BATTERY CELLS GOING DRY

[FreeSwede]

My ride is a 1995 GL 1500 SE with a Roadsmith Trike conversion. I put in a new NAPA battery about two months ago. During the first month we took a ride a few days in length, and after returning the engine would not start, typical dead battery but strange because it was so new; I discovered the cells were very low on electrolyte -- thought it strange, filled them up and recharged the battery. We recently rode from our place in Southern Utah to San Francisco, gone for ten days. A few days after our return, engine would not start, again only clicking .... this time all the battery cells were almost totally dry. This can't be just a battery problem, there must be something causing this to happen. Perhaps an electrical short somewhere causing the battery to heat up ? Do I need to go through the whole wiring harness searching for a short somewhere? I am stumped and baffled, and could sure use your helpful ideas and suggestions. (There are no motorcycle mechanics within hours of where we live that will even look at a bike as old as mine).

[Wilcoy02]

I would take the battery to where you bought it. See if different battery will do the same. If it does then yes you have a problem.

[TwoTone Trike]

Hey FreeSwede, + one on what Wilcoy 02 said. It could save you a lot of time and effort. The battery should have a warranty on it.

[DenverWinger]

Check the voltage at the battery with the bike running, rev it up to 2500 rpm and see what the voltage is. Should be around 13.5-14 volts, much over 14 volts I'd suspect trouble (bad regulator, or bad connection to it somewhere). Over-voltage can boil out a battery....

[terryt]

I would also check the charging volts to the battery before fitting a new one

[ct1500]

A high charging voltage will deplete electrolyte and should not be much greater than around 14.2V. A wet cell battery is old technology and has been stressed over and over on the forums to use an AGM type which eliminates the maintainance of checking levels.

[dingdong]

A high charging voltage will deplete electrolyte and should not be much greater than around 14.2V. A wet cell battery is old technology and has been stressed over and over on the forums to use an AGM type which eliminates the maintainance of checking levels.

Ditto! Check alt. output voltage before going further.

[minimac]

A hole in the battery will drain it too! Give it a good look and make sure nothing is rubbing the battery itself. I'd put money on the voltage regulator/alternator though.

[WingAdmin]

GL1500's are power-hungry beasts, and both draw and charge at high levels. You are more than likely boiling off the electrolyte with a high charging rate. It's possible you might have a problem with your alternator, and you'll want to check that first.

Refill the battery using (ONLY) distilled water, charge it overnight on a good battery charger, then reinstall it on the bike. Put a voltmeter across the battery, start the bike, and check the charging voltage. It should not be much higher than 14 volts, 13.8 is ideal.

Next, you're going to want to get a replacement battery - and this time, purchase an AGM (absorbed glass mat) battery, instead of a wet cell battery. AGM batteries do not need filling, are nonspillable, and are much better at absorbing and producing the power required for your GL1500.

I had a Yuasa AGM in my GL1500 for many years, and have now had an MotoBatt AGM for a year with great results.

[FreeSwede]

Many thanks to all eight fellow Wingers who have left me good suggestions. I will follow-up on all. Several months ago I had a local fellow-rider (Way more experienced than I since he's been riding and maintaining and repairing bikes his entire life - if it weren't for him I'd be a total gonner!) install a new 90 AMP Lactrical Alternator, anticipating adding additional lighting which I have never had time to actually do yet (Life Happens). I was vaguely aware of the AMG sealed batteries, and now wished I had purchased one of those instead of the electrolyte type; I'm not sure why I didn't. I'll check all the voltages you guys recommended. Thanks so much for the help.

[Sadanorakman]

Here's my take...

DON'T fit an AGM battery, UNTIL the problem is firstly fixed!

An AGM battery is an excellent piece of technology, but fitting one will not magically fix an underlying problem! If the alternator's regulator has failed, as I suspect, then it would similarly cook the (expensive) AGM battery!

If the battery is seeing more than 14.2V with the engine at mid revs and all big electrical loads turned OFF, then the alternators regulator is just not doing its job properly, and it may only be the battery that's actually holding it's output Voltage down at all! DON'T do the following, but if you were to disconnect the battery with the engine running and a faulty alternator regulator, then the alternator output voltage could hit 60 volts or more, and fry pretty much everything... ecu, ignition, instruments etc... the same would happen once all the electrolyte has boiled completely below the plates if the regulator is stuffed, so lucky it never got quite that low!

If the electrolyte is disappearing that quickly, then there just MUST be over-charging taking place. There is no other logical reason for a lead-acid battery to be losing all that fluid so quickly. I know someone suggested a leak, but remember that it is made of six individual 2V cells. How likely is a leak that breaches all six cells? ...not at all unless the whole battery case has a crack along it. It's most likely just boiling off due to overcharging.

Regards, Craig

[FreeSwede]

Thank you, Craig Sadanorakman ! For your well-written and extremely clear reasoning and directions. It really makes sense and I will follow up asap. Thanks again.