it would show up on a voltmeter.
 

[robleyd]

If you buy a lead acid battery hydrometer:

http://en.wikipedia.org/wiki/Hydrometer#Battery_hydrometer

The state of charge of a lead-acid battery can be estimated from the density of the sulfuric acid solution used as electrolyte. A hydrometer calibrated to read specific gravity relative to water at 60 degrees Fahrenheit is a standard tool for servicing automobile batteries. Tables are used to correct the reading to the standard temperature

And much more detail at http://arconequipment.com/article_0995.html
 

[cheetah]

I have a Batteryminder on mine whenever it's in the garage.  It fully charges the battery the desulfates it.  It will charge and recondition any battery type; AGM, wet cell, ect...

My battery is pushing nine years old and sat dead, like flat zero, for seven of those years.  That Batteryminder brought mine back to life, if you will.

http://www.amazon.com/BatteryMINDer-Model-12117-Maintainer-Desulfator/dp/B000P23HZS/ref=sr_1_1?ie=UTF8&qid=1367813248&sr=8-1&keywords=batteryminder

[cheetah]

And while I am thinking about it, it you check the battery acid level and find it's low, you should add water to it, but only distilled water.

The minerals in regular water (tap, bottled, ect...) have minerals and metals that will attach themselves to the lead plates.  That will cause the battery capacity and life to be reduced dramatically.

[JamesInCA]

I've never owned a hydrometer.  Just exactly what do they tell you? I've bought one  because I'd assumed if a battery had a dead cell, for instance, it would show up on a voltmeter.

The little balls in the hydrometer tube have slightly different densities (more dense at the bottom). So the more dense the battery fluid is, the more balls will float to the top. Sulfuric acid is considerably denser than water, so the density of the solution indicates how much sulfuric acid is in it. (And any sulfuric acid no longer in the solution is attached to the lead plates as lead sulfate.)

A voltmeter can't distinguish the between a battery with one near-dead cell, and a battery that's just a little shy of a good charge. I had a battery like that; the voltmeter read basically "good enough," particularly after a good ride or a night on the trickle charger, but then the hydrometer informed me I had one marginal cell and one near-dead.