Question for the experts - the standard bike battery (on a GL1200) I was using just wasn't lasting. My bike tech recommended an Odyssey extreme PC680 (called a nonspillable drycell battery) which, despite the premium price, I bought. First year was fine but over winter I put a battery maintainer on it (The same one I use with good results on my car, truck and tractor).
Come spring the battery just didn't have the charge to start the bike even after a charge with a regular charger. Took the battery back and the dealer (reluctantly) replaced it. Long story short the new battery did the same thing.
So my question - are some types of batteries not friendly with long term trickle chargers?
Oh boy... this one is a hot topic in the homebuilt aircraft world where Odyssey batteries are very popular. After much experience in that arena it has become clear that Odyssey Absorbed Gas Mat batteries and other similar AGMs do NOT like float chargers. In fact float chargers or battery minders tend to drastically shorten the lifespan of these batteries.
One of the joys of the AGM battery technology is that its self-discharge rate is very low. This low self-discharge characteristic leads to virtually no need to top up the battery regularly.
As a case in point, I purchased a pair of PC680's for my two airplanes. One was intended for my older, flying airplane, while the other was intended for my new aircraft which at that time was in the final stages of construction. After performing a load test on my 'old' PC680 installed in my flying airplane, I opted not to replace it. At 8 years of age it was showing lots of life. The "new" airplane took longer to finish than I had hoped, so its "new" PC680 was actually two years old before it was used in earnest.
I still have the second "new" PC680 on the shelf. In fact it has been on the shelf for two years now. As an experiment I refused to charge it for six months - I just wanted to see how it would do. Open-circuit voltage after six months was still 12.7 volts (Odyssey batteries seem to exhibit a slightly higher open circuit voltage than do flooded lead acid batteries - don't ask me why). I load-tested the battery after 6 months on the shelf and it showed great vigor. I recharged it with a normal high-current charger and, after 8 hours of charge, put it back on the shelf for another six month test. At the 12 month point the results were identical. Again I load tested it, recharged it and put it back on the shelf but had to press it into service for a few days last year to get the lawn tractor through the final throes of grass cutting for the year, then the battery went back on the shelf again. As luck would have it I tested it just the other day, this time after nine months of being ignored on the shelf. Results were nearly identical to those achieved after six months of being ignored. Quite impressive.
After talking to the Odyssey tech support folks it became clear the Odyssey likes to be recharged at a fairly high rate. According to the manufacturer the best charger for an Odyssey is a good engine-driven alternator.
Oh, I should mention that the battery in my old airplane is still going strong. Earlier this month it again passed the load test with flying colors. It's now 10 years old.