Yesterday we bought a so-called "automatic", 1.5-amp battery charger that is normally $50, but on sale for $20. I've got it hooked up right now to our motorcycle's typical 12V motorcycle battery. (The battery is out of the motorcyle, sitting on our kitchen stove.)

The owner's manual states:

.............. "charging will continue until the battery voltage reaches approximately 14.4 V and the charge current has reduced to about 0.5 amps. At this point the amber Charging light will turn off and the green Charged light will turn on. At this point the internal charge reference will change in order to maintain battery voltage at 13.2 volts. Under this condition, called Maintain, most batteries can be left charging indefinitely."

The reason I am posting this is that the charger has been on the battery about three hours and I'm starting to get a bit concerned. The battery voltage at 11:40 AM was 13.93 and right now, 12:06 PM, it is 13.96, so the voltage is rising very slowly, indeed. The battery water levels are good and there is a fair amount of bubbling taking place as the charger charges the battery.

This is a 1.5-year-old Yuasa battery and I don't want to accidentally kill it.

1. Is it OK to charge a 12 volt motorcycle battery to 14.4 volts?

2. Does the above automatic sequence of voltages sound appropriate?

3. Do you think it is safe to leave this automatic charger hooked up to the battery continuously?

Thanks for any advice.

Edit: As of 1:36 PM, voltage is 14.00. At this rate, the thing is going to take another 2 or 3 hours to charge. Is this unusual for a 1.5 amp charger?

 

yes, yes and yes.
1.5 amps will take a while to charge your battery. according to the owner's manual, it has a shut-off and should not damage your battery. what you have is an overnight charger.

 

Thanks for the information.

As of 2:36 PM, voltage is 14.00. So, for the last hour of charging there has been abosolutely no change in voltage.

Apparently, the time it takes the charger to get the voltage to go from 14.00 to 14.40 could be many hours.

 

Yikes! As of 6:57 PM the voltage is 14.50 volts, but the charger is still charging. I assume the 0.5 Amp criteria has still not been met, so on goes the charge cycle.

Just in case the new charger is faulty and I know when to pull the plug, what is the maximum voltage a 12 volt battery can be charged to without damaging it?

Thanks for any information.