Denny,
If you don't have a battery hydrometer, you need one. Preferably one that has a temperature adjustment scale, but those can be hard to find. Otherwise, use a thermometer to check the electrolyte temperature when you use the hydrometer; add four gravity points (.004) to the hydrometer reading for every 10° F above 80. Subtract in the same manner for temperatures below 80°.
It could be that you need to leave the charger connected longer, as has been suggested.
If the charge rate is not changing, there might be a shorted cell, which you can find with the hydrometer- the shorted cell will have lower specific gravity than the others.
The process of cycling the battery - repeatedly discharging and recharging- works on some batteries, and you have to leave the battery completly discharged for 12 hours or more before recharging. That cycle can take a long time. My experience with that practice has been mixed- it seems to do better on batteries that are only a couple of years old and which have no other issues than being sulfated from lack of charging. If the battery has dried out or the plates have shed, you won't gain anything by cycling. Unfortunately, you can't tell if the plates have shed unless you can charge the battery at a high enough rate to get the electrolyte bubbling like a pot of water on the stove- 50-60 amps for about 5 minutes will usually do it.
Hope this helps.
Harvester
