I tried that ,didn't help.I sent it back to the company.Maybee they will warranty it .It's only 5 months old.

Thanks for the info on harbor freight meter . It was a $20 walmart ETEK ,but I had to send it back to the manufacturer ,as the store warranty passed .I fried my stereo.I was spraying contact cleaner on the volume dial ,but forgot you can't do that with the power on .OOps.

I happened to find the instruction sheet for the battery maintainer I am using. It said the charger/maintainer is to be used on sealed lead-acid batteries only, so I have already erred. That also makes the question of removing battery caps moot. The instruction sheet says the maintainer will bulk charge at 2000 milliamps (2 amps) until the terminal voltage reaches 14.4 volts. It will then taper off the charge, holding the voltage at 14.4 volts, until the charge current decreases to 500 milliamps. It will then maintain the battery voltage at 13.6 volts. If the battery voltage decreases to 13.0 volts, the maintainer will switch back to bulk charge mode. Its described behavior agrees reasonably well with the behavior I observed.

I think the 13.6 volts for a flooded-cell battery is just a little high. Backing that up, today after the battery had been on float charge, I chose to tip it backwards, to see if any bubbles had been trapped under the plates. A good-sized bubble rose from each of the six cells, which tells me the float charger has been dissociating water from the electrolyte. Over time, this would run the battery dry. Note that a sealed battery would probably have some provision such as a catalyst for recombining this dissociated water, where a flooded-cell battery allows the water to be replenished. I think that, if you plan to use some sort of automatic battery maintainer on a flooded-cell battery, you will need to check the electrolyte every month or so.

Charon,
You're right, 13.6 is a little high for a normal float charger, w/ most being at 13.2 - 4. But in cooler weather 13.6 is not a problem, and it will use very little water also. In very cold weather, float voltage can even go into the 14v catagory, and be fine and also use little water. A hi $ temperature compensating charger will change the float voltage automatically according to the temperature.
There are charts on some battery sites showing what temps will tolerate what float voltages. I do know that in hot temps of 95 deg+, 13.2 should be a max voltage to not loose water.

Also, I have always used the same float chargers on SLA AGM as I use on regular lead acid, and have never had a problem, even tho the AGM have a little higher standing voltage.