Sadly, the bike hasn't been seeing much use recently so I've been leaving it on the tender a lot. Yesterday when I was tinkering on a few bits I could hear the battery boiling while it was on the tender. When I took it out that day I needed a jump from a friend to get home. I haven't checked the water level yet but I'm pretty much set on getting a new battery. My old Yuasa is just about done anyway.
The question is, if the battery tender causes my current battery to boil, do I have to worry about toasting my brand new Odyssey PC680 I wanna get by leaving it on the tender?
it wasnt boiling, there is just hydrogen being made. its "fizzing". Its normal.
http://www.batterystuff.com/tutorial_battery.html (http://www.batterystuff.com/tutorial_battery.html)
The boiling could mean you're overcharged, or charging too fast. You should probably check the charger just to be sure
Two possibilities, the first is what Dan said, the battery charger is overcharging. The second is the battery is shorted.
To see if the charger is bad, hook the charger up to a known good battery with a voltmeter across the battery terminals. The charger should not go over about 14.5 volts and drop to about 13.2 volts as the battery approaches full charge. Momentary over charge won't damage the battery.
He Man is also correct that the charging process does release hydrogen gas, so some boiling is normal. A hot battery is not, though. Warm to the touch is OK, hot to the touch is not, nor is the smell of sulphur.
Ah. No sulpher and wasn't unbearably hot. I guess it was just me being paranoid.